Ray50,

For UHF try the mant940. I read reviews about it and they are very good. Wu-infinite posted about it on page 190 of this thread with pics. They are selling it at walmart for less than $40.00.

Killabee44 thanks. I may have one already as I was tring to get DTV at my daughters house only about 15 miles from towers. We went with powered rabbit ears (UHF/VHF) so she can still watch VHF analog. I still have the 940 waiting to go back to W*mart. I will give it a try this weekend, however I am old school when it comes to antennas and have always believed that bigger is better. Seems like a 6' yagi would be better than that small antenna BUT maybe I will be learn something new.

Killabee44 thanks. I may have one already as I was tring to get DTV at my daughters house only about 15 miles from towers. We went with powered rabbit ears (UHF/VHF) so she can still watch VHF analog. I still have the 940 waiting to go back to W*mart. I will give it a try this weekend, however I am old school when it comes to antennas and have always believed that bigger is better. Seems like a 6' yagi would be better than that small antenna BUT maybe I will be learn something new.

No problem. I also believe that in general the bigger the antenna, the better the reception will be. Its just that I live in Florida and hurricanes destroy large antennas. Hurricane Wilma was really bad in my area.

When doing my research, I wanted an antenna that could receive VHF as well as UHF. I chose the MANT950 based on the reviews. When it is up and installed, it is supposed to be about 6' across but is just one plastic pipe, so less for a hurricane to grab on to.

rawise -- at or below roofline mount plus high vhf reception (come 2009, Baltimore will have 11 and 13) points to the Channel Master 4228. If you want to get Philly and/or Lancaster you'll probably have to get above the roofline (otherwise your house will block the signal) and put in a rotor (or use multiple antennas), and a different antenna might be appropriate.

Given that a simple UHF loop works, the 4221 MIGHT work, but at 48 miles I'd go for the 4228 anyway, as inexpensive insurance against having to mount an antenna twice.

Just to put in my $.02. I have a pair of Antennacraft MXU59 antennas mounted in my attic, pointing to 2 different cities. With this UHF antenna, I pick up analog channels 7 and 9 in Wausau crystal clear. The towers are 62 miles away. I would think that these antennas will work perfectly fine for upper VHF when the switch comes.

I put up an Winegard HD8200 (on roof) to pick up DTV ~60 miles away. While this worked 'OK' I had a poor signal with dropouts in bad weather and after leaves came out. I then mounted an HD9095P UHV antenna 4 ft. above the 8200 and combined the two. UHF wasn't much better so I tried disconnecting the UHF section of the 8200 and saw an improvement. I have been watch DTV (HDTV) for months with signals 50%-80%. Now that the weather is better I an thinking about replacing the 'very directional high gain' 9095P with maybe an 8-Bay like the CM4228 or the Winegard 8800. Anyone have experience switching between a multi-bay and a single reflector type antenna. How about multipath rejection. (BTW the antenna has a Winegard AP-8275 pre-amp also)
Thanks

ray

combine your hd8200p for vhf/fm with the 91xg for uhf mounted about 3.5' apart. I tried the cm 4228 and found that the cm 4228 does not tame multipath well from the trees. I have some big trees here. I combined the hd8200p with the 91xg at my home and found that I had the best results with this combination. I tried a ton of different antenna combinations here the last 23 years.

The Ap 8275 has very high gain for vhf and uhf and might be alittle high for you if you have stations less than 30 miles away with short run of coax and few splits.

when you combine the 2 antennas, you may want to amplify uhf and pass the vhf from the hp8200p if you can and examine if the ap8275 is the right preamp for your conditions.

you should not combine the hd8200p and a uhf antenna together with a standard 2 way combiner. you would need to use a cm0549 vhf/uhf combiner or can use a preamp with dual vhf/uhf inputs (if the isolation is accepable between bands).

see picture of my install showing the big trees.

you may get alot of opinions but I can honestly say from experience that the 91xg hd8200p combination tames multipath well and the 91xg out performs the uhf portion of hd8200p and does better on channels than the cm4228.

I live in an apartment and am considering buying a DB2 to use indoors. I'm curisous to see if any of you also use this antenna indoors, and if so what do you use as a stand? Thanks!

I had my DB8 hanging in my attic for a while. I used an old broom handle and hung it on a nail on the joist. Obviously you cant do that in an apt, but maybe will give you some ideas .

I live in an apartment and am considering buying a DB2 to use indoors. I'm curisous to see if any of you also use this antenna indoors, and if so what do you use as a stand? Thanks!


I also live in a apartment and I have a homebuilt DB-2 on a 1x3 board and I have a three sided outside wall closets and set it leaning against the wall over the hanging rack shelf. But as mounting the DB-2 I would do it take a 1 1/4" round wood rod and get a 1x4 for a base and mount the wood pole with a long screw from bottom of the base and go though the pole but don't tight it to tight just leave a little loose so you can turn the pole with little force. If you put it in the closet mount the pole on the end and make sure can swing round if need to and use the 3m tape that they use for the wall mount hangers put couple of those under the base board and top of the coat rack shelf. All the parts is from Lowe's or Home Depot. I got the 1x3x24 board from HP for $1.80. With the way I mount my I pick up station 60 miles away with no problem even DT 8 & 11 comes in great. Now only if I can find a smaller rotor for the DB-2 that would be great.

-Willie

http://www.solidsignal.com/tech_help_CM777X.asp

1. Choose a location for mounting the indoor power supply as close to the television set and a 120 volt 60 Hz AC electrical outlet as possible.

-------
Am I going to have a problem with my setup? Currently I have a 25 ft run into my unconditioned (ie HOT and freezing) attic, an amp with fm trap, then 75ft to my tv.

if i follow the above instructions, the power supply for the amp will be 100 ft away from the antenna, right in back of the tv. Will it amplify or 'push' just as well as the one in the attic, 75ft closer did?

I bought a Channel Master 4228 UHF antenna and the Winegard 8275 preamp. I thought there was a chance that I could pick up VHF 7 with the 4228, but it seems that I am just too far away from the tower. What are my options for adding a VHF antenna? Right now I have the 4228 mounted on the side of my house, just even with the top of my privacy fence. I don't want the antennas visible from the road, and there are no buildings between me and the tv towers (well, none within 200 feet). Is there a small VHF outdoor antenna that I could hook up using a Jointenna? All of the VHF antennas I've seen are those huge roof top models. With the UHF antenna I have now, the signal is at about 20% for VHF 7, I only need a little better signal to be happy. If I added a small VHF antenna and could get to 40% that would be perfect.

Any ideas?

Also, since my antenna isn't above my roof line, I didn't know if I still need it to be grounded. Will that improve any signal, or is it just for lightning protection?

Also, since my antenna isn't above my roof line, I didn't know if I still need it to be grounded. Will that improve any signal, or is it just for lightning protection?
If your CM 4228 won't get the Vhf station you want add a VHF High Band Yagi.
Look at the Winegard YA1713 VHF High Band Antenna.(SOLIDSIGNAL WEBSITE)
Grounding is mostly for lightning protection.

Channel 7 is KMBC 9 in Kansas City. I'm in Ottawa, KS 66067. What is the difference between the joiner and the Jointenna I looked at?

I didn't see his mileage to the tower. I can say I have the CM4228 and I am getting channel 7 here extremely well from about 38 miles AND I'm shooting through 60' trees that are only about 25 feet from my antenna. The CM4228 is on a 20' mast at the gable end of my house.

Note that when you have a locals package, you get 10 days of programming for the HDTV locals in the EPG grid from Dish. The schedule in the PSIP data embedded in the OTA HDTV broadcasts only goes out a few hours. So, to me, the $5 fee is justified.


vttom, I also have Dish with the ViP622 and OTA for HD locals. From your comment about PSIP from OTA only going out a few hours, does this mean you are getting the PSIP info to show through the 622? All I get, and I have called Dish, is "Digital Programming" to show up for my OTA locals.

If you are getting PSIP info from OTA locals, how are you doing this? Dish tells me the 622 doesn't support this. I'm so ticked at them for not correcting this in the software of the 622 - if that's really the problem.

Thanks

Hi everyone. This looks like a helpful thread so I will ask my question here. I live in a southern suburb of Boston roughly 9 - 12 miles away from 11 transmitting towers ranging from 358 to 5 degrees on the compass. I want^H^H^H am forced to do an attic installation because my wife hates the way antennas look yada yada. I live within 2 miles of a small airport and near some tall trees. I'm also on top of a hill. I am concerned not about signal strength but mostly about multipath interference. I am thinking a directional antenna would be best in my case, but I am here to ask the experts what they think. Here is a list of my digital stations:
yellow - uhf WSBK-DT 38.1 IND BOSTON MA 358° 9.3 39
yellow - uhf WFXT-DT 25.1 FOX BOSTON MA 3° 8.6 31
yellow - uhf WGBH-DT 2.1 PBS BOSTON MA 358° 9.3 19
yellow - uhf WGBX-DT 44.1 PBS BOSTON MA 358° 9.3 43
yellow - uhf WLVI-DT 56.1 CW CAMBRIDGE MA 3° 8.6 41
yellow - uhf WBPX-DT 68.1 ION BOSTON MA 2° 9.0 32
yellow - uhf WHDH-DT 7.1 NBC BOSTON MA 5° 9.2 42
yellow - uhf WBZ-DT 4.1 CBS BOSTON MA 358° 9.3 30
yellow - uhf WCVB-DT 5.1 ABC BOSTON MA 358° 9.3 20
green - uhf WMFP-DT 18.1 SAH LAWRENCE MA 2° 9.0 18
red - uhf WYDN-DT 47 DAY WORCESTER MA 2° 9.0 47
Like I said before I'm concerned about multipath so I am considering the Terrestrial Digial 42XG as an option for the attic installation even though it is an "outdoor" antenna. I am also considering the Channel Master CM 4221A bow tie style antenna which is more prone to multipath obviously. My questions are do these look like viable solutions in your opinions? And is the 42XG overkill for me since the range on it says 10-50 miles from transmitters? I am thinking that since this is an attic install the gain and range will be far less, which should work out okay for me since 9 miles is the sweet spot. Any advice will be appreciated. I am most interrested in OTA HDTV. Thanks!

vttom, I also have Dish with the ViP622 and OTA for HD locals. From your comment about PSIP from OTA only going out a few hours, does this mean you are getting the PSIP info to show through the 622? All I get, and I have called Dish, is "Digital Programming" to show up for my OTA locals.

If you are getting PSIP info from OTA locals, how are you doing this? Dish tells me the 622 doesn't support this. I'm so ticked at them for not correcting this in the software of the 622 - if that's really the problem.

ThanksNo, the 622 does not display the PSIP data. The behavior as you describe it is normal. I can look at the PSIP data if I use the ATSC tuner built-into my HDTV.

I live in a southern suburb of Boston roughly 9 - 12 miles away 9-12 miles away? You could probably do fine with tin foil and a coat hanger. Seriously, have you tried a simple indoor UHF loop or bow tie? You might be surprised.

How far are you from the broadcast towers? The DB2 is a UHF only antenna (with some limited performance for the upper VHF channels), are all of your digital stations on UHF? If you post your zip code, we can look up the local stations and tell you if the DB2 is going to cut it.

As for mounting the DB2, since it is not that large, there should many way ways to do it. Build something yourself with a PVC pipe or wooden pole and a flat piece of wood for a base. Or mount it high up on a wall facing the broadcast towers.

76301.

JR

If you are concerned about multipath and all your channels are uhf.

prefer the 43xg over the 42xg, cm4221, db2, rs u75r.

just went through the exercise. spent all afternoon in a hot, yucky, cramped attic and the 43xg was the best performer in there...period!

also at my home, I struggled with a 5,000,000 watt station 7.8 miles from the home on the other side of trees. tried all the antenna above and the 43 xg was best at taming the multpath.

So do not be concerned with overkill...non issue. the cushion will come in handy trust me.

Excellent Rick! Thank you for the info, I will seriously consider the 43xg now. Appreciate it. I'll post back with results

I didn't see his mileage to the tower. I can say I have the CM4228 and I am getting channel 7 here extremely well from about 38 miles AND I'm shooting through 60' trees that are only about 25 feet from my antenna. The CM4228 is on a 20' mast at the gable end of my house.

Be careful. The 4228 has a huge "suck out" area with low gain near the top of channel 7. See the last graph here: http://www.hdtvprimer.com/ANTENNAS/comparing.html

Reception of WKBW, an analog channel, will still work, but with a slightly softer picture. Reception of digital on channel 7 will be much harder.

I'm moving my attic antenna outside to a 12 foot pole on the peak of my roof.

I will set the base of the pole on my ceiling joists and cut a hole in my roof near the peak which is about 5 feet above the joist. That should allow my 12 foot high antenna to withstand substantial winds without any wires holding the mast up.

Is there any reason I can't use 1 inch pvc for the mast?

Should I do a ground wire to the peak for lighting protection?

I had to go learn what you meant by "suck out" area. :) And fortunately, WKBW's digital HD that MAPS to 7.1 is actually 38-1 so ... when I first read your response I was wondering why 7 digital would be harder until I realized you meant actual channel 7 VHF. (I'm still learning and easily confused)

I didn't get the 4228 with any thoughts of using it for VHF. And while I found it interesting that it received some of the VHF channels so well at these distances, I remove them after a scan anyways. I got the antenna for local HD only. The rest I get on satellite.

I had to go learn what you meant by "suck out" area. :) And fortunately, WKBW's digital HD that MAPS to 7.1 is actually 38-1 so ... when I first read your response I was wondering why 7 digital would be harder until I realized you meant actual channel 7 VHF. (I'm still learning and easily confused)

I didn't get the 4228 with any thoughts of using it for VHF. And while I found it interesting that it received some of the VHF channels so well at these distances, I remove them after a scan anyways. I got the antenna for local HD only. The rest I get on satellite.

That makes sense.

As near as I can tell, the idea that the 4228 is a good VHF antenna began in Connecticut, where WTNH-DT is on channel 10. The 4228 actually does pretty well on channel 10. Due to the dynamics of Forums, that lore has spread out to other geographical areas where the well-intended advice turns into misinformation.

That makes sense.

As near as I can tell, the idea that the 4228 is a good VHF antenna began in Connecticut, where WTNH-DT is on channel 10. The 4228 actually does pretty well on channel 10. Due to the dynamics of Forums, that lore has spread out to other geographical areas where the well-intended advice turns into misinformation.

Ahh... so THAT's where it came from... hehehhe...

Actually... I get channel 2 VHF on the 4228 as well... and channel 4... both from about 38 miles. Channel 2 is completely understandable, but not what I'd call watchable. Channel 4 is snowy but you could watch it in a pinch. channel 7 comes in quite clearly, but as I said... that's kind of a novelty and I only really mention that it receives them because I was surprised that it got them at all. When I bought the 4228 I bought a UHF antenna. As a UHF antenna I'm pulling in stations from Toronto (about 43 miles to the CN Tower from my house) off the BACKside of the antenna. If I ever get a rotor, I think I'm in a good spot to pull Buffalo, Grand Island, Toronto and possibly.... possibly... Rochester, but that might be asking a bit much as I think I'm 63 miles from some of the Rochester transmitters.

Be careful. The 4228 has a huge "suck out" area with low gain near the top of channel 7. See the last graph here: http://www.hdtvprimer.com/ANTENNAS/comparing.html

Reception of WKBW, an analog channel, will still work, but with a slightly softer picture. Reception of digital on channel 7 will be much harder.
I would also be careful with NEC computer simulation results posted on hdtvprimer....
Unfortunately, in many cases, it's all we got.....

Kerry Cozad (Dielectric Antennas) measured gain on REAL antennas,
including CM-4228 (see the Excel spread sheet):
http://hdtv.forsandiego.com/messages/4364/3476.html?1126051755

Although Kerry only measured odd channel numbers in the VHF range,
CH7/9/11/13 had nearly same gain (9 dBd +/- 0.5 dB, incl. "ground bounce gain").

In this thread on 24Sep2005, <bobchase> (Stn Engr in Houston) posted
spectrum analyzer received signal levels for 8 OUTDOOR antennas, incl. CM-4228:
http://www.avsforum.com/avs-vb/showthread.php?p=6245872&#post6245872
Note that NTSC CH8 (KUHT) and DTV CH9 (KUHT-DT) come from same antenna structure.
You'll have to really zoom in on the *.pdf to see the different colors....

For CH9/11/13, CM-4228 exhibits only 3-4 dB less gain than W-G HD7210
(which has 3 VHF elements) and has about 5-7 dB less gain for CH8...so maybe
there is a loss of 3-4 dB on CH8 relative to higher channels.
[PS: Compare the peaks vice in-between video levels, which varies with picture.]

Note the POOR performance for 91XG and SS-1000 in upper VHF band....
And the additional gain realized with a "big" VHF antenna...if you "NEED" it....

================================
Clearly, the very deep nulls in the frequency response depicted in the hdtvprimer
NEC SIM results for the CM-4228 are an exaggeration in the computer's imagination....

Also note the hdtvprimer currently posted NEC SIM results for the CM-4228
(with and without screen connections) are MUCH WORSE than the earlier results
(I'm looking at a Jun2005 printout), which depicted -4 dBd (vice -11 dBd) gain on CH8
and -2 dBd (vice -7 dBd) gain on CH12.

Hi there

I am looking for a small Indoor antenna for my condo. My zip is 92618. I have a large sliding glass window that faces west. Any suggestions?

Thanks

Bushy

Hi there

I am looking for a small Indoor antenna for my condo. My zip is 92618. I have a large sliding glass window that faces west. Any suggestions?

Thanks

Bushy

I think you'll find that most people here will recommend the Terrestrial Digital DB-2. (some will persist in recommending the Silver Sensor by Philips, but it is really not in the same league as the DB-2). It is designed to be used outside, but it is small and svelte enough to be used indoors in most homes/apartments. I've got one behind a big chair. ;)

This is something of an announcement for DB-2 fans: up until now, many people have been hesitant to try the DB-2 because indoor antenna buying is so hit-or-miss and you really need to be able to return a non-performer--folks were nervous about buying it from AntennasDirect.com. Well, the DB-2 is now available at Target (online only). You can buy it online, and if it doesn't work out for you, return to your nearest B&M. :cool:

Cheers,
Rev

Been lurking through this thread and regret I have not gotten into HDTV over the air transmissions ealier. I have a very basic understanding of antennas through wifi deployment, but now I am looking at serving hdtv- a bit different imagine.

I work for a residential developer and we have a few new building coming up in the Chicago downtown area (South Loop, specifically Roosevelt & S. Michigan.). One 20 story and one 10 story building. I've been approached by numerous local cable providers trying to get us to subscribe. Would deploying an hd antenna on the roof be a viable alternative to offering free high quality channels to the buildings residents?
I am willing to spend more time studying the art and science behind it, would I be able to follow through the deployment of the cabling and antennas myself or is it in my best interest to get a pro to do it? Any idea what the cost might be associated with this?

Thanks for any input.

I'm sure if you look hard enough you can find a commercial system which does what you're looking for. For example, my local Best Buy has probably close to 100 HDTV displays all showing the same programming. Tinkering with the input settings on one of the sets revealed that it's being delivered to each set via RF and the built-in ATSC tuner. You could probably use a similar system to distribute the HD OTA signals throughout the building.

However, you're only going to get the local network affiliates that way. I think the reality is that most people will still opt for a more-extensive cable-channel line-up in SD than for a OTA-channel line-up in HD.

Edit: Oh yeah. And what about people who want to get cable-modems? You'd better make sure you make DSL available if you don't offer cable.

What you want is an MATV (Master Antenna Television) system. At least one person who hangs out here has professional experience in them. Take a look a the following thread to get an idea of some of the issues involved:

http://www.avsforum.com/avs-vb/showthread.php?t=779057

I think what he wants is a second free alternative to Hd broadcasting, not a another whole subscribe system. If you're at 10 or 20 stories then you're probably going with a flat top tar shingled roof. You'd be able to go with a two antenna system. One pointed at the Hancock and another at Sears in order to get all local stations, then going into a dual antenna preamp trap. You would then amp distribute each floor or every 100 or so feet. I would only go with this an altnerative option to the units. I don't know of too many condo buyers only opting for free broadcast. You'll still have to wire the units up for cable, either get RCN or Comcast to split that cost if they want your customers.

What ever you do don't go with the outlets half way up the wall or an outlet directly over the firplace. If anything, on the side of the fireplace. I've been inspecting new 4 flat construction in Jefferson Park and that seems to be the new trend. It is a must to at least prewire the bedrooms and least two places in the den with a coax outlet. You might also want to consider a coax hot box if you decide to let tenants have DBS.

acesea: You're going to need a pro. If for no other reason, that it probably requires a license or two to do the wiring and put the antennas on the roof. As jtbell says, what you're looking for is an MATV system.

I would also be careful with NEC computer simulation results posted on hdtvprimer....
Unfortunately, in many cases, it's all we got.....

In this thread on 24Sep2005, <bobchase> (Stn Engr in Houston) posted
spectrum analyzer received signal levels for 8 OUTDOOR antennas, incl. CM-4228:
http://www.avsforum.com/avs-vb/showthread.php?p=6245872&#post6245872
Note that NTSC CH8 (KUHT) and DTV CH9 (KUHT-DT) come from same antenna structure.
You'll have to really zoom in on the *.pdf to see the different colors....
================================
Clearly, the very deep nulls in the frequency response depicted in the hdtvprimer
NEC SIM results for the CM-4228 are an exaggeration in the computer's imagination....


Bob Chase's measurements were not intended to show this specific characteristic of the 4228 antenna.

The Chase measurements on channel 8 are limited by the skirt selectivity of his spectrum analyzer. In this case the strong channel 7 analog signal is actually showing up as response in the lower section of channel 8. That effect is likely causing the tilt on channel 8 of the three VHF antennas shown on the graph. To see the equipment limitation more clearly, look at the wide shoulders on the analog signal on channel 20 in his UHF plot. The same tilt evident on channel 8 also shows up on channels 27, 35, 46, and 48 with the analog channels 26, 34, 45, and 47 below. If you try to compensate for the effect to impute a channel 8 "suck-out" number for the 4228, it's still in the 8 db range, but that estimate can't be trusted. According to the NEC calculations on HDTV primer, the "suck out" gain minimum of the 4228 on channel 8 is about 11 db.

Even 8 db of suckout sure makes the adaptive equalizer in the receiver work hard.

Ahh... so THAT's where it came from... hehehhe...

If I ever get a rotor, I think I'm in a good spot to pull Buffalo, Grand Island, Toronto and possibly.... possibly... Rochester, but that might be asking a bit much as I think I'm 63 miles from some of the Rochester transmitters.

You should do fine with Rochester stations. I grew up in Bergholz. (3 miles from Sanborn) We got the VHF stations in Rochester and most of Sanborn is higher than Bergholz.

Thanks for the info thus far everyone. I will look into the Master Antenna Television thread and related material. In the meantime, anyone know of or have experience with a professional in the Chicago area? I am open to recommendations.
Also, escopa, when you say that I should get RCN or Comcast to split the cost.. are you refering to having them pay for a part of the free ota system? Just want to be clear on this. I have a lot of local cable reps killing for my business so I want to know that I have leverage in some things which I can use.

Whoa this topic has too many pages.. but has anyone tried to build their own DB2 Antenna?

Bob Chase's measurements were not intended to show this specific characteristic of the 4228 antenna.

The Chase measurements on channel 8 are limited by the skirt selectivity of his spectrum analyzer. In this case the strong channel 7 analog signal is actually showing up as response in the lower section of channel 8. That effect is likely causing the tilt on channel 8 of the three VHF antennas shown on the graph. To see the equipment limitation more clearly, look at the wide shoulders on the analog signal on channel 20 in his UHF plot. The same tilt evident on channel 8 also shows up on channels 27, 35, 46, and 48 with the analog channels 26, 34, 45, and 47 below. If you try to compensate for the effect to impute a channel 8 "suck-out" number for the 4228, it's still in the 8 db range, but that estimate can't be trusted. According to the NEC calculations on HDTV primer, the "suck out" gain minimum of the 4228 on channel 8 is about 11 db.

Even 8 db of suckout sure makes the adaptive equalizer in the receiver work hard.
But the "skirt" above N20 is also N21-LP....
And, of course, "skirt" selectivity should affect all antennas equally....

Only the frequency response across a particular channel is of interest,
rather than the total amount of "suck-out" across multiple channels....

Across D09, none of the antennas exceeds +/- 2 dB, which is hardly any problem....
If there truly is a "skirt" effect, it only adds another 2 dB unevenness across the band.
Which is STILL within the ballpark of what a receiver will have to cope with
using ANY of the antennas on channels D27, D35, D36, D46 & D48.

Plotting the more or less stable signal points (NTSC Video and Audio carriers),
yields the freq response shown in the below jpg.....note that CM4228 is relatively
flat across N08, although at a level about 6 dB lower than CH11-13.
NEC SIM runs also predicted a huge (~10 dB) frequency roll-off across CH11,
but on-air measurements only shows 3 dB.....

I just don't see evidence of huge, sharp nulls in the frequency response....
We have to bear in mind that REAL antennas will have different element
spacings and separations, which spreads out any resonance effects....
and "fills-in" deep nulls....so they're much milder freq response variations....

I chose to plot the gain values relative to the W-G HD7210 (no gain specs avail),
you can look at the CM3671 and VU-90XR NEC SIM on hdtvprimer and
CM3671/CM3016 specs on stark electronics website....
You'll find rough agreement, although the slope magnitudes will vary...

=============================
The uneven response for CM4228 on D05 and D09 has the rippled "look"
of multipath.....which causes the signal to vary with frequency over time....
so we should be careful cuz we're only looking at a snapshot.....

Multipath "signature" is also seen with SS-1000 (brown) on D24, D27 and D32.

Although gain is important, the ability to reject multipath is also important...esp. for NTSC.
Obviously, a purpose built VHF antenna is going to have a better controlled F/B ratio.

Fortunately, modern 5th Gen ATSC tuners are much more tolerant
of multipath than earlier generation receivers....

So is a CM4228 as good as a purpose built VHF antenna--of course not,
but it's still worth trying when DTV moves to Hi-VHF.....many people
should find that it is more than "adequate"....and fits in the attic with a rotator...

Some might be lucky enough to find that their so-called UHF antenna also works
for CH2-6.....just as some find an old coat hanger is "good enough" now....

Just don't count on it.....YMMV.....

acesea- it sounded like you were going to foot the bill for installing the coax throughout the building. Get the cable company to install and foot the bill of wiring the building presheetrock. And you can always add to the bid, that they have to run a bi-wire system. One going to the roof (OTA) and one going to the street (cable). As a builder, I would never pay for an install that's going to an outside provider.

Plotting the more or less stable signal points (NTSC Video and Audio carriers),
yields the freq response shown in the below jpg.....note that CM4228 is relatively
flat across N08, although at a level about 6 dB lower than CH11-13.
NEC SIM runs also predicted a huge (~10 dB) frequency roll-off across CH11,
but on-air measurements only shows 3 dB.....

I just don't see evidence of huge, sharp nulls in the frequency response....
We have to bear in mind that REAL antennas will have different element
spacings and separations, which spreads out any resonance effects....
and "fills-in" deep nulls....so they're much milder freq response variations....

Just don't count on it.....YMMV.....

The CM4228 in Chase's graph looks flat on channel 8, but it really isn't. All real VHF antennas show a higher signal at the bottom of channel 8, but it's really channel 7 aural filling in the lower portion of channel 8. The CM4228 goes lower than the real antennas by 8 db. Yet, the calculation is not simply decibel subtraction. The skirts of channel 7 fill in the suck out. To me it clearly shows a greater than 8 db notch in channel 8.

The measurements of gain plotted on aural and visual carriers use insufficient data points to be useful.

I still believe the NEC calculations.

Whoa this topic has too many pages.. but has anyone tried to build their own DB2 Antenna?


I have built a home made DB-2 and it works great for me. I even pick up a DT channel 11 that is 57 miles away indoor also get DT on 8 that is 43 miles away also. Here the link on how to build DB-2

http://www.lumenlab.com/forums/index.php?showtopic=9613

Read it good and it really simple to build it only cost me about $8.00 to build it. At my old apartment which I had line of sight to Chicago that was 70 miles away and I locked on all Chicago DT station but WBBM CBS 2. If I was to put the antena in the attic I could get the Chicago station also.

Good luck building one.

-Willie

ch 11 57 miles...ch 8 43 miles ...on a double bow. receive how good.

I am going to try my double bow right now and see what I get.

ch 2 70 miles...come on.

acesea- You might want to give D.L. Markley & Associates a call. If they can't help you, then they might know of someone who can. They're in Peoria, but do a lot of work in the city. They have a web site that'll give you all the contact info.

ch 11 57 miles...ch 8 43 miles ...on a double bow. receive how good.

ch 2 70 miles...come on.
Obviously this is not normal, everyday reception. But such things can (and do) happen. There is an analog channel 2 about 245 miles away from me, that I can pick up with my 8-bay bow-tie UHF antenna, a couple of times a year. And a channel 10 70 miles away that I can get almost every day.

Just goes to show that there are other factors that make more of a difference in reception that the antenna itself. Such as location, location, location...and tropospheric conditions, weather, etc.

ch 11 57 miles...ch 8 43 miles ...on a double bow. receive how good.

I am going to try my double bow right now and see what I get.

ch 2 70 miles...come on.


Well Rick, I live in a 2nd floor apartment, there is 3 rows of 16 units I am on the far west building and on the westside of that building second in from the northside. Right now I have the antenna in the closet on the outside wall and it about 6 off the floor and it is faceing due east with slightly pointing to the sky and the analog channel 10 is digitaly trasmit on Ch 8 is northeast of me and analog channel 47 is digitaly trasmit on 11 and is northwest of me. And all other is in the UHF range.

How good do I get it I am using the Samung 260 as a reading. Channel 10 on 8 is reading 3 of 10 bars with no break up soild lock and the channel 47 on channel 11 it is rock solid also at 4 of 10 bars.

I did get Chicago Fox analog 32 which is on 31 digital but it had to be in the middle of my living room and just below the ceiling and it was a soild lock as well. I did not try the others station because my arm got sore from holding it up high. It about 74 miles away.

I did what most of the instructions in that link and made few mod and I am happy with it. At first I didn't think it would work but it proved me wrong it did work as well as my 4228 in some case it worked better than the 4228. So it is a sicence work but it work in my place and it my not work in your place or someone else, but you won't know until you try it and it was cheap and fun to build one. Some weekend I am going to try the DB-4 or make a 4220 / 4221 design and I will still have it under $10.00 to build one and best of all if it don't work you can take it apart and rebuild it or make a different one.

So let me know how your build one works out for you.

-Willie

Obviously this is not normal, everyday reception. But such things can (and do) happen. There is an analog channel 2 about 245 miles away from me, that I can pick up with my 8-bay bow-tie UHF antenna, a couple of times a year. And a channel 10 70 miles away that I can get almost every day.


Just goes to show that there are other factors that make more of a difference in reception that the antenna itself. Such as location, location, location...and tropospheric conditions, weather, etc.


Well the the Digital 8 and 11 is lock on soild everyday 24/7. Both through the Samsung 260 and the Polaroid 3234-B HDTV set. I don't have the analog side hook up, the digtial spoiled me :D so I don't watch analog channel.

-Willie

How good do I get it I am using the Samung 260 as a reading. Channel 10 on 8 is reading 3 of 10 bars with no break up soild lock and the channel 47 on channel 11 it is rock solid also at 4 of 10 bars.

when I tried mine here this morning...ch 3 was a mess, ch 5 was less of a mess, ch 9 was decent. Ch 20 and 33 56 miles away were snowy, and the local ch 14 8 miles away at 13kw was snowy.

A double bow is a double bow. lets face it . 3 or 4 out of 10 is typical of what to expect from a double bow tie lock or no lock. lets not make it sound like the homemade double bow will perform a miracle or will the results be typical for all users.

I could pickup ch 3 with the double bow and rs u75r antenna and it was watchable (barely)...would I sell it to a customer or suggest one here. NO

What does pickup mean anyway?

when I tried mine here this morning...ch 3 was a mess, ch 5 was less of a mess, ch 9 was decent. Ch 20 and 33 56 miles away were snowy, and the local ch 14 8 miles away at 13kw was snowy.

A double bow is a double bow. lets face it . 3 or 4 out of 10 is typical of what to expect from a double bow tie lock or no lock. lets not make it sound like the homemade double bow will perform a miracle or will the results be typical for all users.

I could pickup ch 3 with the double bow and rs u75r antenna and it was watchable (barely)...would I sell it to a customer or suggest one here. NO

What does pickup mean anyway?


Sorry Rick, it didn't work for you, But I don't get snowy picture on my digital 8 or 11 channel or any of the digital channel.

I NEVER said " the homemade double bow will perform a miracle or will the results be typical for all users."

I said " So it is a sicence work but it work in my place and it my not work in your place or someone else, but you won't know until you try it "

As your favortie XG-91 that would not work for me here, so don't lead others that your set up will work for everyone as you always do say. I just responded to SubaruB4 question I never said it would work for him just pointed the link so he can see for himself, and I was the only one responded to his question I see you didn't respond his question. And you always say "antenna science is not an exact science" Well it is a science, but you can't do the test from your place and find it don't work for you and then it don't work for anyone or anywhere else. It a work of science at everyplace where the antenna will be install, as Neil L said " Just goes to show that there are other factors that make more of a difference in reception that the antenna itself. Such as location, location, location...and tropospheric conditions, weather, etc." So it is a science.



-Willie

Hi guys - I'm needing some help on my antenna and improving my signal strength. I live outside Detroit, MI about 30 miles from the main antenna. I get most of my TV through DirecTV, but my receiver doesn't get the HDTV local stations - so I get those off the air.

I currently have a Phillips Silver Sensor UHF antenna - it's an indoor antenna but I've got it mounted outside.

My zipcode is 48103: here's the output from my address from antennaweb - only the digital stations are listed. The last number for each station is a relative signal strength off my D* receiver (0-100, 100 is perfect).

Antennaweb.org output

red - uhf WDIV-DT 4.1 NBC DETROIT MI 70° 32.0 45 88
red - uhf WKBD-DT 50.1 CW DETROIT MI 65° 27.2 14 51
red - uhf WTVS-DT 56.1 PBS DETROIT MI 75° 32.6 43 68
red - uhf WMYD-DT 20.1 MNT DETROIT MI 75° 32.6 21 28
red - uhf WJBK-DT 2.1 FOX DETROIT MI 72° 30.9 58 71
red - uhf WWJ-DT 62.1 CBS DETROIT MI 75° 32.6 44 71
red - uhf WXYZ-DT 7.1 ABC DETROIT MI 70° 29.6 41 60
violet - uhf WLNS-DT 6.1 CBS LANSING MI 319° 41.8 59
violet - uhf WTOL-DT 11.1 CBS TOLEDO OH 160° 46.6 17

I can get 4.1 fine, but 2.1 comes in with lots of pixelization. I'm trying to improve the signal so I can rely on the OTA for my wife to watch HDTV off the local stations (American Idol finale anyone? ;-) )

Ideas? - would an amplifier work? I found an old Radio Shack (so old the brand name was Archer!) amplifer, but it reduced the signal strength, I think it was only VHF.

[QUOTE A double bow is a double bow. lets face it . [/QUOTE]

A bow tie is just a dipole antenna with greater frequency response (broadband). It has the same performance of rabbit ears.

A DB2 is two bow ties in phase with a planar reflector. The combination provides some directivity and gain compared to rabbit ears (i.e. 5 dBd).

The lumenlab.com site also includes a lot of useful discussion on DTV reception issues (e.g. multi-path, SWR, baluns, coax loss, pre-amps etc.) and designs on really high performance antennas (e.g. log periodic dipoles, rhombics, co-linear arrays, 3 D reflectors etc.).

This weekend I posted a design for a monopole with 3 D reflector that cost less than $5 to build, has superior multi-path rejection and is capable of a gain in the 14 - 18 dBi range.

See post # 736 at:

http://www.lumenlab.com/forums/index.php?showtopic=9613&st=720

Hi guys - I'm needing some help on my antenna and improving my signal strength. I live outside Detroit, MI about 30 miles from the main antenna. I get most of my TV through DirecTV, but my receiver doesn't get the HDTV local stations - so I get those off the air.

I currently have a Phillips Silver Sensor UHF antenna - it's an indoor antenna but I've got it mounted outside.

My zipcode is 48103: here's the output from my address from antennaweb - only the digital stations are listed. The last number for each station is a relative signal strength off my D* receiver (0-100, 100 is perfect).
My advice would to be start by getting a better outdoor antenna with more gain rather than to try to boost the Silver Sensor. The Silver Sensor is a fine indoor UHF only antenna, but it is not really suitable for 30 miles with your color codes. Also, checking the FCC data, WJBK-DT Fox 2, currently on UHF 58, will switch to VHF 7 in February, 2009 after the analog shutdown. Oddly enough WXYZ-DT ABC 7 will stay on UHF 41. The Silver Sensor by itself will not get a VHF 7 station at that range.

Are you interested in trying to get Toledo or other digital stations? They are 40 to 50 miles in other directions and a broad pickup antenna may be able to get some of them. For your UHF stations, the Channel Master 4221 should easily get the Detroit stations and offers a shot at getting some of the other stations in Toledo & Lansing if you can aim it just right. But the future VHF 7 at 30 miles would be iffy for a CM 4221. Is there a size constraint for the antenna on your outside mount? Maybe a CM 4220 2 Bay or CM 4221 4 Bay combined with a dipole for VHF?

My advice would to be start by getting a better outdoor antenna with more gain rather than to try to boost the Silver Sensor. The Silver Sensor is a fine indoor UHF only antenna, but it is not really suitable for 30 miles with your color codes. Also, checking the FCC data, WJBK-DT Fox 2, currently on UHF 58, will switch to VHF 7 in February, 2009 after the analog shutdown. Oddly enough WXYZ-DT ABC 7 will stay on UHF 41. The Silver Sensor by itself will not get a VHF 7 station at that range.

I am currently using a Silver Sensor, but considering all the results I have been able to find from TV Fool (mostly -85 to -99) and Antenna Web (violet), I don't understand why it's performing so well at 51 miles. I have a CM 3043 amp, but even w/o it the reception is quite good in my attic. As I am in the LA area (Orange County), all my channels are within a 1 degree angle.

I wouldn't think it possible for a small indoor antenna to work at this range. I am looking at getting a larger antenna, such as a CM4221 (getting the 4228 in the attic would be a real chore), but with all the channels (46, including sub-channels) I'm getting, I guess I should just call it a day. I even had good results with the RS 15-1634, which doesn't even seem like a real antenna to me.

I am concerned about the move back to VHF in time as the Silver Sensor doesn't get it done there. I will try and find some 'rabbit ears' to see if that is all I would need for VHF, but that seems equally absurd at my distance.

Is it conceivable that aspects of my terrain and the fact that hills block signals from most other directions lead to these results? I am quite excited it works so well, but I am the kind of person that wants to know why something works... and if I can make it even better, that would be great.

I am currently using a Silver Sensor, but considering all the results I have been able to find from TV Fool (mostly -85 to -99) and Antenna Web (violet), I don't understand why it's performing so well at 51 miles. I have a CM 3043 amp, but even w/o it the reception is quite good in my attic. As I am in the LA area (Orange County), all my channels are within a 1 degree angle.

I wouldn't think it possible for a small indoor antenna to work at this range. I am looking at getting a larger antenna, such as a CM4221 (getting the 4228 in the attic would be a real chore), but with all the channels (46, including sub-channels) I'm getting, I guess I should just call it a day. I even had good results with the RS 15-1634, which doesn't even seem like a real antenna to me.

I am concerned about the move back to VHF in time as the Silver Sensor doesn't get it done there. I will try and find some 'rabbit ears' to see if that is all I would need for VHF, but that seems equally absurd at my distance.

Is it conceivable that aspects of my terrain and the fact that hills block signals from most other directions lead to these results? I am quite excited it works so well, but I am the kind of person that wants to know why something works... and if I can make it even better, that would be great.
You are in LA where the broadcast towers are up on the top of Mt. Wilson at over 6000'. This gives those towers a long clear view over much of the LA area and to the south of it. If you don't have hills or buildings blocking the signal path in the direction of Mt. Wilson, you can get away with a small UHF antenna at ranges that most other places can't.

Don't know what the power will be for the digital upper VHF stations when they switch over, but you could make your own dipole antenna with the length optimized for the middle of upper VHF, get a VHF/UHF combiner, and see how the picture quality looks for the current upper VHF analog stations. If you get decent pictures for them, chances are that your setup will work for the post transition. If not, you could get a dedicated upper VHF antenna such as the Winegard YA-6713 (http://www.winegard.com/offair/vhf.htm) which is reasonably compact.

> I am looking at getting a larger antenna, such as a
> CM4221 (getting the 4228 in the attic would be a real
> chore),

If you have room in the attic but the problem is getting
a 4228 through the hatch, consider the Winegard PR-8800.
Gain is a tad less than 4228, but much better than 4221
and has better multipath rejection. The PR-8800 comes
folded up, you could put it through a doggie door.

uh... the 4228 comes apart. :)
The screen comes off REALLY easily by bending (or UNbending) a few tabs. And I would think it would fit through a hatch easily without the screen attached. Then you can just reattach the screen. Considering the results you're already getting though, the 4221 might be easier.

Don't know what the power will be for the digital upper VHF stations when they switch over, but you could make your own dipole antenna with the length optimized for the middle of upper VHF, get a VHF/UHF combiner, and see how the picture quality looks for the current upper VHF analog stations. If you get decent pictures for them, chances are that your setup will work for the post transition. If not, you could get a dedicated upper VHF antenna such as the Winegard YA-6713 (http://www.winegard.com/offair/vhf.htm) which is reasonably compact.

Thanks for the info. So, channels 2-6 are going away? I was trying to figure out exactly which channels were being auctioned and could only confirm 52-69. Channels 2-6 are so far down the ladder it makes me wonder why they are there.

I tried out analog VHF with the Silver Sensor and channels 2, 4 & 5 were predictably bad. However, some channels in the 7-13 range were halfway decent.

I found some rabbit ears, which I will try out. I may try them with a reverse splitter at first, but I'm sure a proper combiner would be better.

uh... the 4228 comes apart. :)
The screen comes off REALLY easily by bending (or UNbending) a few tabs. And I would think it would fit through a hatch easily without the screen attached. Then you can just reattach the screen. Considering the results you're already getting though, the 4221 might be easier.

The attic opening is 20x28" with about 35" available on the diagnol. I've heard that some of the rivets can be drilled out on the 4228, but didn't know that the screen comes off. If the screen is one piece, I would still have a problem, if it is sectional, my prospects would be better.

A local electronics store (Fry's) has a bunch of 4228's on the shelf, but no 4221's. The box for the 4228 is huge and won't fit in my car. I would probably have to have it shipped.

The Winegard PR-8800 might be a better choice as it appears to be comparable or maybe something like the DB-4?

If channels 2-6 are going away, it probably doesn't make sense for me to consider a CM Crossfire or Advantage antenna, does it? These would be "fun" to install as I'd have to go between the rafters, etc. I once had a CM Quantum years ago when I was living in the San Diego area... that thing was a monster but worked pretty well (on the roof). Roof mounting is not an option for me now.

Thank you the suggestions.

The CM4228 screen is in 2 halves. The "seam" runs vertically. If you've got anywhere CLOSE to 35" on the diagonal, it should pass through that hole easily. You shouldn't have to drill out any rivets. What kind of car? You could use the same trick to get it home. unbox it, take the reflector screen off, stick it in your car and then reinstall the screen up in the attic. All you'll need is a small pliers to bend and unbend the tabs. When I get home, I'll go up on the roof and see if the whole antenna can easily be separated into halves. I don't remember how the horizontal bars are connected to each half. I don't remember those being riveted, but I could be wrong.

> The Winegard PR-8800 might be a better choice as
> it appears to be comparable or maybe something like
> the DB-4?

The DB-4 is comparable to the Winegard PR-4400 and CM 4221. (4-bay)
The DB-8 is comparable to the Winegard PR-8800 and CM 4228. (8-bay)

If you have room inside the attic, I recommend going with an 8-bay.
An 8-bay gives you more gain and less multipath.

If you have a low pitch roof, measure the height available. If you
don't have enough height you might have to look at yagis instead.

> If channels 2-6 are going away

You would have to check the plans for your area.

> CM Crossfire or Advantage antenna, does it? These would be
> "fun" to install as I'd have to go between the rafters, etc.

If you need VHF-HI, the 8-bays might be enough. A VHF-HI yagi like
the Winegard YA-1713 is only 35 inches wide. A VHF-LO antenna
will be about twice as wide.

The YA-1713 also comes folded up and will fit through a hatch no problem.

ch 2-6 is not actually going away. there are about 40 stations in the US that have been assigned or elected to choose vhf ch 2-6. some stations are in the process of trying to win an assignment/change there mind in hi vhf or uhf before everything is said and done. this is still a work in progress..

an act of congress (not the fcc) passed legistation specifying the digial tv spectrum. it has been assumed by fcc wording in documents, by word of mouth, and interpretation, and not written in legislaion. it can only therefore be assumed that the fcc would like to see the stations move to hi band vhf or uhf since doing away with ch 2-6 is not written in legislation.

if you have a vhf assignment in your market, it is a good idea to determine what is going on before you make a decision.

dont ya think?

Out of the box, the rear screens on my CM-4228 are 39.5-in wide and 36-in high.

Once you remove the two rear screens (via unbending tabs), the bowtie elements
are 36-in wide and 30-in high.
Hence it "should" fit through an opening that is more than 30-in on the diagonal.
If not, you'll have to drill four (or worst case eight) rivets. [Located on same piece as bendable tabs.]

The 39x41x5.5-in box fits rear hatch of Volvo Stn Wagon, but NOT via rear passenger door....YMMV...

The fol. pictures are for my son's CM-4228. (The ruler is 36.25-in long.)
Note that HIS bowtie elements are about 37.5-in wide and 28-in high!!!!

Hmmm, appears that HIS bowties came bent closer together than mine.....
Betcha NEC SIM runs would show that mine is ever so slightly better
at high UHF freqs and his is ever so slightly better at lower UHF freqs.....

Thanks for the info. So, channels 2-6 are going away? I was trying to figure out exactly which channels were being auctioned and could only confirm 52-69. Channels 2-6 are so far down the ladder it makes me wonder why they are there.

FYI: In ALL of Calif., Eureka CH3 is the ONLY DTV Channel Election in CH2-6 band.

> I am looking at getting a larger antenna, such as a
> CM4221 (getting the 4228 in the attic would be a real
> chore),

If you have room in the attic but the problem is getting
a 4228 through the hatch, consider the Winegard PR-8800.
Gain is a tad less than 4228, but much better than 4221
and has better multipath rejection. The PR-8800 comes
folded up, you could put it through a doggie door.
But the CM4228 is the only one that has significant gain in Hi-VHF band.

My advice would to be start by getting a better outdoor antenna with more gain rather than to try to boost the Silver Sensor. The Silver Sensor is a fine indoor UHF only antenna, but it is not really suitable for 30 miles with your color codes. Also, checking the FCC data, WJBK-DT Fox 2, currently on UHF 58, will switch to VHF 7 in February, 2009 after the analog shutdown. Oddly enough WXYZ-DT ABC 7 will stay on UHF 41. The Silver Sensor by itself will not get a VHF 7 station at that range.
Thanks for the suggestion - I was hoping to boost the Silver Sensor as it's the easiest option but 30 miles is far, I know. Also, the Silver Sensor is a bit of a kludgy solution outside. A windy day and it can get out of alignment. Interesting on the frequency switch for Fox 2 - thanks for that.

Are you interested in trying to get Toledo or other digital stations? They are 40 to 50 miles in other directions and a broad pickup antenna may be able to get some of them. For your UHF stations, the Channel Master 4221 should easily get the Detroit stations and offers a shot at getting some of the other stations in Toledo & Lansing if you can aim it just right. But the future VHF 7 at 30 miles would be iffy for a CM 4221. Is there a size constraint for the antenna on your outside mount? Maybe a CM 4220 2 Bay or CM 4221 4 Bay combined with a dipole for VHF?
Toledo or others don't interest me a bunch - I'm happy with the Detroit stations at the moment, can't see what the others would provide (but what do I know).

As for size there isn't a constraint other than visual appeal. The house basically faces the antenna (within 10 degrees) - I was thinking some mount on the chimney - otherwise I think it would look a bit ugly attached to the side of the house (chimney side). Also - the house has vinyl siding over wood siding (1938 construction).

I would prefer the CM4220 for size - but the specs say "30 miles" - I'm right on the edge of that at 32 miles so I'm not sure. I have a clear view to the east (except for some trees), I'm on a hill of sorts (as much of a hill as you can get in Michigan) so it might work.

As for size there isn't a constraint other than visual appeal. The house basically faces the antenna (within 10 degrees) - I was thinking some mount on the chimney - otherwise I think it would look a bit ugly attached to the side of the house (chimney side). Also - the house has vinyl siding over wood siding (1938 construction).

I would prefer the CM4220 for size - but the specs say "30 miles" - I'm right on the edge of that at 32 miles so I'm not sure. I have a clear view to the east (except for some trees), I'm on a hill of sorts (as much of a hill as you can get in Michigan) so it might work.
The CM 4220 2 bay is very similar to the Antennas Direct DB-2 (but cheaper). Look at the gain charts for UHF for a bunch of antennas here: http://www.hdtvprimer.com/ANTENNAS/comparing.html. The DB-2 (line L) has around 2-3 dBi gain over the Silver Sensor (line I) while the CM 4221 4 Bay (line B) offers 5-7 dBi gain over the Silver Sensor. The CM 4220 may get you a stable lock on the local stations (and is made for outdoor use), but only way to find out is to try it. If the size, weight, and harder to hide looks of the CM 4221 is not a major problem, I would get the CM 4221. I have one in my attic and it performs very well (for my situation with stations in different directions and out to 43+ miles).

Once you remove the two rear screens (via unbending tabs), the bowtie elements
are 36-in wide and 30-in high.
Hence it "should" fit through an opening that is more than 30-in on the diagonal.
If not, you'll have to drill four (or worst case eight) rivets. [Located on same piece as bendable tabs.]


Thank you for the pictures and the information! It looks like this will be the way to go then. The High-VHF response of the 4228 vs. others was interesting to find out as well. Even the 4221 suffers by comparison according to that chart.

http://www.hdtvprimer.com/ANTENNAS/comparing.html

So, unless something changes with the 2-6 assignment, perhaps this is all I would need.

Sometimes I miss having an SUV...

Thanks for the info. So, channels 2-6 are going away? I was trying to figure out exactly which channels were being auctioned and could only confirm 52-69. Channels 2-6 are so far down the ladder it makes me wonder why they are there.

I tried out analog VHF with the Silver Sensor and channels 2, 4 & 5 were predictably bad. However, some channels in the 7-13 range were halfway decent.

I found some rabbit ears, which I will try out. I may try them with a reverse splitter at first, but I'm sure a proper combiner would be better.

Channels 2-6 are not going away; however, very few stations plan to use them post-transition. For now they remain part of the DTV core. In those markets where low VHF stations will operate, OTA viewers will need rabbit ears or VHF-UHF combo antennas. One example is Harrisbburg, PA, where one station will retain its ch 4 digital channel, while the other stations in the market are (and will remain) in the UHF band.

> Sometimes I miss having an SUV...

A roof rack works well for many things. Thule, Yakama, ...

I am just getting into the world of OTA HDTV. After reading this thread, it is surprisingly much more complicated that I thought it would be! I was hoping to get some advice from you gurus.

I have a tall 2 story house in Hemby Bridge NC (approx LL 35.116306, -80.622775). I have an HDTV upstairs and one downstairs. I temporarily obtained some bunny ears (Philips MANT510) and am able to receive a handful of channels with varying degrees of success. There are about 4 stations 305 degrees 35 miles away, and another 4 stations 335 degrees 12 miles away. The best comes in nearly always with just a little hiccup if someone stands in the wrong spot of the room. The worst only occasionally gets a signal for a second or two at a time. There is nothing really between my house and the antennas, but not quite line of sight I don't think (over 30 miles there is bound to be some tall trees or houses or something).

What is my best bet on an antenna? I assume that the angle is close enough that I could point a directional at the farther stations and it would pick up the closer ones as well. How would I set it up so both TVs can use the same antenna? I currently have cheap $8 basic analog cable that I would like to keep if possible along with the antenna; could they share the same coaxial house wiring?

Thanks for your input and help! If there is more information that would help, let me know. Here is the list of channels:

Station - Frequency - Channel - Direction - Distance
CBS - 23 - 3.1 - 305 - 36.1 miles
ABC - 34 - 9.1 - 335 - 11.4 miles
FOX - 27 - 18.1 - 334 - 11.9 miles
NBC - 22 - 36.1 - 304 - 34.7 miles
PBS - 11 - 42.1 - 346 - 12.2 miles
CW - 47 - 46.1 - 306 - 34.4 miles
MNT - 39 - 55.1 - 306 - 34.4 miles
UNC - 44 - 58.1 - 9 - 16.4 miles
IND - 50 - 64.1 - 335 - 11.4 miles

I have a tall 2 story house in Hemby Bridge NC (approx LL 35.116306, -80.622775).Thanks for your input and help!

A Channel Master 4221 or Winegard DB-4 aimed at about 320 plus a VHF only aimed at 346 added together with a VHF/UHF band splitter/Joiner should get all but UNC. You may be able to split it to two TV's without an amplifer.

You can't share the cable wiring.

II have a tall 2 story house in Hemby Bridge NC (approx LL 35.116306, -80.622775). I have an HDTV upstairs and one downstairs. I temporarily obtained some bunny ears (Philips MANT510) and am able to receive a handful of channels with varying degrees of success. There are about 4 stations 305 degrees 35 miles away, and another 4 stations 335 degrees 12 miles away.
I also vote for the Channel Master 4221 4 Bay bowtie mounted up in the attic or outside. The CM 4221 has a broad pickup pattern to the front, so it should be fine for stations 30 degrees apart. (see http://www.hdtvprimer.com/ANTENNAS/cm4221.html). You have one digital station, WTVI-DT PBS 42 broadcasting on VHF 11, but it is 12.5 miles with a yellow color code. The CM 4221 is a UHF antenna, but has some modest gain for the very upper end of VHF, say 11 to 13. It is likely to get the WTVI-DT PBS station ok. If not, you can add a simple rabbit ear antenna with a UHF/VHF antenna combiner.

As for sharing co-axial cable, you can not share an OTA antenna with the signals coming from the cable TV company on the same co-axial cable. Broadcast TV and cable TV use many of the same frequencies. You will have to run a separate RG-6 co-axial line from the antenna to the TVs. Try it without a pre-amp first. 35 miles in your country is really too far to expect an indoor antenna to work near the TV. You need to get the antenna up in the attic or outdoors for increased height and to get it away from people walking around the antenna.

Out of the box, the rear screens on my CM-4228 are 39.5-in wide and 36-in high.

Once you remove the two rear screens (via unbending tabs), the bowtie elements
are 36-in wide and 30-in high.
Hence it "should" fit through an opening that is more than 30-in on the diagonal.
If not, you'll have to drill four (or worst case eight) rivets. [Located on same piece as bendable tabs.]

The 39x41x5.5-in box fits rear hatch of Volvo Stn Wagon, but NOT via rear passenger door....YMMV...


To my surprise, I was able to fit the box in the trunk of my car, at least width-wise. I had to tie down the trunk as it wouldn't close, but getting it out of the Fry's store was harder. The box is certainly unwieldy and navigating through narrow aisles when people aren't paying attention was a bunch of fun.

Everything after that wasn't bad at all. I did have to detach the screens and re-attach them, but it was easy to do. Thank you again for letting me know about that trick!

It's in the attic on a mast that I put up along one of the vertical rafters, which wasn't as straight as I thought. If I got it to work right, attached is an image of my installation.

How does it work? Very well in that spot and I'm very pleased with its performance. All the stations that I would get before are at 100% except for 1 at 99% and another at 87%. The two tough local stations to get are now coming in fine. I'm still using the CM3043 distribution amp. as it made a very big difference before I put the antenna into the attic. I think I will leave it in place since I'm driving 2 TV's.

One question I have is whether I should use a grounding wire. Since it's in the attic, I don't have to worry about the elements, but perhaps it would be a good idea if I can find anything nearby to ground it with.

Thanks again for helping make this possible!

There is no NEC requirement to use a grounding wire indoors.

Attic installations are tricky, trying to find a good line of sight to the towers with
a minimum of intervening "stuff"....and reflections from nailing plates, wires, etc....

If you have any more problems, it's worth it to try several different locations.

Maybe a dumb idea, but I'm just thinking... As of 2/2009 the Cincinnati market will have only 2 VHF channels, transmitting from about 5 degrees apart on Channels 10 and 12. I've got a CM4228 on a rotator now which picks up broadcast Ch. 10 fine, but I just wondered: Would producing a monster single channel 11 antenna in the attic with about 16 feet of length and 1/2" pipe for elements combine well with a VHF/UHF combiner and pull in the hi-VHF channels from that direction for sure? If "more is better, too much is just right" affecting my thinking here? I'm also not web-savvy enough to locate some of those posts where folks made DIY non-weathproof antenna out of curtain rods, etc. Anyone point me to the sites where they would tell you the element length and spacing for a DIY job? Or is this doomed to fail? Thanks.

Maybe a dumb idea, but I'm just thinking... As of 2/2009 the Cincinnati market will have only 2 VHF channels, transmitting from about 5 degrees apart on Channels 10 and 12. I've got a CM4228 on a rotator now which picks up broadcast Ch. 10 fine, but I just wondered: Would producing a monster single channel 11 antenna in the attic with about 16 feet of length and 1/2" pipe for elements combine well with a VHF/UHF combiner and pull in the hi-VHF channels from that direction for sure? If "more is better, too much is just right" affecting my thinking here? I'm also not web-savvy enough to locate some of those posts where folks made DIY non-weathproof antenna out of curtain rods, etc. Anyone point me to the sites where they would tell you the element length and spacing for a DIY job? Or is this doomed to fail? Thanks.


GO to above on page 194 post #5803 or just click here it will take you there
http://www.avsforum.com/avs-vb/showthread.php?p=10580435&&#post10580435 read that post and read post #5807 and don't let Rick0725 scare you, I think he just jealous that my antenna works for me and his didn't :D

At http://www.lumenlab.com/forums/index.php?showtopic=9613 there is 38 pages long but I use the first one and made few mods and it works great for me. There is other desgins on that website, just go look though all of them. I did pick up a 1MW DT 51 that is 73 miles away with no problem also. I am also using Channel Master pre-amp 7777 in the setup. I am going to try the new Channel Master 4220 desgin someday and see how that one will works the bow is longer and wider V than DB-2 antenna.

Good luck on building your own DIY antenna.

-Willie

.. As of 2/2009 the Cincinnati market will have only 2 VHF channels, transmitting from about 5 degrees apart on Channels 10 and 12. .

These should work fine on both 10 and 12:

http://www.solidsignal.com/prod_display.asp?PROD=Y5-7-13
http://www.warrenelectronics.com/antennas/y10713.htm

Modern broadband TV antenna designs use computers to vary the element
lengths and spacings in order to search through a large number of "de-tuned"
antenna designs until they stumble across a "good enough" design that
more or less optimizes gain across the entire design bandwidth:
http://ic.arc.nasa.gov/people/jlohn/Papers/ices2001.pdf

Hence, it would be difficult for you to build a multi-channel Yagi antenna.
The above recommendations are very good for $20-50....

============================
But, if you just must DIY, Single Channel Yagi info is found here:
http://www.skyscan.ca/Antennas.htm
http://www.ifwtech.co.uk/g3sek/diy-yagi/
http://www.k7mem.150m.xxx/Electronic_Notebook/antennas/yagi_vhf.html
[For some reason forum won't accept this webite. Replace "xxx" with "com"]
Note that Ham Radio boom designs are matched to 50-ohm transmitters....close enough???

However, in the VHF band, the bandwidth in a moderate to high gain Single Channel
Yagi may not even cover CH11, and the severe slope in frequency response
through CH10 and CH12 could cause problems:
http://www.cebik.com/vhf/scales.html

============================
An LPDA (Log Periodic Dipole Array) would be a more feasible multi-channel DIY project.
It provides more or less constant gain across all channels, at the expense
of maximum gain on a single channel.

DIY LPDA info is found here:
http://www.wb0dgf.com/
http://www.physics.adelaide.edu.au/~dmcintos/docs/Log-Periodic.pdf
http://www.qrz.com/download/antennas/index.html
The lowest and highest design frequencies for the LPDA should be about 20 percent
lower and higher than the desired reception frequencies.

See LPDA Spread Sheet Calculator below (from QRZ) for an example Hi-VHF Band design.

Here is more info re DIY Folded Dipole....which becomes a Yagi with Reflector and (optional) Director:
http://www.wfu.edu/~matthews/misc/dipole.html

Note the "DIY" (search thread) subject has been discussed several times before:
http://www.avsforum.com/avs-vb/showthread.php?p=6313277&highlight=diy#post6313277

I have a problem that I'm sure has been addressed somewhere in this thread, but in the intrest of time I will ask again. I live in the Wilmington, NC area with the closest broadcast tower (ABC) about 7.3 miles away from my home and the furthest being about 16.8 miles away (NBC & PBS from the same tower). After discovering that I could recieve OTA HD I decided that I would give a set top antenna a shot. With the set top antenna I was able to pull in all of my local stations with good signal strength (60-70%) except for NBC. I was confused why I could recieve PBS, but not NBC because they are both brodcast from the same tower. I soon learned that PBS broadcasts from a higher elevation on the tower. After doing some reading I decided that I would give the Radio Shack U-75R outdoor antenna a shot (only $30). So I ran about 100' of RG6 up to the attic and attached the antenna to a mast high in the top of my attic. Wow, now I get NBC @ 85%, FOX @ 95%, and PBS at 100% with all of them being rock solid stable. Now I'm having trouble staying locked on ABC! The signal for ABC jumps around from 0-75+%. It's really annoying because the picture keeps pixelating. Since I'm only about 7.3 miles from their tower I think what I am experiencing is multipath. Does this sound like multipath? If so, is there any way around this or am I just going to have to decide which channel I want the most, ABC with the indoor antenna or NBC with the attic antenna? Do you think a non-yagi antenna like the Eagle Aspen DTV2BUHF two bay antenna would work better to reduce multipath, or is a yagi best in this situation? I really like the attic antenna setup because I don't have to look at the UHF loop in my living room. ANY HELP WILL BE GREATLY APPRECIATED!!! I'm almost ready to pull my hair out here. Thanks.

Try moving the antenna up and down on the mast and if that doesn't work, try different locations.

I have a problem that I'm sure has been addressed somewhere in this thread, but in the intrest of time I will ask again. I live in the Wilmington, NC area with the closest broadcast tower (ABC) about 7.3 miles away from my home and the furthest being about 16.8 miles away (NBC & PBS from the same tower). After discovering that I could recieve OTA HD I decided that I would give a set top antenna a shot. With the set top antenna I was able to pull in all of my local stations with good signal strength (60-70%) except for NBC. I was confused why I could recieve PBS, but not NBC because they are both brodcast from the same tower. I soon learned that PBS broadcasts from a higher elevation on the tower. After doing some reading I decided that I would give the Radio Shack U-75R outdoor antenna a shot (only $30). So I ran about 100' of RG6 up to the attic and attached the antenna to a mast high in the top of my attic. Wow, now I get NBC @ 85%, FOX @ 95%, and PBS at 100% with all of them being rock solid stable. Now I'm having trouble staying locked on ABC! The signal for ABC jumps around from 0-75+%. It's really annoying because the picture keeps pixelating. Since I'm only about 7.3 miles from their tower I think what I am experiencing is multipath. Does this sound like multipath? If so, is there any way around this or am I just going to have to decide which channel I want the most, ABC with the indoor antenna or NBC with the attic antenna? Do you think a non-yagi antenna like the Eagle Aspen DTV2BUHF two bay antenna would work better to reduce multipath, or is a yagi best in this situation? I really like the attic antenna setup because I don't have to look at the UHF loop in my living room. ANY HELP WILL BE GREATLY APPRECIATED!!! I'm almost ready to pull my hair out here. Thanks.
Your zip code PLEASE!!!! We need to look your stations up by call letter (just ABC does not tell us very much of use). How far apart in azimuth are your ABC and NBC & PBS stations? The Radio Shack U-75R yagi is a directional antenna and is VERY touchy for finding the right aim. I had one and dumped it in favor of a Channel Master 4221 4 Bay because I wanted to get digital UHF stations over a wide spread in azimuth.

Your zip code PLEASE!!!! We need to look your stations up by call letter (just ABC does not tell us very much of use). How far apart in azimuth are your ABC and NBC & PBS stations? The Radio Shack U-75R yagi is a directional antenna and is VERY touchy for finding the right aim. I had one and dumped it in favor of a Channel Master 4221 4 Bay because I wanted to get digital UHF stations over a wide spread in azimuth.

Sorry, I forgot to give that information. My zip code is 28479. Thanks for the help.

Sorry, I forgot to give that information. My zip code is 28479. Thanks for the help.
The edited antennaweb results for your zip code for your local digital stations:

* yellow - uhf WECT-DT 6.1 NBC WILMINGTON NC 334° 16.8 44
* yellow - uhf WUNJ-DT 39.1 PBS WILMINGTON NC 334° 16.8 29
* yellow - uhf WWAY-DT 3.1 ABC WILMINGTON NC 284° 7.3 46
* yellow - uhf WSFX-DT 26.1 FOX WILMINGTON NC 56° 10.7 30
* red - uhf WPXU-DT 35.1 MNT JACKSONVILLE NC 60° 44.6 34

You have a 50 degree spread in azimuth between the WECT-DT NBC and WWAY-DT ABC. No wonder the very directional Radio Shack U-75R can't get them. The Fox station is probably coming in a weak sidelobe. Looking deeper at the antennaweb results, your local CBS station is WILM-LP 10 which is a low power analog only station which presumably won't go digital until 2009. Your nearest digital CBS station is WBTW-DT CBS 13 (DT=56) at ~ 74 miles away in Florence, SC. Do you have any interest in trying to get this station as it would require a deep fringe antenna up on the roof, but with no guarantee of success?

My recommendation that for your local stations, you get the Channel Master 4221 4 Bay bowtie. You will have to experiment with the aim, but it offers a good shot at getting all of your locals. It may also pick up the WPXU-DT My Network station in Jacksonville.

The edited antennaweb results for your zip code for your local digital stations:

* yellow - uhf WECT-DT 6.1 NBC WILMINGTON NC 334° 16.8 44
* yellow - uhf WUNJ-DT 39.1 PBS WILMINGTON NC 334° 16.8 29
* yellow - uhf WWAY-DT 3.1 ABC WILMINGTON NC 284° 7.3 46
* yellow - uhf WSFX-DT 26.1 FOX WILMINGTON NC 56° 10.7 30
* red - uhf WPXU-DT 35.1 MNT JACKSONVILLE NC 60° 44.6 34

You have a 50 degree spread in azimuth between the WECT-DT NBC and WWAY-DT ABC. No wonder the very directional Radio Shack U-75R can't get them. The Fox station is probably coming in a weak sidelobe. Looking deeper at the antennaweb results, your local CBS station is WILM-LP 10 which is a low power analog only station which presumably won't go digital until 2009. Your nearest digital CBS station is WBTW-DT CBS 13 (DT=56) at ~ 74 miles away in Florence, SC. Do you have any interest in trying to get this station as it would require a deep fringe antenna up on the roof, but with no guarantee of success?

My recommendation that for your local stations, you get the Channel Master 4221 4 Bay bowtie. You will have to experiment with the aim, but it offers a good shot at getting all of your locals. It may also pick up the WPXU-DT My Network station in Jacksonville.

I'm not really all that intrested in recieving CBS because I'm don't want to install a rooftop antenna. ABC, NBC, and FOX are all I really want to watch anyways. Like I said before, the Radio Shack U-75R is pulling in all the stations (except CBS of course), I'm just trying to combat multipath from WWAY-DT ABC. Do you think a 2 or 4 bay bowtie antenna would eliminate the multipath? Once again, thanks for the help.

just recently tried to tame a few multipath issues.

started with the eagle 2 bay...that didnt work...then a cm4221....that didnt work...then a u75 that didnt work. it was good better best as mentioned. ended up using a 43xg.

from my experiences, the bowties tame multipath poorly so would avoid them for now. what I would try first before you buy anything is see if you can get a stable lock on your problem station by experimenting with aim. do not worry about what happens to the good stations. you just want to see if an antenna will get a decent lock aimed in the right direction. this way you can narrow down some of the causes. then we will go from there. your issue may not be multipath but a poor signal. this will be a way to find out.

are you amplifying?

I'm not really all that intrested in recieving CBS because I'm don't want to install a rooftop antenna. ABC, NBC, and FOX are all I really want to watch anyways. Like I said before, the Radio Shack U-75R is pulling in all the stations (except CBS of course), I'm just trying to combat multipath from WWAY-DT ABC. Do you think a 2 or 4 bay bowtie antenna would eliminate the multipath? Once again, thanks for the help.
Your problem is probably not multipath. You are using a highly directional antenna while you have stations at 284°, 334°, and 56°. You need a multi-directional or omni-directional antenna. Did your set top antenna that you were originally using have a UHF loop antenna (this would be a loop about 7.5" in diameter)? The UHF loop has a very broad gain pattern (see http://www.hdtvprimer.com/ANTENNAS/Loop.html).

Your problem is probably not multipath. You are using a highly directional antenna while you have stations at 284°, 334°, and 56°. You need a multi-directional or omni-directional antenna. Did your set top antenna that you were originally using have a UHF loop antenna (this would be a loop about 7.5" in diameter)? The UHF loop has a very broad gain pattern (see http://www.hdtvprimer.com/ANTENNAS/Loop.html).

The set top antenna that I was using was a non amplified UHF loop. When I used it in the living room I was able to stay locked on WWAY-DT with no drop out or pixelation and maintained about 65% signal strength. I took the UHF loop up to the attic and put it on the line that I ran for the U-75r and it drops out and pixelates the same way the U-75r does, but with lower reception strenghts.

In answer to the previous post, no I am not amplifying the signal. I didnt think that it was neccesary because most of my stations come in at 75+% including WWAY-DT when it grabs the signal.

I'm about to replace my Terk TV55 HD antenna thats mounted in my attic. I got good signal strength (95-98) but it "died" tonight during bad weather (nothing hit remotely close). I'm considering the CM 4220 for a replacement (attic mount). My station stastics are:


* yellow - uhf WDSU-DT 6.1 NBC NEW ORLEANS LA 207° 22.1 43
* yellow - uhf WGNO-DT 26.1 ABC NEW ORLEANS LA 209° 19.8 15
* yellow - uhf WLAE-DT 31 PBS NEW ORLEANS LA FCC Ext 209° 19.9 31
* yellow - vhf WYES-DT 12.1 PBS NEW ORLEANS LA 206° 21.6 11
* yellow - uhf WVUE-DT 8.1 FOX NEW ORLEANS LA 206° 21.6 29
* yellow - uhf WNOL-DT 38.1 CW NEW ORLEANS LA 209° 19.8 40
* red - uhf WUPL-DT 54.1 MNT SLIDELL LA 297° 8.0 24
* red - uhf WWL-DT 4.1 CBS NEW ORLEANS LA 213° 7.2 36
* red - uhf WPXL-DT 26.1 ION NEW ORLEANS LA 213° 25.8 50
* violet - uhf WHNO-DT 20.1 IND NEW ORLEANS LA 213° 25.8 21


All of the stations are 25.8 miles or less from me and are within 206 to 213 degrees, a 7 degree spread, except for WUPL-DT which we never watch. Aiming at 210 degrees gave me a strong signal with the Terk TV55 bafore it croaked.

Based on the above, would the CM4220 or CM4221 pick up WYES-DT 12.1 which has a VHF frequency assignment of channel 11? Also, what kind of performance should I expect from these antennas? Thanks for reply(s).

Reception Range cm4220
Channels 7 thru 13 - Up to 20 miles
Channels 14 thur 69 - Up to 30 miles

based on mfg's specs above (up to 20 miles for ch 7-13) the cm4220 would most likely be marginal/risky at your home.

I would therefore suggest something different in your case.

I'm about to replace my Terk TV55 HD antenna thats mounted in my attic. I got good signal strength (95-98) but it "died" tonight during bad weather (nothing hit remotely close). I'm considering the CM 4220 for a replacement (attic mount). My station stastics are:
[snip]
All of the stations are 25.8 miles or less from me and are within 206 to 213 degrees, a 7 degree spread, except for WUPL-DT which we never watch. Aiming at 210 degrees gave me a strong signal with the Terk TV55 bafore it croaked.

Based on the above, would the CM4220 pick up WYES-DT 12.1 which has a VHF frequency assignment of channel 11? Also, what kind of performance should I expect from this antenna? Thanks for reply(s).
WYES-DT PBS 12 is listed to be at 70.8 kW on VHF 11, so it is at a respectable power level for digital upper VHF. If you have room in the attic, I suggest you get the CM 4221 4 Bay bowtie instead. Has more gain than the CM 4220 and should bring the station on VHF 11, assuming no nearby obstructions. If you play with the aim of either CM antenna a bit by aiming it either south of the 209° to 213° group of stations to put the My Network station in the back lobe or north of the group to put it in the sidelobe, you can probably get that station as well (WUPL-DT has an authorized power of 1000 kW for UHF 24), even though it is not important to you. But you might as well as get all your local digital stations.

I'm about to replace my Terk TV55 HD antenna thats mounted in my attic. I got good signal strength (95-98) but it "died" tonight during bad weather (nothing hit remotely close). I'm considering the CM 4220 for a replacement (attic mount). My station stastics are:


* yellow - uhf WDSU-DT 6.1 NBC NEW ORLEANS LA 207° 22.1 43
* yellow - uhf WGNO-DT 26.1 ABC NEW ORLEANS LA 209° 19.8 15
* yellow - uhf WLAE-DT 31 PBS NEW ORLEANS LA FCC Ext 209° 19.9 31
* yellow - vhf WYES-DT 12.1 PBS NEW ORLEANS LA 206° 21.6 11
* yellow - uhf WVUE-DT 8.1 FOX NEW ORLEANS LA 206° 21.6 29
* yellow - uhf WNOL-DT 38.1 CW NEW ORLEANS LA 209° 19.8 40
* red - uhf WUPL-DT 54.1 MNT SLIDELL LA 297° 8.0 24
* red - uhf WWL-DT 4.1 CBS NEW ORLEANS LA 213° 7.2 36
* red - uhf WPXL-DT 26.1 ION NEW ORLEANS LA 213° 25.8 50
* violet - uhf WHNO-DT 20.1 IND NEW ORLEANS LA 213° 25.8 21


All of the stations are 25.8 miles or less from me and are within 206 to 213 degrees, a 7 degree spread, except for WUPL-DT which we never watch. Aiming at 210 degrees gave me a strong signal with the Terk TV55 bafore it croaked.

Based on the above, would the CM4220 pick up WYES-DT 12.1 which has a VHF frequency assignment of channel 11? Also, what kind of performance should I expect from this antenna? Thanks for
reply(s).

You will get everything with no problem in your location with a CM4220. WYES has a strong signal and you'll easily have 100%. I live in Huntwyck by the mall and get 100% on WYES. I don't have a CM4220, but I have a similiar outdoor that I bought from Circuit City.

I don't have a CM4220, but I have a similiar outdoor that I bought from Circuit City.

can you share with us which antenna you have that is successful for you. it would be a good opportunity for the user in question.

I'm about to replace my Terk TV55 HD antenna thats mounted in my attic. I got good signal strength (95-98) but it "died" tonight during bad weather (nothing hit remotely close). I'm considering the CM 4220 for a replacement (attic mount). My station stastics are:


* yellow - uhf WDSU-DT 6.1 NBC NEW ORLEANS LA 207° 22.1 43
* yellow - uhf WGNO-DT 26.1 ABC NEW ORLEANS LA 209° 19.8 15
* yellow - uhf WLAE-DT 31 PBS NEW ORLEANS LA FCC Ext 209° 19.9 31
* yellow - vhf WYES-DT 12.1 PBS NEW ORLEANS LA 206° 21.6 11
* yellow - uhf WVUE-DT 8.1 FOX NEW ORLEANS LA 206° 21.6 29
* yellow - uhf WNOL-DT 38.1 CW NEW ORLEANS LA 209° 19.8 40
* red - uhf WUPL-DT 54.1 MNT SLIDELL LA 297° 8.0 24
* red - uhf WWL-DT 4.1 CBS NEW ORLEANS LA 213° 7.2 36
* red - uhf WPXL-DT 26.1 ION NEW ORLEANS LA 213° 25.8 50
* violet - uhf WHNO-DT 20.1 IND NEW ORLEANS LA 213° 25.8 21


All of the stations are 25.8 miles or less from me and are within 206 to 213 degrees, a 7 degree spread, except for WUPL-DT which we never watch. Aiming at 210 degrees gave me a strong signal with the Terk TV55 bafore it croaked.

Based on the above, would the CM4220 or CM4221 pick up WYES-DT 12.1 which has a VHF frequency assignment of channel 11? Also, what kind of performance should I expect from these antennas? Thanks for reply(s).


I have a Homebuilt DB-2 antenna and I can get Fox 47 on DT 11 with no problem that is 57 miles away. So go for it the CM 4220. I also have a PBS 10 on DT 8 that 43 miles away and lock on good with NO BREAK-UPs.

-Willie

can you share with us which antenna you have that is successful for you. it would be a good opportunity for the user in question.


Just look up at CC and I don't see XG-91 antenna so it won't be that one. Bummer

I'm currently using a RS VU-90 XR antenna for HDTV and FM and there is about 8' of coax before the split point. The first TV/FM location is at the split point and there is another 8' to the second split.

I was splitting the signal with a Monster 3 way splitter with outputs to a TV and FM in one location and the third output to another location. This third output was then split again with a 2 way splitter to a HDTV PCI card and an FM tuner. This caused a some channel loss and drop outs; so I replaced the Monster 3 way with a 2 way to just the HDTV and HDTV PCI card and the HDTV all our OTA channels are fairly steady on both.

All the signals - TV and FM come from the same direction and are about 30 miles away.

I would like to use an outdoor antenna for the FM; so what would be the preferred option:

1. A second dedicated FM antenna which I used to use before we went HDTV. I can't do much with the antenna mounting; so I may not have sufficient space on the pole for antenna spacing.

2. Some kind of pre-amp (Hi gain or low gain).

3. A distribution amp.

TIA,

Wayne

the vu90 has a huge gain dip on fm below 95 mhz so a separate fm antenna is a good idea.

http://www.hdtvprimer.com/ANTENNAS/comparing.html

adding a separate fm antenna is best. there are several options. the fm-6 and hd6065p are good performers. It is best not to amplify fm. the hd 6065p is pretty nice. of course there are bigger and better choices.

http://www.starkelectronic.com/fm.htm

instead of using a standard splitter use a winegard ca 8800 fm/tv splitter combiner. the losses are much less. the ca 8800 has only .4 db insertion loss instead of 3.5 db of a standard 2 way splitter.

http://www.summitsource.com/winegard-ca8800-tv-antenna-signal-band-separator-video-vhf-uhf-fm-75-ohm-coaxial-cable-with-f-connector-plugs-coupler-combiner-ac-passive-part-ca8800-p-5703.html

you can at the same time take the opportunity to replace the uv90 antenna if you want to take the opportunity to upgrade . if all your channels are uhf, the 91xg would stack nicely with the fm antenna. if you desire uhf/vhf suggest the winegard hd7082p or hd7084p (if you have reception challenges...next size up) for 30 miles. the hd7082p and hd7084p work well with fm. the smaller 7080p not good.

http://www.summitsource.com/winegard-hd7082p-platinum-hd-tv-antenna-hd7082-vhf-uhf-hdtv-50-element-offair-local-channel-signal-digital-outdoor-television-aerial-75-ohm-blue-zone-part-hd7082-with-coax-cable-p-4563.html

I'm about to replace my Terk TV55 HD antenna thats mounted in my attic. I got good signal strength (95-98) but it "died" tonight during bad weather (nothing hit remotely close). I'm considering the CM 4220 for a replacement (attic mount). My station stastics are:

* yellow - uhf WDSU-DT 6.1 NBC NEW ORLEANS LA 207° 22.1 43
* yellow - uhf WGNO-DT 26.1 ABC NEW ORLEANS LA 209° 19.8 15
* yellow - uhf WLAE-DT 31 PBS NEW ORLEANS LA FCC Ext 209° 19.9 31
* yellow - vhf WYES-DT 12.1 PBS NEW ORLEANS LA 206° 21.6 11
* yellow - uhf WVUE-DT 8.1 FOX NEW ORLEANS LA 206° 21.6 29
* yellow - uhf WNOL-DT 38.1 CW NEW ORLEANS LA 209° 19.8 40
* red - uhf WUPL-DT 54.1 MNT SLIDELL LA 297° 8.0 24
* red - uhf WWL-DT 4.1 CBS NEW ORLEANS LA 213° 7.2 36
* red - uhf WPXL-DT 26.1 ION NEW ORLEANS LA 213° 25.8 50
* violet - uhf WHNO-DT 20.1 IND NEW ORLEANS LA 213° 25.8 21

All of the stations are 25.8 miles or less from me and are within 206 to 213 degrees, a 7 degree spread, except for WUPL-DT which we never watch. Aiming at 210 degrees gave me a strong signal with the Terk TV55 bafore it croaked.

Based on the above, would the CM4220 or CM4221 pick up WYES-DT 12.1 which has a VHF frequency assignment of channel 11? Also, what kind of performance should I expect from these antennas? Thanks for reply(s).
Just wanted to update. I purchased a CM4221 mainly based on what I read here......THANKS! Last night, I got it installed in the attic where the Terk was for three years. With no amp, in the Oak Harbor area of south Slidell (very few tall trees), I'm getting a consistant 98 on my signal meter on all N.O. HD stations currently on the air. With the Terk, I used to get Biloxi and one Baton Rouge station but no more......but thats OK! I didn't watch them anyway. :cool: Needless to say, I'm thrilled the problem was the dead Terk and not my brand new 70"XBR2! Now we can throw away the Sony box thats taking up half of my garage. :D

curious

how is ch 11 being received with the cm4221 and how does signal strength compare with the other uhf channels.

please give examples.

curious

how is ch 11 being received with the cm4221 and how does signal strength compare with the other uhf channels.

please give examples.
Channel 11 (WYES-HD 12.1) is also coming in with a consistant signal 98 (as are all the rest)

Examples:

Physical Channel: 11
Frequency KHz: 201000
Modulation: 8VSB
Status: LOCK
Errors: 0
SNR (db): 32
AGC (%): 34

I'm 21.6 miles from the Ch.11 transmitter and I have the antenna aimed @ 210 to cover the spread (206-213). The CM4221 and CM4228 are known to give good results on the upper VHF digital band as well as UHF. :)

Channel 11 (WYES-HD 12.1) is also coming in with a consistant signal 98 (as are all the rest)

Examples:

Physical Channel: 11
Frequency KHz: 201000
Modulation: 8VSB
Status: LOCK
Errors: 0
SNR (db): 32
AGC (%): 34

I'm 21.6 miles from the Ch.11 transmitter and I have the antenna aimed @ 210 to cover the spread (206-213). The CM4221 and CM4228 are known to give good results on the upper VHF band as well as UHF. :)


With WYES at 70.8 Kw You could of gotten away with a 4220. As I can pickup DT-8 at 25 Kw at 43 miles away and DT-11 at 15 Kw at 57 miles away with a homebuilt DB-2.

With WYES at 70.8 Kw You could of gotten away with a 4220. As I can pickup DT-8 at 25 Kw at 43 miles away and DT-11 at 15 Kw at 57 miles away with a homebuilt DB-2.
Why get away with $5 difference in price between the 4220 and 4221. :rolleyes: I didn't want to take the chance. I've got all the locals pegged @98 signal strength............good enough for me. Thanks.

the vu90 has a huge gain dip on fm below 95 mhz so a separate fm antenna is a good idea.

http://www.hdtvprimer.com/ANTENNAS/comparing.html

adding a separate fm antenna is best. there are several options. the fm-6 and hd6065p are good performers. It is best not to amplify fm. the hd 6065p is pretty nice. of course there are bigger and better choices.

http://www.starkelectronic.com/fm.htm

instead of using a standard splitter use a winegard ca 8800 fm/tv splitter combiner. the losses are much less. the ca 8800 has only .4 db insertion loss instead of 3.5 db of a standard 2 way splitter.

http://www.summitsource.com/winegard-ca8800-tv-antenna-signal-band-separator-video-vhf-uhf-fm-75-ohm-coaxial-cable-with-f-connector-plugs-coupler-combiner-ac-passive-part-ca8800-p-5703.html

you can at the same time take the opportunity to replace the uv90 antenna if you want to take the opportunity to upgrade . if all your channels are uhf, the 91xg would stack nicely with the fm antenna. if you desire uhf/vhf suggest the winegard hd7082p or hd7084p (if you have reception challenges...next size up) for 30 miles. the hd7082p and hd7084p work well with fm. the smaller 7080p not good.

http://www.summitsource.com/winegard-hd7082p-platinum-hd-tv-antenna-hd7082-vhf-uhf-hdtv-50-element-offair-local-channel-signal-digital-outdoor-television-aerial-75-ohm-blue-zone-part-hd7082-with-coax-cable-p-4563.html

Rich,

Thanx for the links. I'm not even considering replacing our antenna until analog cut-off and channel shifting is sorted out. The FM situation is interesting in that my antenna, according to one of the links, has the greatest drop off in the higher FM frequencies but I'm interested in the lower frequencies, especially the public broadcasting frequencies.

I think I will try one of the Winegard splitters though before I opt for any other upgrades - amplifier/pre-amplifier or different antenna configuration.

Our local OTA is currently split evenly between VHF and UHF and it is my understaning that there isn't going to be much difference when analog shuts off. The VHF/UHF line up may be somewhat different but there will still be VHF and UHF broadcasters.

Wayne

Sorry for the newbie question, but can cable internet service and the signal from my OTA antenna coexist on the same RG-6 going throughout my house? (Ordinary splitters to combine and then split out between the computer and TV area?) I understand that regular cable TV and OTA can't share the same cable.

Not a good idea.

Whatever signals remain on the cable coax (probably most digital QAM channels
plus the cable modem freq) will leak out of your antenna (an FCC violation).

Even if they employ "tier filters" to pass ONLY the cable modem frequency,
the residual noise on the cable coax could still degrade your OTA reception....

Anyone else have problems with CM Jointennas being bad out of the box? I bought three, two work fine, one doesn't pass it's tuned channel through its bandpass filter without knocking its level down a lot. Are there any alternatives to these devices? If they're going to be faulty or mistuned (after waiting a month to arrive), I'd like to consider other options... preferably something I can tune myself.

There are losses using jointennas...........
I have a CM4221......works great! What's a jointenna? :confused:

I have a CM4221......works great! What's a jointenna? :confused:

It's a two-input combiner with a band pass filter on one input and a band stop filter on the other.

The typical use for it is that if you have two antennas, one pointed at several TV transmitters, and the other pointed in another direction at a lone transmitter, you can combine the two antenna signals without the two antennas' signals interferring with each other. (It's rare that you can successfully take two antennas and connect their signals with a simple combiner.)

You order the Jointenna tuned for a specific channel number, the channel of the lone transmitter. You then hook that lone antenna's signal into the bandpass filter input, and ONLY that one channel's signal is passed on to the internal combiner. You hook the other antenna's signal into the band stop filter, and every signal from that antenna EXCEPT the specified channel is passed on to the internal combiner.

If the Jointenna is working properly, the signals that are intentionally passed through from either input are not attenuated very much. In my case, a non-specified channel's signal coming into the band stop input dropped from a reading of 70 on my TV's meter to 67....a nominal amount. The specified channel's signal coming into the band pass filter dropped from a reading of 73 to a value in the low 40s, making it useless on its own. I scrounged up an amp to give a preliminary boost to the specified channel's antenna, and that got the signal to come through at about a value of 57 on my TV, but that's a kludge that shouldn't be needed. I have two other Jointennas, and their specified channels tend to pass signal through with only a drop of about 3, like I'd expect.

So the unit in question is either outright faulty, or (I'm guessing more likely) not tuned properly. And that's what p@@@@@ me off , er, uh, bothers me. When you order a Jointenna, you have to wait several weeks for it to be custom tuned. If they're not going to tune it any better than this, I'd rather do it myself.

Open question to all: Have any of you tuned a Jointenna yourself? Is it worth trying on my own, or are the adjustments too quirky to try?

Tobias, thanks for that comprehensive explanation. I had no clue as to what a jointenna was. I'm now informed. Thanks again and I hope you get your problem worked out.

I'm in zip 95618, about 22 miles LOS from most of the stations of interest. I recently picked up a Samsung 260F HD STB and connected it to my rooftop antenna (similar to the winegard-hd7010 or Channel Master 3016)

This antenna gave quite good VHF/UHF NTSC reception. For HD OTA I get 80-100% for most stations, however both Fox and PBS (both lower power than the rest) tend to come in ok after dark, but have dropouts with 0-50% signal strength during daylight.

Question: do I need a better antenna (suggestions?), or would a preamp help more? I did take the single splitter out for now and this improved Fox/PBS (generally up to 80% most of the time, but still some 1-4 second drop outs now and then, but much less frequently). Another point might be wind/trees; there are several redwoods (ca 30' high) about 30' from the antenna, but they're kinda thin and you can generally see thru them.

My cable length is about 75' to the STB (25' to the splitter)

thanks for any suggestions

how old is your coax and is it RG6 or better ?

for giggles, try a straight run of coax, replace the splitter with a double female "F" barrel connector, and see if the two stations improve during the day. A splitter means a 3db loss (about 50%) in signal to each TV and can seriously degrade the received signal for the two lower power stations

how old is your coax and is it RG6 or better ?

it's less than a year old, and it's RG6...all pretty new after my roof was done 18 months ago. My previous antenna got trashed, and this one was around so I put it up -- I think it's an old radio shack that was sitting in the attic (it hasn't been exposed much).

for giggles, try a straight run of coax, replace the splitter with a double female "F" barrel connector,


I did do this (that's what I was trying to say in the 3rd paragraph); it did get better, but still needs some more improvement. I'm trying to figure out whether a preamp or larger antenna would work better (or maybe something else?)

thanks!

You're clearly right on the margin with those stations; if removing the splitter helps, either a pre-amp or a larger antenna will help. The pre-amp is probably easier to install.

I'm in zip 95618, about 22 miles LOS from most of the stations of interest. I recently picked up a Samsung 260F HD STB and connected it to my rooftop antenna (similar to the winegard-hd7010 or Channel Master 3016)

This antenna gave quite good VHF/UHF NTSC reception. For HD OTA I get 80-100% for most stations, however both Fox and PBS (both lower power than the rest) tend to come in ok after dark, but have dropouts with 0-50% signal strength during daylight.

Question: do I need a better antenna (suggestions?), or would a preamp help more? I did take the single splitter out for now and this improved Fox/PBS (generally up to 80% most of the time, but still some 1-4 second drop outs now and then, but much less frequently). Another point might be wind/trees; there are several redwoods (ca 30' high) about 30' from the antenna, but they're kinda thin and you can generally see thru them.

My cable length is about 75' to the STB (25' to the splitter)

thanks for any suggestions
A mast mounted (even if only at the bottom) Preamp will provide a big improvement,
and no worries about overload from nearby stations.

Looks like all of your dtv stations will stay in UHF after analog shutdown in 2009. also, according to FCC map you are well within the coverage area of Fox - KTXL, (http://www.fcc.gov/fcc-bin/FMTV-service-area?x=DT1018506.html), and Pbs - CAVIE (http://www.fcc.gov/fcc-bin/FMTV-service-area?x=DS658432.html). I would swap your antenna for a Channel Master 4228, cost $50-60 plus ship. Save the added (small) cost of electricity powering amp 24/7.

Looks like all of your dtv stations will stay in UHF after analog shutdown in 2009. also, according to FCC map you are well within the coverage area of Fox - KTXL,
If you are responding to the zip code 95618 query, his stations are all not on UHF right now. He has KNTV-DT NBC 11 on VHF 12. There is also KVIE-DT PBS 6 on UHF 53 which is currently slated to switch to VHF 6 in 2009. The CM 4228 is a good choice for the KNTV-DT NBC station, but not if he wants to get KVIE-DT PBS in 2009. coyote1 needs to stick with a full VHF/UHF coverage antenna setup. A Winegard or Channel Master pre-amp is easier than putting up a new antenna, but it may be that the old Radio Shack antenna is not very good for UHF.

coyote1, do you know the model number of the Radio Shack antenna or can you match it approximately to one of the current Radio Shack antennas shown on their website?

coyote1, do you know the model number of the Radio Shack antenna or can you match it approximately to one of the current Radio Shack antennas shown on their website?

There are only three outside antennas on the Radio Shack site; they all are better than what I've got. Basically there are 4 pairs of VHF angled elements, with 6 elements (3 up and 3 down) on the vertical V , plus 6 or so on the front. Total is 18-20 elements or so. The entire antenna is 5-6 feet long (front to back). It is definately a low end unit. It looks similar to the winegard-hd7010 or Channel Master 3016.

the antennas in the class you are using generally are underperformers. their weaknesses stick out when reception conditions are not ideal.

To improve the reception situation

-install a winegard hdp269 preamp to start and see how you make out. the hdp 269 preamp is the suggested amp for the suburbs.

-if the situation is still not to your liking, then replace your current antenna with the winegard hd7082p. The size smaller (hd7080P) is not suggested in your case since it performs poorly on ch6 which you will need moving forward after the transition.

you would use the hdp269 preamp on the antenna replacement (if you decide to do so later) so you should not be concerned. I would not purchase a more powerful amp than the hdp 269 because if you end up replacing the current antenna with one of higher performance the higher gain amp may become an issue.

Thanks for the information and suggestions - I had more or less figured the antenna was an underperformer, but didn't know where to go from here. I've ordered the hdp269 preamp and it sounds like that will do the trick!

Oh man, it's been a while since I read this thread...

But does anyone have any thoughts on a long-range UHF antenna? I'm no rookie -- been chasing this stuff for years now. But those situations were more for a home application with a weak local station. I didn't have much room, so I had to use a bowtie-style antenna.

Now I have more room at a different location and I'd like to try a distant station (for fun, I'm not counting on this to work under all atmospheric conditions). I'd love to hear people's opinions on:

CM 4248/3023 Yagi
Winegard PR-9032
Antennacraft MXU-59

I own the Winegard PR-8800 and CM 4228 already.

On other sites I've read the "long range solution" claiming that the 8-bay bowties are definitely better for long-range reception. But in my experience, comparing the Radio Shack $24.95 UHF yagi and the Antennas Direct 42XG to the bowties, the 8-bays don't seem to work any better. Suffice to say, I don't see the clear superiority of the 4228 that so many claim. (And I think the wind loads of those are too great for my location anyway.)

And some other tests I've seen, like the atechfabrication one, don't seem to support that the 8-bays are superior anyway.

So does anyone have any thoughts on the yagis? Honestly, I'm tempted to try that Antennacraft MXU59 for some reason, but it's claimed gain isn't that great. (Which isn't always a negative -- I find the exaggerated gains from Antennas Direct a real turnoff.)

I don't know why, but my impression of CM isn't the best. Probably for no good reason, but maybe because I am kind of underwhelmed with the CM 4228.

The logical choice might be the Winegard 9032, as they claim high gain for it and I've had good luck with the PR-8800 and a Winegard FM yagi I have. But I thought I'd ask here for opinions.

Thanks, everyone. :)

I prefer the 91xg over all the antennas you have mentioned.

I have screwed around with many of the antennas you mentioned the last 25 years or so and am content with the 91xg.

I tried the cm 4228 recently but was not pleased and it tamed the multipath poorly at my home. if you tried the cm4228 and pr8800 I would not consider the db8.

the yagis you listed are in the second tier performance wise.

I like the 91xg alot...I can honestly say I am rather content and have no need to upgrade again. and that's good.

I prefer the 91xg over all the antennas you have mentioned.

I have screwed around with many of the antennas you mentioned the last 25 years or so and am content with the 91xg.

I tried the cm 4228 recently but was not pleased and it tamed the multipath poorly at my home. if you tried the cm4228 and pr8800 I would not consider the db8.

the yagis you listed are in the second tier performance wise.

I like the 91xg alot...I can honestly say I am rather content and have no need to upgrade again. and that's good.
Thanks for the input, Rick.

I'd almost forgotten about the XG91. I guess I hadn't considered it just because it's so much more expensive than the other ones that are around $50-60 or so shipped. I also was skeptical if it was truly superior to the other yagis like the 4248 or the 9032, or just a more high-tech looking design with a bigger price tag.

But if it's really that much better, it would work well considering I need a lighter antenna with a lower wind load where I live.

Also, I was almost considering ganging two of the cheaper yagis since two of them might cost about what one of the 91s would, but this would certainly be simpler to do. Anyone have any thoughts on if two 9032s would be much better than one 91XG?

Man, 200 pages and I'm not wanting to look for what I need and I suspect it has been covered many times.... so can anyone point me to or answer this question?

I need to use two directional antennas to pickup all my local OTA channels one or two are not in line with the others. So, I want to use a two antenna setup and that's where I'm concerned.

I know of the problems with ghosting and such when dealing with analog broadcasts, but not sure how this applies with digital. I know there are rules (but I'll need to find those again) on placement, cable length to joiner, etc. but this is all new to me.

I'll be using a CM 8 bow tie (can't remember the model) and a CM stealth, CM 7777 (may be 7775) preamp. I know there's filters and blocks that I can get if I've got problems with that setup. But, I'm holding off on getting those until I know what's needed.

Anyone got advice on pulling this off?

I need to use two directional antennas to pickup all my local OTA channels one or two are not in line with the others. So, I want to use a two antenna setup and that's where I'm concerned.

Anyone got advice on pulling this off?
It depends on the channel number and directions. A list of the channels that you want to receive or your zip code for antennaweb would be a start.

It depends on the channel number and directions. A list of the channels that you want to receive or your zip code for antennaweb would be a start.


Ok, that's odd. Since moving here I haven't looked at antennaweb and your prompting got me to check it out.

Strange thing is that everything I wasn (excpet for PBS) appears it should be in the same direction, one channel is 1° off, but that shouldn't make a huge difference...


* red - uhf WRAL-DT 5.1 CBS RALEIGH NC 162° 21 53
* red - uhf WRAZ-DT 50.1 FOX RALEIGH NC 162° 21 49
* red - uhf WRDC-DT 28.1 MNT DURHAM NC 162° 21 27
* red - uhf WTVD-DT 11.1 ABC DURHAM NC 163° 21 52
* red - uhf WLFL-DT 22.1 CW RALEIGH NC 162° 21 57
* red - uhf WNCN-DT 17.1 NBC GOLDSBORO NC 162° 21 55
* violet - uhf WUVC-DT 40.1 UNI FAYETTEVI NC 216° 34 38
* violet - uhf WRPX-DT 47.1 ION ROCKY MNT NC 78° 30 15
* violet - uhf WUNC-DT 4.1 PBS CHAPEL HI NC 266° 26 59


I guess the more interesting thing may be my signal strengths...

94% 50.1 FOX RALEIGH NC 162° 21 49
93% 28.1 MNT DURHAM NC 162° 21 27
54% 11.1 ABC DURHAM NC 163° 21 52
<20% 22.1 CW RALEIGH NC 162° 21 57
<10% 17.1 NBC GOLDSBORO NC 162° 21 55
--- 40.1 UNI FAYETTEVI NC 216° 34 38
--- 47.1 ION ROCKY MNT NC 78° 30 15
--- 4.1 PBS CHAPEL HI NC 266° 26 59


I believe my antenna is aimed for 162°, 20 miles away and the broacasting power must be way off between 5.1, 50.1, 28.1, 11.8, 22.1 and 17.1.

What I'm really missing is 17.1 (NBC) on the 162° path, but not coming in at all.
The PBS feed at 4.1 would be nice to have. That's what I'm looking at the second antenna for.

Hey Jeff D... Where exactly are you? I'm between Raleigh and Wilmington... I just ordered a bunch o' crap to install a 91xg. I really wanted a Blake JBX 21WB but couldn't find one in the states and Blake wanted 150% of purchase price to ship it!

Ok, that's odd. Since moving here I haven't looked at antennaweb and your prompting got me to check it out.

Strange thing is that everything I wasn (excpet for PBS) appears it should be in the same direction, one channel is 1° off, but that shouldn't make a huge difference...


* red - uhf WRAL-DT 5.1 CBS RALEIGH NC 162° 21 53
* red - uhf WRAZ-DT 50.1 FOX RALEIGH NC 162° 21 49
* red - uhf WRDC-DT 28.1 MNT DURHAM NC 162° 21 27
* red - uhf WTVD-DT 11.1 ABC DURHAM NC 163° 21 52
* red - uhf WLFL-DT 22.1 CW RALEIGH NC 162° 21 57
* red - uhf WNCN-DT 17.1 NBC GOLDSBORO NC 162° 21 55
* violet - uhf WUVC-DT 40.1 UNI FAYETTEVI NC 216° 34 38
* violet - uhf WRPX-DT 47.1 ION ROCKY MNT NC 78° 30 15
* violet - uhf WUNC-DT 4.1 PBS CHAPEL HI NC 266° 26 59


I guess the more interesting thing may be my signal strengths...

94% 50.1 FOX RALEIGH NC 162° 21 49
93% 28.1 MNT DURHAM NC 162° 21 27
54% 11.1 ABC DURHAM NC 163° 21 52
<20% 22.1 CW RALEIGH NC 162° 21 57
<10% 17.1 NBC GOLDSBORO NC 162° 21 55
--- 40.1 UNI FAYETTEVI NC 216° 34 38
--- 47.1 ION ROCKY MNT NC 78° 30 15
--- 4.1 PBS CHAPEL HI NC 266° 26 59


I believe my antenna is aimed for 162°, 20 miles away and the broacasting power must be way off between 5.1, 50.1, 28.1, 11.8, 22.1 and 17.1.

What I'm really missing is 17.1 (NBC) on the 162° path, but not coming in at all.
The PBS feed at 4.1 would be nice to have. That's what I'm looking at the second antenna for.

Remember also that several of your stations will be moving their transmission frequencies in 2009 when analog goes away. Most of them are just moving from one UHF channel to another but WTVD is moving back to channel 11 in VHF-hi. Since it sounds like you have a CM4228, this is just about the only UHF antenna with any sort of VHF-hi performance and so you may be lucky and receive WTVD OK when it moves channels. Otherwise you will need to add a VHF-hi antenna, and couple it to the output of the CM4228 via the CM7777.

[QUOTE=ChocoLab]Oh man, it's been a while since I read this thread...

But does anyone have any thoughts on a long-range UHF antenna?

So does anyone have any thoughts on the yagis?



I use the cm 4248 with the cm 7777 amp. The stations I watch are between 56 and 72 miles away in the Carolinas, and with 180 degree rotation I can get two Atlanta stations on a daily basis, 80 miles away. All of the Carolina station transmitters are on mountain tops, and I also have good elevation, with line of site to all but one. The Atlanta reception is just being in the right spot. I keep having ideas of a BIG antenna to receive all of the Atlanta stations. Of course weather and time of year are always a player. I am also open to suggestions. Happy viewing.

Anyone have any thoughts on if two 9032s would be much better than one 91XG?

Better, yes, assuming it's set up correctly. Stacking is a fair amount of fiddling and takes some time to get the best out of the setup though.

If you're going to the trouble, I'd say stack two XG91's.

I am also open to suggestions. Happy viewing.

Here you go:

Or, if you're really feeling crazy.:)

Or, if you're really feeling crazy.:)
WOW! :eek: Ground control to Major Tom! ;)

Or, if you're really feeling crazy.:)

I can't imagine the headache and hassle that getting that kind of setup exactly tuned must have caused. I've had enough trouble just getting my single antenna placed exactly right so all my channels come in without losing one or two due to small variations in placement.

Or,if you need high gain and extreme directivity,try this....

http://community-2.webtv.net/GregBarker/NewTowerAntennas/

Here you go:


Thanks for the idea, but those were really ugly sites, and sights too. I may gang another 4248 someday, but nothing more, maybe. I hope to wait until Feb. 09 to see what comes out of the wash before deciding what to use. I may need a high vhf or a low vhf, or both.
If those sites were yours, they really didn't look that bad. I'll bet the wife was out of town when those things went up.

OOPS, I took a look at your stuff, sorry about the ugly comment. I live pretty much in the sticks myself, but how far away are the stations you are trying to pull in?

It's a two-input combiner with a band pass filter on one input and a band stop filter on the other.

The typical use for it is that if you have two antennas, one pointed at several TV transmitters, and the other pointed in another direction at a lone transmitter, you can combine the two antenna signals without the two antennas' signals interferring with each other. (It's rare that you can successfully take two antennas and connect their signals with a simple combiner.)

You order the Jointenna tuned for a specific channel number, the channel of the lone transmitter. You then hook that lone antenna's signal into the bandpass filter input, and ONLY that one channel's signal is passed on to the internal combiner. You hook the other antenna's signal into the band stop filter, and every signal from that antenna EXCEPT the specified channel is passed on to the internal combiner.

If the Jointenna is working properly, the signals that are intentionally passed through from either input are not attenuated very much. In my case, a non-specified channel's signal coming into the band stop input dropped from a reading of 70 on my TV's meter to 67....a nominal amount. The specified channel's signal coming into the band pass filter dropped from a reading of 73 to a value in the low 40s, making it useless on its own. I scrounged up an amp to give a preliminary boost to the specified channel's antenna, and that got the signal to come through at about a value of 57 on my TV, but that's a kludge that shouldn't be needed. I have two other Jointennas, and their specified channels tend to pass signal through with only a drop of about 3, like I'd expect.

So the unit in question is either outright faulty, or (I'm guessing more likely) not tuned properly. And that's what p@@@@@ me off , er, uh, bothers me. When you order a Jointenna, you have to wait several weeks for it to be custom tuned. If they're not going to tune it any better than this, I'd rather do it myself.

Open question to all: Have any of you tuned a Jointenna yourself? Is it worth trying on my own, or are the adjustments too quirky to try?

If you are using a Jointenna with a Pre-amp, where do you put in the amplifier, before the Jointenna, or after?

don

the 91xg is a better performer than the cm4248 by a few db across most of the uhf band.

you may be better off replacing the cm4248 now. it is only about $90 delivered from solid signal.

once it is installed you may not need to stack two.

Thanks Rick. The 91xg has been a temptation, it shows almost 7 db more gain than the 4248, that's a lot. I would like to hear from someone who uses ONE (1). I am assuming by your location, you would not need that much gain.

Thanks Rick. The 91xg has been a temptation, it shows almost 7 db more gain than the 4248, that's a lot. I would like to hear from someone who uses ONE (1). I am assuming by your location, you would not need that much gain.
I installed a 91XG about 8-10 mos ago and couldn't be happier with it. I'm about 65-75 miles from Sutro Tower in SF, with lots of hills in between and no line of sight. The 91XG brings in more channels and is stabler than anything else I've tried which included the CM 4228 and CM4248.

To qualify the above I should say I'm also using a Research Communications pre-amp, the combination of the 2 have given me stable reception on some channels where I would struggle with constant dropouts previously.

http://www.researchcomms.com/hdtv.html
HDTV Low Noise Amplifiers and Preamplifiers, Preamps, NF 0.4 dB - Research Communications Ltd UK

Thanks for the idea, but those were really ugly sites, and sights too.
OOPS, I took a look at your stuff, sorry about the ugly comment. I live pretty much in the sticks myself, but how far away are the stations you are trying to pull in?

Greg's setup is alot prettier.:)

I'm between 60-140 miles away. My primary stations are in Knoxville about 65 miles to the south.

Remember also that several of your stations will be moving their transmission frequencies in 2009 when analog goes away. Most of them are just moving from one UHF channel to another but WTVD is moving back to channel 11 in VHF-hi. Since it sounds like you have a CM4228, this is just about the only UHF antenna with any sort of VHF-hi performance and so you may be lucky and receive WTVD OK when it moves channels. Otherwise you will need to add a VHF-hi antenna, and couple it to the output of the CM4228 via the CM7777.

I live 45 miles from WNCT channel 10/ 9.1-9.2 and use a UHF 4221 with VHF/UHF amp and have no problems picking up the VHF with it pointed in just about any direction. With the UHF frequencies however, I find I have to be just about right on with the aim.

If you are using a Jointenna with a Pre-amp, where do you put in the amplifier, before the Jointenna, or after?

I put a preamp at every antenna, so they're upstream of the jointennas. Yes, it's more expensive than a single amp after all the combiners, but I wanna amplify the signals before line loss and devices attenuate them into the noise floor (never to be heard from again).

You might get away a single amp in many situations, but this is becoming more of a hobby than a necessity for me, so the more toys, the better !

I just have a quick question. I have a 91xg and a VHF/UHF combo antenna tied together with a CM 7777 pre-amp. I know that if you are combining identical antennas you are supposed to use identical cable lengths from the antennas to the joiner, but am I supposed to do the same for my situation? Currently, the cable from my 91xg to the pre-amp is about twice the length of the one from the combo antenna to the 7777. Can this cause reception problems? I am currently having issues with one channel and I am trying to determine if it is being caused by multipath or some other problem.

Are you using the 91xg for VHF and the combo for VHF? If so, make sure the 7777's switch is set for VHF on one input and UHF on the other as marked. If you are using the two antennas for UHF channels from different directions, that causes multipath issues that may be addressed by connecting them with a jointenna tuned for one station on the secondary antenna. If you are trying to make a stacked antenna system which is the only scenario requiring equal length leads, identical antennas are required.

Also, if any station is closer than 20-30 miles away depending on strength, you could be getting preamp overload.

[CODE]QUOTE=Rick0725] I also use the 91xg at my home and am pleased with the performance.

Keenan

I placed an order today for the 91XG, and the Winegard YA 1713. The combo will be aimed toward Atlanta, with a cm 7777 in line.
Thanks for the info on the XG, I should know the results within a couple weeks.

If I were to tie together 2 CM 4221 antennas with a splitter (understading the need for indentical cable) would that antenna function similarly to the 4228? Will there be a gain over the 4221?

Not really...the CM-4228 uses a low-loss quarter-wave feed structure vice lossy combiner.

Are you using the 91xg for VHF and the combo for VHF? If so, make sure the 7777's switch is set for VHF on one input and UHF on the other as marked. If you are using the two antennas for UHF channels from different directions, that causes multipath issues that may be addressed by connecting them with a jointenna tuned for one station on the secondary antenna. If you are trying to make a stacked antenna system which is the only scenario requiring equal length leads, identical antennas are required.

Also, if any station is closer than 20-30 miles away depending on strength, you could be getting preamp overload.

Yes, I am using the combo for VHF only. I am about 36 miles from the transmitters. Thank you for eliminating the cable length as one cause of my problems with the one channel I am having trouble with.

Not really...the CM-4228 uses a low-loss quarter-wave feed structure vice lossy combiner.

I should clarify.

I bought a 4221, but I don't think it's enough antenna for me. I am just short of pulling in what I need. I was thinking of purchasing another to combine, to get close to the effect of the 4228, without spending another $80. Plus, I'm using the 4221 in my attic, and I'm not sure I could fit the 4228 through the door.

Is this nuts?

I bought a 4221, but I don't think it's enough antenna for me. I am just short of pulling in what I need. I was thinking of purchasing another to combine, to get close to the effect of the 4228, without spending another $80. Plus, I'm using the 4221 in my attic, and I'm not sure I could fit the 4228 through the door.

Is this nuts?

If your antenna is on the threshold of working/not working, you might consider its location. It's not always enough for your antenna to be pointed in the right direction. It's also a matter of where it is located. Something simple as moving it a few feet (or even inches) can make a difference. In my case, an antenna located in my garage's attic pointed through the house works better than the same antenna located in the house's attic. It's not magic, but it is a science of subtleties.

Connecting two 4221s together as you describe should work. You won't get the additional VHF-hi gain of the real 4228, but in general you should get additional gain.

Note the Antennas Direct DB8 works exactly like this; it's two DB4s with a combiner.

If you've got a long coax run out of your attic you might want to consider a preamp instead of or in addition to the antenna.

Connecting two 4221s together as you describe should work. You won't get the additional VHF-hi gain of the real 4228, but in general you should get additional gain.

Note the Antennas Direct DB8 works exactly like this; it's two DB4s with a combiner.

If you've got a long coax run out of your attic you might want to consider a preamp instead of or in addition to the antenna.
I have a preamp installed already. It helps tremendously, but I'm on the fringe of the signal. I pull in the analog, clearly, but the digital is not there.

thanks,

paul

I should clarify.

I bought a 4221, but I don't think it's enough antenna for me. I am just short of pulling in what I need. I was thinking of purchasing another to combine, to get close to the effect of the 4228, without spending another $80. Plus, I'm using the 4221 in my attic, and I'm not sure I could fit the 4228 through the door.

Is this nuts?
Here is how to fit CM-4228 through a small attic access hatch:
http://www.avsforum.com/avs-vb/showthread.php?p=10612061&highlight=cm4228+tabs#post10612061
And is only known UHF-only antenna with significant hi-VHF band gain.

Sure, you could combine two CM-4221's with a simple splitter/combiner...
just won't be as good as CM-4228....and very poor for VHF.
Combining gain depends on careful matching of gain and phase,
so make sure antennas are securely aligned in the same plane.

Which Preamp? And can you provide location, say to nearest cross streets?

Here is how to fit CM-4228 through a small attic access hatch:
http://www.avsforum.com/avs-vb/showthread.php?p=10612061&highlight=cm4228+tabs#post10612061
And is only known UHF-only antenna with significant hi-VHF band gain.

Sure, you could combine two CM-4221's with a simple splitter/combiner...
just won't be as good as CM-4228....and very poor for VHF.
Combining gain depends on careful matching of gain and phase,
so make sure antennas are securely aligned in the same plane.

Which Preamp? And can you provide location, say to nearest cross streets?
I'm at 21093. Nearest cross St. is Seminary Ave and Joppa Road

I'm using the Winegard HDP-269 pre-amp

GoogleEarth and Yahoo Maps don't show those streets crossing anywhere....

I see where W. Joppa Rd crosses I83/I695 and runs into Falls Road,
which then goes 1/2-mile further North to W. Seminary Ave.

Am I close??? Can you get me a little closer???
Distance from the 200-ft high hill towards the North makes a difference...

LAT/LONG (rounded to three decimals) is also good....

Anyone else have problems with CM Jointennas being bad out of the box? I bought three, two work fine, one doesn't pass it's tuned channel through its bandpass filter without knocking its level down a lot. Are there any alternatives to these devices? If they're going to be faulty or mistuned (after waiting a month to arrive), I'd like to consider other options... preferably something I can tune myself.

I've never known of a Jointenna being mistuned or bad out of the box, and I've bought a lot of them.

It's been several years since I bench tested a bunch of them using a white noise generator and a spectrum analyzer, but as I recall, the insertion loss on the single channel input was typically a dB or two, whereas the full, out of band rejection on that port was around 20 dB in the UHF band. Incredibly, the rejection was only about 5 dB on the two, non-tunable VHF lowband Jointennas I tested.

Losses incurred through any passive device cannot be measured by the signal quality percentage meters that are incorporated into receivers. These numbers are derived through the application of mystery algorithms that rely heavily on the amount of forward bit error correction taking place. If you use a Jointenna as a bandpass filter on a weak signal in a market that also has some very strong signals, often the displayed signal strength percentage will actually go up, especially on receivers with early generation tuners, because it will reduce the overload that beats up the weaker signal in the tuner. I recently was able to increase the displayed signal strength of some weak signals that I was feeding into a Radio Shack Accurian receiver by 15% to 20% by individually bandpass filtering them.

If you post your map co-ordinates and tell us what you are using for antennas, maybe we can figure out why certain channel couplings may be difficult in your situation.

I put a preamp at every antenna, so they're upstream of the jointennas. Yes, it's more expensive than a single amp after all the combiners, but I wanna amplify the signals before line loss and devices attenuate them into the noise floor (never to be heard from again).

Generally, a very bad idea, and believe me, I've experimented at more of this than any of you ever will. You will invariably degrade the weak signal more by the intermodulation distortion developed in the preamp than you could ever degrade it by moving it a dB or so closer to the thermal noise floor by preamplifying it.

Those published "maximum input level" figures that preamp manufacturers furnish, even when accurate for their application, are the maximum level of equal strength inputs, such that they will not excessively degrade any other equal strength channels. But a preamp receiving a few relatively strong signals that might be 10 dB or more below that maximum inpout level will still wreak havoc on desired signals that commonly 30 or more dB weaker than the stronger ones.

...I work for a residential developer and we have a few new building coming up in the Chicago downtown area (South Loop, specifically Roosevelt & S. Michigan.). One 20 story and one 10 story building. I've been approached by numerous local cable providers trying to get us to subscribe. Would deploying an hd antenna on the roof be a viable alternative to offering free high quality channels to the buildings residents?
I am willing to spend more time studying the art and science behind it, would I be able to follow through the deployment of the cabling and antennas myself or is it in my best interest to get a pro to do it? Any idea what the cost might be associated with this?.

I just stumbled across this post while looking up something else.

1. No developer will ever have the expertise to develop an MATV headend (antenna array and procesing) in house. If you want to include this amenity in your buildings, you need someone local to become your "antenna guy" and to develop something affordable that can be adapted to each situation.

2. As far as wiring is concerned, you should always pay for your own "home run" wiring from the cable closets to each unit. If you take free wiring from a cable company, it becomes cost prohibitive for any units to ever obtain TV signal any other way.

3. You should run two home run lines to each unit. Coax costs less than ten cents per foot. By having two home runs to each unit, any resident will be able to also receive signal from a second source, be it your master antenna system, DBS satellite (DirecTV or DISH, for example) or even a second cable company.

I've only done one Chicago satellite headend installation (N Michigan Ave., ~30 story building) and while I didn't install any off-air antennas there, I did eyeball the off-air reception situation, and while their roof had line-of-sight to both towers, there would still have been the likelihood of strong multipath reflections bounding off taller buildings that would have to be ameliorated by a headend designer/installer who knew how to deal with them.

The future has arrived.


http://www.starkelectronic.com/achub22.jpg
http://www.starkelectronic.com/allant.htm

Antennacraft channel 7-69 antenna for $29.95.

Based on its physical appearance, it probably develops around 9dB of gain at most UHF frequencies, and maybe 4-5dB of VHF highband gain, but perhaps more importantly, gain across the VHF channel will be much flatter than it is with a Channel Master 4228.

And it is always considered to be better to have the mast behind the UHF dipole, as this antenna does, rather than in front of it, but I don't know how much difference that actually makes.

Nice to see a high band vhf/uhf combo on this side of the pond.

I guess we'll have to wait a little longer for the 7-51 tuned models. :)

The future has arrived.


http://www.starkelectronic.com/achub22.jpg
http://www.starkelectronic.com/allant.htm

Antennacraft channel 7-69 antenna for $29.95.

Based on its physical appearance, it probably develops around 9dB of gain at most UHF frequencies, and maybe 4-5dB of VHF highband gain, but perhaps more importantly, gain across the VHF channel will be much flatter than it is with a Channel Master 4228.

And it is always considered to be better to have the mast behind the UHF dipole, as this antenna does, rather than in front of it, but I don't know how much difference that actually makes.

I wondered if/when we would see antennas like this. For everyone except those with UHF only, and the unfortunate few who will still have to put up with vhf-lo after the digital transition in 2009, this is a great idea.

GoogleEarth and Yahoo Maps don't show those streets crossing anywhere....

I see where W. Joppa Rd crosses I83/I695 and runs into Falls Road,
which then goes 1/2-mile further North to W. Seminary Ave.

Am I close??? Can you get me a little closer???
Distance from the 200-ft high hill towards the North makes a difference...

LAT/LONG (rounded to three decimals) is also good....

I'm right at the spot where 695 and I-83 intersect. In fact, the road is in my backyard.

No Gain & Beamwidth specs (only "range") on antennacraft website:
http://www.antennacraft.net/HBU22.htm

It's hard to tell from tiny photo, but UHF section seems "similar" to W-G PR-9018:
http://www.winegard.com/offair/pdf/Pr-9018.pdf
which claims 13-14 dBd gain at low and mid-band UHF.

Since the Hi-VHF section is probably a 3 (or 4?) element "LPDA",
above gain seems optimistic.
PS: In most combo antennas, the folded dipole is the active element
for the forward UHF section and a feed structure continues to the rear
for the VHF LPDA section.

Fracarro (Italy) 4E512F is 4-element, Band 3 (Hi-VHF, 174-230 MHz) YAGI
with 2-3 dBd (4-5 dBi) gain.
You can download Fracarro and Lacey's Catalog from www.laceys.tv (Aussie) website....
PS: Check gain for 4-Bay & 2-element Yagis to verify whether they use dBd or dBi (usually).

Funke (Netherlands) 4-element, Hi-VHF YAGI claims 3-4 dBd (5-6 dBi) gain:
http://www.funke.nl/library/120_042002_s1304_051203_790500471.pdf

An LPDA is usually less efficient than a YAGI....
Hence HBU-22 gain is probably closer to 3 dBd for VHF....esp. with UHF section perturbation.

I look forward to seeing some meaningful on-air comparisons to CM-4228.
I think CM-4228 will equal if not outperform HBU-22 in Hi-VHF and for sure in UHF.

================================
Here is the A2610 combo from Dipol (Poland), which uses a corner reflector YAGI
to improve the gain of the rear VHF section, resulting in 4-5 dBd Hi-VHF gain:
http://www.dipol.com.pl/sx/en/catalog/TV_Antenna_Set_DIPOL_26-6-12-21-69_26-element_Digital_A2610.htm
Surely Hi-VHF gain for (LPDA) HBU-22 is somewhat less....

===============================
FYI: Fracarro also makes several LPDA that cover both Hi-VHF Band 3 and UHF,
using a long COMMON dual-boom feed structure with small UHF elements
at the front and longer Hi-VHF elements towards the back....
Fracarro LP345F gain specs claim 7 dBd (9 dBi) for both Hi-VHF and UHF bands.

Ditto specs for LPDA from Funke (Netherlands):
http://www.funke.nl/library/235_156602_lp1716f_260504_geen%20instr.pdf

Dipol (Poland) makes a similar LPDA, claiming 6 dBd for Hi-VHF and
12 dBd for UHF (dBd = dBi - 2.15 dB):
http://www.dipol.com.pl/sx/en/catalog/Broadband_TV_Antenna_logarithmic-periodic_dipolar_-_LOG_2-65_A4015.htm
PS: Frequencies help to identify "Band 3"...but in this case, ya gotta check
the country's channel conversion chart....in Poland Hi-VHF is CH6-12.
It's 8.52 Euros (before VAT)....plus (mostly) shipping....

=============================
Televes (Spain) added some extended elements to the UHF DAT-45,
claiming 6.3 dBd (8.5 dBi) Hi-VHF Gain:
http://www.televes.com/ingles/producto/ficha.asp?COD=229
http://www.televes.com/ingles/producto/caracteristicas.asp?COD=229
This is probably MAX gain, esp. given Televes overly optimistic spec practice....

Wouldn't want to leave out the funky Hi-VHF/UHF Combos from Funke (Netherlands):
http://www.funke.nl/library/285_039002_fpa3542_070604_790500004.pdf
http://www.funke.nl/library/270_175702_dcs1735_210604_790501757.pdf
http://www.funke.nl/library/280_178502_dcrs1753_210604_790501785.pdf
http://www.funke.nl/library/280_178502_dcrs1753_210604_790501785.pdf

Be sure to at least look at this one:
http://www.funke.nl/library/280_178702_dcrs1760_210604_790501787.pdf
Look....up in the sky.....it's a bird....it's a plane....no, it's a Funke.....

Maybe we'll see more Hi-VHF/UHF combo antennas in U.S. as we approach Feb2009....
PS: Funke (like most of the world) uses dBi, so subtract 2.15 dB to convert to dBd.

I'm right at the spot where 695 and I-83 intersect. In fact, the road is in my backyard.

Here's my situation, maybe you can help. For the folks from the Washinton/Balitmore thread, sorry for the repeat.

Anyway, from my location, I'm trying to pick up WPMT, a FOX station in York, PA. I moved my 4221 to a pole over my roof, following the "Higher is always better" advice. It's now about 40 feet in the air.

I still can't get the digital signal on 47. I can get analog on 43, really well, but I think there is interference. Can somebody confirm what I am seeing?

On analog 43, I get a VERY clear signal, no jumping or skipping, but there is a fuzzy grain to the picture. If I get close, or put it on my 42 inch plasma, it looks like an Impressionist painting you're too close to. Is this interference? I have a Jointenna on the way, because at 4 miles from the Baltimore Towers, with WBFF broadcasting at 46, I think that may be an issue.

Also, I can pull in channel 49, WGCB, which is at 6.4 degrees according to tvfool.com. WPMT (my target) is at 3.9 degrees. WGCB is 33 miles away, as opposed to 42 miles from WPMT. This makes me think I may need more gain. With that little difference in the azimuth, I should have a good shot with a higher gain antenna, no?

thanks,

paul

Anyway, from my location, I'm trying to pick up WPMT, a FOX station in York, PA. I moved my 4221 to a pole over my roof, following the "Higher is always better" advice. It's now about 40 feet in the air.

I still can't get the digital signal on 47. I can get analog on 43, really well, but I think there is interference. Can somebody confirm what I am seeing?

On analog 43, I get a VERY clear signal, no jumping or skipping, but there is a fuzzy grain to the picture.
I have been trying to help Paul on the Washington-Baltimore thread and via private messages. Paul, if I may, here are the analog and digital stations in the region to help the experts get a better understanding of your possible interference issues with getting WPMT-DT 43 (DT=47) at some 40 miles to his north.

DT 42 - WMPT-DT MPT 22 in Annapolis
DT 43 - WPXW-DT Ion/Pax 66 in Manassas, VA (90 kW and well south of him)
TV 43 - WPMT Fox in in York/Harrisburg, PA
DT 44 - WWPB-DT MPT 31 in Hagerstown, MD (long ways off)
TV 45 - WBFF Fox 45 in Baltimore (~ 4 miles away)
DT 46 - WBFF-DT Fox 45 in Baltimore (~ 4 miles away at 550 kW)
DT 47 - WPMT-DT Fox 43 in York/Harrisburg, PA (40 miles to the north)
DT 48 - WRC-DT NBC 4 in DC (~ 42 miles to the south)

The issue with WPMT-DT on UHF 47 is possibly adjacent channel interference due to the close distance to WBFF-DT on UHF 46. I have suggested to Paul that he put up a metal mesh screen behind the antenna as an experiment just to see if that helps him get a temporary lock on WPMT-DT. Paul, what do you get on the signal meter when you tune to digital channel 47 - if your ATSC tuner allows it? Perhaps you should borrow a 5th gen Samsung DTB-H260F which is ATSC only so you can manually tune to UHF 47 and see whether you get anything on the signal meter. I have also strongly suggested you take out the pre-amp entirely and see what you can get without it. Have you tried that?

It's hard to tell from tiny photo, but UHF section seems "similar" to W-G PR-9018:...

The PR-9018 has two more reflector and two more director elements. I derived my 9dB estimate from the specs for the UHF section of the Winegard PR-5456. (http://www.winegard.com/offair/antennas/pr5646.htm)

I was guessing that the middle VHF element was a dipole, with a reflector behind it and a director ahead, but again, the picture is just too small to see for sure.

I have been trying to help Paul on the Washington-Baltimore thread and via private messages. Paul, if I may, here are the analog and digital stations in the region to help the experts get a better understanding of your possible interference issues with getting WPMT-DT 43 (DT=47) at some 40 miles to his north.

DT 42 - WMPT-DT MPT 22 in Annapolis
DT 43 - WPXW-DT Ion/Pax 66 in Manassas, VA (90 kW and well south of him)
TV 43 - WPMT Fox in in York/Harrisburg, PA
DT 44 - WWPB-DT MPT 31 in Hagerstown, MD (long ways off)
TV 45 - WBFF Fox 45 in Baltimore (~ 4 miles away)
DT 46 - WBFF-DT Fox 45 in Baltimore (~ 4 miles away at 550 kW)
DT 47 - WPMT-DT Fox 43 in York/Harrisburg, PA (40 miles to the north)
DT 48 - WRC-DT NBC 4 in DC (~ 42 miles to the south)

The issue with WPMT-DT on UHF 47 is possibly adjacent channel interference due to the close distance to WBFF-DT on UHF 46. I have suggested to Paul that he put up a metal mesh screen behind the antenna as an experiment just to see if that helps him get a temporary lock on WPMT-DT. Paul, what do you get on the signal meter when you tune to digital channel 47 - if your ATSC tuner allows it? Perhaps you should borrow a 5th gen Samsung DTB-H260F which is ATSC only so you can manually tune to UHF 47 and see whether you get anything on the signal meter. I have also strongly suggested you take out the pre-amp entirely and see what you can get without it. Have you tried that?

On my Directv box (HR20), I get nothing most of the time on 47, but an occasional blip at 25 percent. So, I must be aiming right, correct?

As for the Amp. I have not pulled it out. Let me ask a question, as I am still a bit of a newbie. The amp has 2 pieces. One I put on the mast, the other (the power injector) I have near the receiver connected to the downlead. If I wanted to take the amp out of the circuit, do I need to remove the Mast mounted piece as well as the power injector?

When I took just the power injector out of the circuit, I got no difference in my digital reception, but a complete loss of analog 43.

Here's my situation, maybe you can help.

Anyway, from my location, I'm trying to pick up WPMT, a FOX station in York, PA. I moved my 4221 to a pole over my roof, following the "Higher is always better" advice. It's now about 40 feet in the air.

paul

You have about 4 factors preventing reception of York, PA.

1. Weak signal
2. Strong and close locals
3. Inability for any multiple channel preamp to work with close locals
4. The possible need for a larger antenna

The first thing that I'd try is a single channel 47 filter between the 4221 and the HDP-269 preamp. Of course, once you do that, you'll need a second antenna for everything else. Ideally, you need an adjacent channel filter, but they are expensive. You can try a cheaper filter if you like, but it may not work. Even a pricey adjacent channel filter might not be enough without more antenna gain.

http://www.tinlee.com/BandPass_Matv_Catv.htm#CF7:%20Semi-Adjacent%20Bandpass%20(any%20channel%205-800%20MHz)
http://www.solidsignal.com/prod_display.asp?PROD=SS4805
http://www.cefilter.com/products/display_product.asp?ProdID=57&CatID=3
http://www.microwavefilter.com/bandpass.htm

I looked at 39.4226 and -76.6706 on tvfool. If those numbers are exact, I would not try too much more or spend much money. If not, please put an X on your house and repost it.
http://www.topozone.com/map.asp?lat=39.42249&lon=-76.67093&s=24&size=l&u=4&datum=nad27&layer=DRG

You have about 4 factors preventing reception of York, PA.

1. Weak signal
2. Strong and close locals
3. Inability for any multiple channel preamp to work with close locals
4. The possible need for a larger antenna

The first thing that I'd try is a single channel 47 filter between the 4221 and the HDP-269 preamp. Of course, once you do that, you'll need a second antenna for everything else. Ideally, you need an adjacent channel filter, but they are expensive. You can try a cheaper filter if you like, but it may not work. Even a pricey adjacent channel filter might not be enough without more antenna gain.

http://www.tinlee.com/BandPass_Matv_Catv.htm#CF7:%20Semi-Adjacent%20Bandpass%20(any%20channel%205-800%20MHz)
http://www.solidsignal.com/prod_display.asp?PROD=SS4805
http://www.cefilter.com/products/display_product.asp?ProdID=57&CatID=3
http://www.microwavefilter.com/bandpass.htm

I looked at 39.4226 and -76.6706 on tvfool. If those numbers are exact, I would not try too much more or spend much money. If not, please put an X on your house and repost it.
http://www.topozone.com/map.asp?lat=39.42249&lon=-76.67093&s=24&size=l&u=4&datum=nad27&layer=DRG

I'm a little east of there. I looked at TV Fool, and they show WPMT as Grey with an antenna height of 39 Ft or less. Red with 40 Ft. or more. I am at 40 feet now.

As for the filter, I have a CM Jointenna ordered for channel 47. I only care about that one channel, as I have locals on Directv in HD.

When I get the Jointenna, should I put it before the amp? Does that mean before the Mast mounted part too?

Also, is it worth upgrading to a CM 4228 before the jointenna comes, or is there a shot my 4221 will pull in the channel with the Jointenna?

I wouldn't spend any money for the 4228 before the filter arrives. You may get this whole thing working on-the-cheap with what you have already bought.

What does TV fool say the relative signal strengths are? The CM will have a front to back ratio of over 20dB, and weaker DTV signal can typically be processed alongside an adjacent DTV signal that is about 26 to 28 dB stronger. I'm pretty sure that the 26 to 28 dB differential is measured in dBmV of signal power. If TV fool furnishes signal strengths in volts rather than in watts, you'll have to do some thinking to figure out if that ratio is plausible.

Should this antenna be able to develop that signal level differential with that antenna at this location? If so, then the next step will be to avoid preamplifier intermodulation with the bandpass filter.

If you can't get your channel 47 signal up to within 26 to 28dB of your channel 46 hitting the back of the antenna, but if you have access to a signal meter, you might point another antenna at the channel 46 transmitter, pad its output down so that it is exactly the same coming from both antennas, and then couple them through a hybrid splitter/combiner and move the antenna targeted at the channel 46 transmitter towards that trnasmitter until the measured, combined channel 46 signal strength reaches its minimum because the two signal sources are 180 degrees out of phase.

Unfortunately, the point at which the channel 46 boxcar is weakest might vary across its band. If I were going to try to phase cancel or phase mitigate a strong UHF signal, I would probably use Winegard PR-9032s, because it might be impossible to get all of the dipole elements of a 4-bay or 8-bay antenna to be in perfect sync with each other.

I wouldn't spend any money for the 4228 before the filter arrives. You may get this whole thing working on-the-cheap with what you have already bought.

What does TV fool say the relative signal strengths are? The CM will have a front to back ratio of over 20dB, and weaker DTV signal can typically be processed alongside an adjacent DTV signal that is about 26 to 28 dB stronger. I'm pretty sure that the 26 to 28 dB differential is measured in dBmV of signal power. If TV fool furnishes signal strengths in volts rather than in watts, you'll have to do some thinking to figure out if that ratio is plausible.

Should this antenna be able to develop that signal level differential with that antenna at this location? If so, then the next step will be to avoid preamplifier intermodulation with the bandpass filter.

If you can't get your channel 47 signal up to within 26 to 28dB of your channel 46 hitting the back of the antenna, but if you have access to a signal meter, you might point another antenna at the channel 46 transmitter, pad its output down so that it is exactly the same coming from both antennas, and then couple them through a hybrid splitter/combiner and move the antenna targeted at the channel 46 transmitter towards that trnasmitter until the measured, combined channel 46 signal strength reaches its minimum because the two signal sources are 180 degrees out of phase.

Unfortunately, the point at which the channel 46 boxcar is weakest might vary across its band. If I were going to try to phase cancel or phase mitigate a strong UHF signal, I would probably use Winegard PR-9032s, because it might be impossible to get all of the dipole elements of a 4-bay or 8-bay antenna to be in perfect sync with each other.

Mike, you lost me on almost all of that. I will probably wait until I get the Jointenna to see of that works. After that, I don't know.

Can you answer something for me? Where do I put the Jointenna? Does it have to be inline before the pre-amp with just 1 antenna? If so, what's the best way to do that? 2 downleads? I don't think the Jointenna is weather safe.

thanks,

paul

The PR-9018 has two more reflector and two more director elements. I derived my 9dB estimate from the specs for the UHF section of the Winegard PR-5456. (http://www.winegard.com/offair/antennas/pr5646.htm)

I was guessing that the middle VHF element was a dipole, with a reflector behind it and a director ahead, but again, the picture is just too small to see for sure.
The W-G PR-5646 appears to have 7 directors in front of the UHF active element:
http://www.winegard.com/offair/pdf/Pr-5646.pdf

When I blew up the A-C HBU-22 image, I think I saw something that looked like
a folded dipole UHF active element, with 8 directors in front of it....

Or maybe only 7....too blurry to tell the difference.....

[QUOTE= If I wanted to take the amp out of the circuit, do I need to remove the Mast mounted piece as well as the power injector?

The mast mounted piece is the part with the active electronic components. If you leave it in the signal path without the power being applied, you might possibly see a very strong signal dribble through, but more likely you will see no signal at all pass through it. Both components should be removed. And by the way, make sure that you disconnect the power BEFORE you remove the mast mounted piece. If you remove the amp out at the antenna while power is still being applied, you can damage the power supply (the "wall wart") when you hook up the coax to the balun. I know that from experience ! Of course, this vulnerability may vary from model to model.

I wouldn't spend any money for the 4228 before the filter arrives. You may get this whole thing working on-the-cheap with what you have already bought.

What does TV fool say the relative signal strengths are? The CM will have a front to back ratio of over 20dB, and weaker DTV signal can typically be processed alongside an adjacent DTV signal that is about 26 to 28 dB stronger. I'm pretty sure that the 26 to 28 dB differential is measured in dBmV of signal power. If TV fool furnishes signal strengths in volts rather than in watts, you'll have to do some thinking to figure out if that ratio is plausible.

Should this antenna be able to develop that signal level differential with that antenna at this location? If so, then the next step will be to avoid preamplifier intermodulation with the bandpass filter.

If you can't get your channel 47 signal up to within 26 to 28dB of your channel 46 hitting the back of the antenna, but if you have access to a signal meter, you might point another antenna at the channel 46 transmitter, pad its output down so that it is exactly the same coming from both antennas, and then couple them through a hybrid splitter/combiner and move the antenna targeted at the channel 46 transmitter towards that trnasmitter until the measured, combined channel 46 signal strength reaches its minimum because the two signal sources are 180 degrees out of phase.

Unfortunately, the point at which the channel 46 boxcar is weakest might vary across its band. If I were going to try to phase cancel or phase mitigate a strong UHF signal, I would probably use Winegard PR-9032s, because it might be impossible to get all of the dipole elements of a 4-bay or 8-bay antenna to be in perfect sync with each other.
The Power Insertion Module can be left in the line, but you can't simply remove
power to the Preamp....you must BYPASS/REMOVE the mast-mounted Preamp.
Without power, it doesn't pass any signals....

===============================
Assuming Antenna F/B Ratio of about 20 dB and plugging Radio-Mobile calculated
Path Loss in my spread sheet calculator, Digital CH46 (WBBF-DT) is about
35.4 dB stronger than desired Digital CH47.
ATSC A/74 Receiver "Guidelines" advise the Digital next adjacent should be no
more than 33 dB stronger than the desired Digital.
So local CH46 needs to be suppressed by at least 3 dB.

Next adjacent CH45 (Analog WBBF) is calculated to be 43.8 dB stronger than CH47.
ATSC A/74 Receiver "Guidelines" advise the Analog N-2 adjacent channel should
be no more than 40 dB stronger than the desired Digital.
So local CH45 also needs to be suppressed by at least 4 dB.

This presumes 40-foot roof mounted CM-4228 with HDP-269.

However, actual HDTV performance may not meet A/74 Guidelines, as was
concluded in the following FCC OET tests on STB/HDTVs available in 2005-2006:
http://www.fcc.gov/oet/info/documents/reports/DTV_Interference_Rejection_Thresholds-03-30-07.pdf
http://www.fcc.gov/oet/info/documents/reports/TR-05-1017-ATSC-reception-testing.pdf

==============================
BTW: JoinTenna might suppress CH45 some, but it isn't going to do much against CH46,
cuz it has to have fairly flat frequency and envelope delay response throughout CH47.

===========================
My spreadsheet calculator also predicts about 17.1 dB Fade Margin
(ignoring adjacent channel problem for the moment), which may not be quite
enough to support long term reliability....give or take uncertainties in assumptions....

I've been trying mightily to "calibrate" TVFool by comparing it to
Radio-Mobile, but TVFool estimate for Path Loss is AT LEAST 8 dB higher
for non-LOS (Line-Of-Sight) paths, which would reduce Fade Margin by that amount.

Check TVFool thread for more info....

=============================
A Stagger Tuned Dual Antenna Array would significantly increase F/B Ratio:
http://www.anarc.org/wtfda/stagger.pdf
http://www.matchmaster.com.au/Pdf/01-Comb%20antenna%20NZ%205-06.pdf
(See page 2)

===============================
Here's the Radio-Mobile calculated Profile for WPMT-DT.
Yikes!!! That's quite a hill you're behind...

PS: R-M "RX Relative" (Fade Margin) calculation needs some "adjustments".
Since I only use the Path Loss calculation, I cut corners by assigning 1000 kW ERP
(vice 194 KW, 7.1 dB less) and R-M doesn't include a Cascade Noise Figure calculation....

The Power Insertion Module can be left in the line, but you can't simply remove
power to the Preamp....you must BYPASS/REMOVE the mast-mounted Preamp.
Without power, it doesn't pass any signals.....

But don't have the power module powered up.....unplug it from the wall outlet.

==============================
BTW: JoinTenna might suppress CH45 some, but it isn't going to do much against CH46,
cuz it has to have fairly flat frequency and envelope delay response throughout CH47.

.

I thought the Jointenna was supposed to tune out EVERYTHING other than the channel you have it tuned to?

[QUOTE= If you remove the amp out at the antenna while power is still being applied, you can damage the power supply (the "wall wart") when you hook up the coax to the balun. .

Wow, this would have been good to know a few weeks ago.

I've connected and disconnected the pre-amp on several models recently, without disconnecting or even unplugging the power supplies. I don't think I've done any damage, as the signal still comes through when everything is connected properly.

Perhaps because I've always left a coaxial cable hanging from the balun, and just moved the amp from antenna to antenna?

I thought the Jointenna was supposed to tune out EVERYTHING other than the channel you have it tuned to?
Paul, the Jointenna is a bandpass filter but it is not a rectangular notch for the channel you select. It will not suppress adjacent channels very much. Which is why I wrote that I don't expect the Jointenna to do you that much good against an adjacent channel.

As others have already posted (and IIRC I wrote back in the Washington-baltimore thread), removing the power does NOT result in a bypass of the pre-amp. It instead results in almost no signal coming from the antenna. You must go up to the antenna and bypass the pre-amp from the co-axial cable run. Then aim the CM 4221 north at WPMT-DT and see what stations you get (write them down) & what the signal meter shows for digital UHF 47 (or 47-1) if your ATSC tuner allows you to directly tune to the digital broadcast channel. Do this to baseline your setup before you get into pre-amps, Jointennas, larger antennas, multiple antennas.

PS yes, unplug and disconnect the power supply for the pre-amp before removing the pre-amp at the antenna.

[QUOTE=Tobias Ziegler]

Wow, this would have been good to know a few weeks ago.

I've connected and disconnected the pre-amp on several models recently, without disconnecting or even unplugging the power supplies. I don't think I've done any damage, as the signal still comes through when everything is connected properly.

Perhaps because I've always left a coaxial cable hanging from the balun, and just moved the amp from antenna to antenna?

Yes, the problem is when you hook up the coax directly to the balun while the power is on. Many if not all baluns have a coil on coax side of their circuit, and a coil is practically a direct short for DC. Better quality power supplies might handle it without damage, but in my case, the wall wart died. Now that I think of it, it might also be possible for the balun to be damaged if the power supply can deliver enough current for a long enough time. In any event, power off and you'll have a happier life.

Assuming Antenna F/B Ratio of about 20 dB and plugging Radio-Mobile calculated Path Loss in my spread sheet calculator, Digital CH46 (WBBF-DT) is about 35.4 dB stronger than desired Digital CH47.
ATSC A/74 Receiver "Guidelines" advise the Digital next adjacent should be no
more than 33 dB stronger than the desired Digital.
So local CH46 needs to be suppressed by at least 3 dB.

Next adjacent CH45 (Analog WBBF) is calculated to be 43.8 dB stronger than CH47. ATSC A/74 Receiver "Guidelines" advise the Analog N-2 adjacent channel should be no more than 40 dB stronger than the desired Digital. So local CH45 also needs to be suppressed by at least 4 dB...

However, actual HDTV performance may not meet A/74 Guidelines, as was
concluded in the following FCC OET tests on STB/HDTVs available in 2005-2006:
http://www.fcc.gov/oet/info/documents/reports/DTV_Interference_Rejection_Thresholds-03-30-07.pdf
http://www.fcc.gov/oet/info/documents/reports/TR-05-1017-ATSC-reception-testing.pdf
...


My spreadsheet calculator also predicts about 17.1 dB Fade Margin
(ignoring adjacent channel problem for the moment), which may not be quite
enough to support long term reliability....give or take uncertainties in assumptions.......

I don't think I've ever reliably processed a signal that was more than 30dB weaker than an adjacent one, using either my Radio Shack Accurian (I grabbed four when they closed out on them for $90 each) or my early model Samsung. Does hol_lands know if the Accuran tuner even has a varactor bandpass filter on its input? I suspect either that it does not, or if it does, it is an anemic one, since the so-called signal strength numbers that the Accurian displays on very weak signals can go up substantially if I bandpass filter off strong signals that are even fifty Mhz away from the weak, tuned signal (my weak, unamplified DTV channel 59 could not be processed until I filtered off my strong analog channel 50).

Even if paulsteffano's antenna can develop a D/U ratio of 33dB, and even if his receiver can meet that standard, he still needs a more favorable ratio than that, since the adjacent signal is going to get beaten up in the preamp by 3rd Order IMD. While 3rd Order IMD is about 12 dB stronger on the strong channel itself than it is on the adjacent channel(s), it will still become excessive on the adjacent channel first. In another thread, I pointed out that I have a system with an undesired DTV channel 39 that is 18 to 20 dB stronger than my adjacent DTV channels 38 and 40, and even though my Accurian can process 38 and 40 unamplified, producing so-called "signal strength" numbers around 65% to 70%, as soon as I pass it through a Winegard AP4727 (23 dB gain version of the AP4700/4800), the IMD kills 38 and 40, even though no analog carriers are within ten dB of Winegard's published overload specs and even the strong channel 39 is more than ten dB weaker than the analog carriers.

I'm a little surprised that in an analysis that says a 33dB D/U differential of adjacent digital is acceptable, that the comparable D/U threshold for an N-2 analog signal is 40dB. I have to wonder, as we go from report to report and try to reach conclusions based on the knowledge we accumulate, how often we are comparing apples to oranges. I suspect that an analysis that says that 33dB is the minimum D/U ratio for N-1 digital and 40dB is the minimum D/U ratio for N-2 analog is measuring RMS power within the analog channel 45's 6 Mhz band width, rather than the channel 45 carrier peak, which is all that most of us are outfitted to measure with our field-grade FSMs. If the report was referring to RMS power of the analog channel , then hol_lands should check to see if his channel 45 calculation was for RMS power or for visual carrier peak. I just can't see the channel 45, N-2 analog carrier in this instance contributing anywhere near the degradation that the channel 46, N-1 digital signal will.

Regrettably, the uncertainties that result from being behind a steep hill render this situation a poor one for analysis. Without a spectrum analyzer to measure the received signal strengths, even if he gets his link to work, we won't know which of the inaccurately estimated factors contributed more significantly or less significantly to his satisfactory results, and if he is unsuccessful, we won't know if he missed by an inch or a mile.

I don't think I've ever reliably processed a signal that was more than 30dB weaker than an adjacent one, using either my Radio Shack Accurian (I grabbed four when they closed out on them for $90 each) or my early model Samsung. Does hol_lands know if the Accuran tuner even has a varactor bandpass filter on its input? I suspect either that it does not, or if it does, it is an anemic one, since the so-called signal strength numbers that the Accurian displays on very weak signals can go up substantially if I bandpass filter off strong signals that are even fifty Mhz away from the weak, tuned signal (my weak, unamplified DTV channel 59 could not be processed until I filtered off my strong analog channel 50).

Even if paulsteffano's antenna can develop a D/U ratio of 33dB, and even if his receiver can meet that standard, he still needs a more favorable ratio than that, since the adjacent signal is going to get beaten up in the preamp by 3rd Order IMD. While 3rd Order IMD is about 12 dB stronger on the strong channel itself than it is on the adjacent channel(s), it will still become excessive on the adjacent channel first. In another thread, I pointed out that I have a system with an undesired DTV channel 39 that is 18 to 20 dB stronger than my adjacent DTV channels 38 and 40, and even though my Accurian can process 38 and 40 unamplified, producing so-called "signal strength" numbers around 65% to 70%, as soon as I pass it through a Winegard AP4727 (23 dB gain version of the AP4700/4800), the IMD kills 38 and 40, even though no analog carriers are within ten dB of Winegard's published overload specs and even the strong channel 39 is more than ten dB weaker than the analog carriers.

I'm a little surprised that in an analysis that says a 33dB D/U differential of adjacent digital is acceptable, that the comparable D/U threshold for an N-2 analog signal is 40dB. I have to wonder, as we go from report to report and try to reach conclusions based on the knowledge we accumulate, how often we are comparing apples to oranges. I suspect that an analysis that says that 33dB is the minimum D/U ratio for N-1 digital and 40dB is the minimum D/U ratio for N-2 analog is measuring RMS power within the analog channel 45's 6 Mhz band width, rather than the channel 45 carrier peak, which is all that most of us are outfitted to measure with our field-grade FSMs. If the report was referring to RMS power of the analog channel , then hol_lands should check to see if his channel 45 calculation was for RMS power or for visual carrier peak. I just can't see the channel 45, N-2 analog carrier in this instance contributing anywhere near the degradation that the channel 46, N-1 digital signal will.

Regrettably, the uncertainties that result from being behind a steep hill render this situation a poor one for analysis. Without a spectrum analyzer to measure the received signal strengths, even if he gets his link to work, we won't know which of the inaccurately estimated factors contributed more significantly or less significantly to his satisfactory results, and if he is unsuccessful, we won't know if he missed by an inch or a mile.

I had forgotten about that giant hill when I started all this. I know it's there, becuase it's a favorite place of mine to ride my bike for the great view. Maybe I should just buy a house there!

I had wondered why antenna web's info varied so greatly when I would change the plot by 1/2 mile or less to the east. Thanks for the reminder. Of course realizing this, moving the antenna up or down 15 feet is probably not making much of a difference.

I thought the Jointenna was supposed to tune out EVERYTHING other than the channel you have it tuned to?

Nope. A Jointenna passes several channels above and below the desired channel. The Jointenna will not help intermod from 45/46 being generated in the preamp from getting into 47.

Another approach is to stack two identical antennas horizontally such that they null out 45/46 and add on 47. The stacking distance must be calulated for the exact location and frequency. That plus the front/side ratio if the antennas could get as much as 40 db of isolation between 45/46 and 47.

Because the desired and undesired stations are in opposite directions,
the horizontal distance stacking calculator yields nonsense results.

See above Matchmaster's "Stagger Stacking" on pg 3, vice "Stacking for Gain" on pg 2.

I picked a street address within a block of the I-695/ I-83 intersection and estimated that the rear attack angle of channel 46 is just one degree off the channel 47 target line. The half-wavelength of 645 Mhz is 9.15". The secant of 89 degrees is 57.23. Therefore, the space between the horizontally stacked antennas needs to be about 524" Hmmmm...

That's why it is better to point a second antenna at the Baltimore transmitter, pad it down by 50 dB or so until its channel 46 equals the 46 from the Pennsylvania antenna, and then slide that antenna towards or away from the Baltimore tower until the two signals phase cancel. You should use a variable attenuator like Radio Shack used to make, and each time you move that antenna an inch, wiggle it a little because the output level might vary a little from place to place.

You can put a wire or a string through the boom of the antenna you will be moving to make sliding it easy, or perhaps you can use a moveable, non-penetrating mount.

You will need to be using Yagis with single dipoles and rigid 75 ohm terminator boards, as the loss through a wire lead balun can vary by a couple dB just from the leads flexing.

Or if you want to save the work, Microwave Filter Corp sells a phase shifter that will do that for you. I bought a lowband and a highband model several years ago for a brutal job that the customer then canceled, but they make (or at least, made) a UHF model also. They retailed for $700 each. I think I paid about $450-$500 each.

At this point, before he spends/wastes any more money, paulstefano needs to go on eBay and buy a cheap meter to see just what his channel 47 signal strength is. Someone just bought a digital meter that tunes by frequency for about $20 yesterday. Actually, it is a digital meter that measured peak power within a 250 Mhz bandwidth. I estimate that you would add about 8dB to what the meter produces for a reading. But you'd first have to amplify the signal enough to reach the meter's threshold.

Well,

I appreciate everybody's help. Not one to sit quitely, I decided to do some more experimenting. If anybody cares to comment, I'd love to hear it.

I decided to try to make a notch filter for channel 45 myself. I bought a BNC T connector and some BNC to F adapters. Then I bought a BNC R59 coaxial cable and began to cut. After a bunch of trial and error, I was able to get a stub that seemed to work. I was watching analog 43 on one TV and my Directv Signal meter on another.

My CM 4221 is still on a mast at 40 feet and still connected to my Winegard HDP-269 amp. With the antenna pointed directly at the WPMT tower at 6 degrees azimuth from my house, I am still getting WBFF at 187 degrees. It's not a 100%, but very strong with only occasional dropouts.

I inserted the T connector with notch both before and after the power injector in the line. The result seemed to be about the same.

When I got to the right length, 7.43 centimeters, I completely lost analog 43. On my signal meter, WBFF (Real 46)went to 0, and I saw a quick blip of 25% on WPMT (Real 47), but nothing else.

So, I was able to get rid of WBFF on 46. From the little I know about notch filters, I probably was killing 47. I kept cutting to experiment, and even with a 2 inch piece of wire for a stub, I had suppressed 46, but never saw any more of 47.

Questions: Is this worth pursuing at all? I thought I'd take out the pre-amp (when it's not raining) and try again with another piece of coax. If so, do I need to notch out several stations?

IThat's why it is better to point a second antenna at the Baltimore transmitter, pad it down by 50 dB or so until its channel 46 equals the 46 from the Pennsylvania antenna, and then slide that antenna towards or away from the Baltimore tower until the two signals phase cancel. You should use a variable attenuator like Radio Shack used to make, and each time you move that antenna an inch, wiggle it a little because the output level might vary a little from place to place.


What does it mean to "pad down" a transmitter?

I decided to try to make a notch filter for channel 45 myself. I bought a BNC T connector and some BNC to F adapters. Then I bought a BNC R59 coaxial cable and began to cut.

They actually make type F "Tee" and "X" connectors. Someone sends me a catalog a couple of times a year that list them, but they are scarce.

When I got to the right length, 7.43 centimeters, I completely lost analog 43. On my signal meter, WBFF (Real 46)went to 0, and I saw a quick blip of 25% on WPMT (Real 47), but nothing else.

So, I was able to get rid of WBFF on 46. From the little I know about notch filters, I probably was killing 47. Questions: Is this worth pursuing at all? I thought I'd take out the pre-amp (when it's not raining) and try again with another piece of coax. If so, do I need to notch out several stations?

I think you're wasting your time with a stub filter. We analyzed them here a few years ago, and they were not very sharp, meaning, yes, if it knocks out 46, then it is degrading 47.

And the "elimination" of 46 is an illusion. If your notch lands on the channel 46 pilot carrier, you can probably render channel 46 unprocessable while only reducing its RF power by a couple of dB, especially if your attenuation of it is not linear. If you were in a high stakes situation and you need to throw everything but the kitchen sink at this, you could use a Blonder Tongue MWT-U to put a couple of deep notches into the channel 46 boxcar, but even then, you couldn't reduce its power by more than a few dB that way, either.

I reiterate from my previous post, you need to buy a used meter on eBay. Unfortunately, the one that went recently for $20 was an aberration. Used meters more commonly sell for $150 to $200.

What do you think of this?

http://cgi.*********/SADELCO-VHF-UHF-SIGNAL-LEVER-METER-719D-719DE_W0QQitemZ170128234415QQihZ007QQcategoryZ67882QQssPageN ameZWDVWQQrdZ1QQcmdZViewItem

apparantly I can't link to ebay.

Anyway, if you go there and search "uhg signal meter" the only result is an attractive UHF meter. What do you think of that?

260134234453 $150, 1.5 days. Will sell for twice that.

200125057764 $140, 2 days, 18 hrs, prob good value at $200

Display Max Jrs go for $200-$250, but for some reason, one is now up to $400.

Display Max 3000 is better for your situation, but expect them to sell for $300.

FYI: I posted an update to my DTV Signal Level Calculator spreadsheet which compares
Propagation Prediction results from RADIO-MOBILE vs antennaweb.org and now
includes at attempt at "calibrating" and comparing to TVFool.com on-line calculator:
http://www.avsforum.com/avs-vb/showthread.php?p=10961518&#post10961518

I had forgotten about that giant hill when I started all this. I know it's there, becuase it's a favorite place of mine to ride my bike for the great view. Maybe I should just buy a house there!

I had wondered why antenna web's info varied so greatly when I would change the plot by 1/2 mile or less to the east. Thanks for the reminder. Of course realizing this, moving the antenna up or down 15 feet is probably not making much of a difference.
FYI: I also included detailed calculations for your situation within the
spreadsheet calculator (see sheet 11) just cited above.

Yup, CH45 and CH46 are too strong.

You might be able to suppress them with either the "screen" mentioned above,
and/or temporarily mount the antenna on the North side of the house so that it
attenuates signals coming from the South....and try different heights.

After that, Stagger Stacked antennas has my vote for "most likely to succeed"....

FYI: I also included detailed calculations for your situation within the
spreadsheet calculator (see sheet 11) just cited above.

Yup, CH45 and CH46 are too strong.

You might be able to suppress them with either the "screen" mentioned above,
and/or temporarily mount the antenna on the North side of the house so that it
attenuates signals coming from the South....and try different heights.

After that, Stagger Stacked antennas has my vote for "most likely to succeed"....

does this screen need to be one contiuous piece? I was thinking of using some chicken wire, but the largest width I can find is 4 feet. Can I piece it together, without harming much?

Nope. A Jointenna passes several channels above and below the desired channel. The Jointenna will not help intermod from 45/46 being generated in the preamp from getting into 47.

Another approach is to stack two identical antennas horizontally such that they null out 45/46 and add on 47. The stacking distance must be calulated for the exact location and frequency. That plus the front/side ratio if the antennas could get as much as 40 db of isolation between 45/46 and 47.
Would it make sens to get a Jointenna for something below 47, so that it would also attenuate 45 and 46, but not degrade 47?

I think you're wasting your time with a stub filter. We analyzed them here a few years ago, and they were not very sharp, meaning, yes, if it knocks out 46, then it is degrading 47.

And the "elimination" of 46 is an illusion. If your notch lands on the channel 46 pilot carrier, you can probably render channel 46 unprocessable while only reducing its RF power by a couple of dB, especially if your attenuation of it is not linear. If you were in a high stakes situation and you need to throw everything but the kitchen sink at this, you could use a Blonder Tongue MWT-U to put a couple of deep notches into the channel 46 boxcar, but even then, you couldn't reduce its power by more than a few dB that way, either.

.

If I read holl_ands report right, then the overloading past what 47 should tolerate is only 2.3 db for channel 46 and 3.8 db for channel 45. That should easy to trap out with almost any equipment properly tuned right?

does this screen need to be one contiuous piece? I was thinking of using some chicken wire, but the largest width I can find is 4 feet. Can I piece it together, without harming much?
No it does not need to be one continuous piece so long as you don't have gaps in the screen.

Have you tried getting WPMT-DT yet without the pre-amp in the signal path? Do you get WBFF-DT Fox 45 (DT=46) with the pre-amp installed?

No it does not need to be one continuous piece so long as you don't have gaps in the screen.

Have you tried getting WPMT-DT yet without the pre-amp in the signal path? Do you get WBFF-DT Fox 45 (DT=46) with the pre-amp installed?

Sounds like you have a typo there. You mention 2 separate situations.

WITH the pre-amp installed I get WBFF-DT strong, although the antenna is pointed 180 degrees away from the tower.

WITHOUT the pre-amp...Not sure, I plan to try that tonight.

Given holl_ands report, doesn't it seem like a dual channel trap would work? I think the Jointenna still has a shot, as it will degrade both 46 and 45 a little, maybe enough to knock of 2.3 and 3.8 db respectively.

If I read holl_ands report right, then the overloading past what 47 should tolerate is only 2.3 db for channel 46 and 3.8 db for channel 45. That should easy to trap out with almost any equipment properly tuned right?

These projections incorporate more precision than is warranted by the accuracy of our data. Hol_lands recommendations of D/U ratios are based on the assumption that a tuner meets a recommended performance level, but he and I have both warned that many, if not most, tuners do not perform that well. Further, the 2.3 dB channel 46 reduction prescription is only for instances with no subsequent preamplification. Any preamplification will cause intermodulation distortion, and a signal that is 30dB weaker than the one adjacent to it will be degraded by even the weak intermodulation distortion that will be developed by a quality amplifier that is being driven well below its benchmark overload conditions.

You really need to determine that you have enough channel 47 signal to salvage if processed properly before going any further.

We must also bear in mind that long distance, weak signals are more sensitive to changes
in propagation conditions (e.g. refractive index) and consequently the calculated R-M
signal levels represent some sort of AVERAGE signal strength, which will be significantly
LOWER as the signal suffers from both seasonal changes, and also multipath fades.

On the other hand, the local signals remains pretty much rock steady...

For long term reliability, it wouldn't hurt to factor in 10 dB for "conservative engineering".
So the amount of CH45/46 suppression for real-world environment is
perhaps 10 dB more than lab measurements.

These projections incorporate more precision than is warranted by the accuracy of our data. Hol_lands recommendations of D/U ratios are based on the assumption that a tuner meets a recommended performance level, but he and I have both warned that many, if not most, tuners do nort perform that well. Further, the 2.3 dB channel 46 reduction prescriotion is only for instances with no subsequent preamplification. Any preamplification will cause intermodulation distortion, and a signal that is 30dB weaker than the one adjacent to it will be degraded by even the weak intermodulation distortion that will be developed by a quality amplifier that is being driven well below its benchmarl overload conditions.

You really need to determine that you have enough channel 47 signal to salvage if processed properly before going any further.
In the spreadsheet calculator, I included a derivation of how strong undesired
signals could be for the maximum SFDR (Spurious Free Dynamic Range),
wherein the intermod products are no higher than the thermal noise floor.
When pointing North, the W-G HDP-269 was calculated to be operating with
undesired signals 10 dB BELOW this point, hence IMD desensitization "should"
not be a problem (with the CM-4228).

CM-4221 will be somewhat worse...
C-M specs for F/B Ratio are 4 dB less, although it looks more like 10 dB difference in:
http://www.hdtvprimer.com/ANTENNAS/comparing.html

Re. Stagger Stacked Antenna choice: A pair of Corner Yagis is probably better than
a pair of back-to-back CM-4221's....but the latter is cheaper and hence worth trying....

Because the desired and undesired stations are in opposite directions,
the horizontal distance stacking calculator yields nonsense results.

See above Matchmaster's "Stagger Stacking" on pg 3, vice "Stacking for Gain" on pg 2.

Correct. I did not analyze the directions closely before I wrote the response. Stagger stacking is the answer.

Would it make sens to get a Jointenna for something below 47, so that it would also attenuate 45 and 46, but not degrade 47?

If you wanted to try that trick you'd need a Jointenna for channel 48 or 49. Even then that's unlikely to be effective.

Update:

I removed the HDP-269 from the line and I retained 43 Analog very cleary, if not as cleary as I had it with the amp. WBFF-DT is not showing up on my Directv Signal meter, nor is WPMT-DT. I am, strangely picking up intermittently, WMAR-DT.

So, does everybody's recommendations still stand?

If I am to go the stacked antenna route, what's my best options? Given, I already have a CM 4221, I see it like this.

1. Stack 2 4221 antennas (most affordable)
2. Buy a 4228, try it alone, if not stack it with the 4221 (not sure if this will work)
3. Buy 2 Yagis and basically start over (Model recommendations would be appreciated)

Finally, is everybody convinced that attenuating 45 and 46 with a notch, a trap or bandpass filter is worthless?

thanks again for all your help.

paul

So, does everybody's recommendations still stand?

If I am to go the stacked antenna route, what's my best options?

Finally, is everybody convinced that attenuating 45 and 46 with a notch, a trap or bandpass filter is worthless?

thanks again for all your help.

paul

Notch or traps are almost worthless. A bandpass filter will help. It is easier than stagger stacking, but more expensive.

Stagger stacking a pair of 4221's will require building a custom standoff for one of the 4221's. A pair of Yagis will be easier to construct because the boom can be drilled to accommodate the needed offset.

The magic dimensions for stagger stacking on channel 47 are 4 3/8" antenna offset and 3 5/8" more RG-6 for the antenna closer to York than the further antenna.

1. The Stagger Stacked Antenna Array ensures that the two signals going into the combiner
are OUT-OF-PHASE with each other. It does this by mounting the antennas so that the antenna
feed points are a quarter-wavelength apart (for the undesired channel) and there is another
quarter-wavelength difference between the two cables.
[And note the adjustment for velocity factor in the cables.]
But the nulling bandwidth is very limited....

2. But that's not the only configuration:
If two CM-4221's are mounted back-to-back, measure the physical distance between
the two antenna feed points, figure how much of a wavelength that is (say 0.4 lamda)
for the undesired channel and then make the two interconnecting cables
so that the OVERALL DIFFERENCE is a multiple of one-half lamda
On one of the balun transformers, you'll need to flip the pair connecting to one
of the antennas anyway to make sure they're out-of-phase.
[Watch signal strength indicator while watching CH46.]
Obviously, a DIY system would need an RF attenuator to reduce the signal level
for the (unamplified) antenna pointed to the local stations....which isn't easy to adjust...

3. A similar arrangement with two (more or less) arbitrarily located antennas can
be used in a phase canceling antenna system:
http://pages.cthome.net/fmdx/phase.html
http://www.geocities.com/toddemslie/phase_cancellation.htm
Electrical components are used to selectively insert phase shift delays and adjust signal levels.
Off-the-shelf Phase Cancelers are available---but mostly for Amateur Radio bands....

==============================
The advantage of all of these approaches is the the signal coming from
the desired direction is unaffected by any filtering processes.
The only degradation is due to whatever additional noise and multipath is
picked up by the UNAMPLIFIED and ATTENUATED antenna pointing
in the opposite direction...presumably a small effect....

Since the nulling bandwidth is very limited, it would only suppress the upper
portion of CH46 without adversely affecting CH47, and a filter would still be
needed to attenuate CH45 (and lower part of CH46).

Hope this helps to understand the options....
But it would be difficult for a DIY project if you can't measure signal levels....

===============================
FWIW: My Sylvania OTA STB and DTA-5000 "Smart Antenna" supposedly
searches all 16 compass headings and picks the one with the "best" performance.
But it's mostly a low gain beam former, rather than directing nulls towards
undesired signal directions---like a true Adaptive Antenna Array would do....

I look forward to a new generation of "Smart Antennas"....

But it would be difficult for a DIY project if you can't measure signal levels....

I don't mean to sound flippant here, but if paulstefano still, "wants to play, he has to pay". None of the advice given in the last few pages of posts could possibly be worked into a real world solution without a signal meter. Ideally, he would have a spectrum analyzer, which, if bought on eBay, would cost $500 to $700 for a 1 Mhz scope with 80dB of vertical scale and that probably cost about $3,000 new, but if he had a lot of wearwithall, he could probably pull this off with a $200 digital readout FSM. But when the antenna being tweaked is on a 40 foot mast, fine tuning through trial and error can be hell.

In the spreadsheet calculator, I included a derivation of how strong undesired signals could be for the maximum SFDR (Spurious Free Dynamic Range), wherein the intermod products are no higher than the thermal noise floor. When pointing North, the W-G HDP-269 was calculated to be operating with undesired signals 10 dB BELOW this point, hence IMD desensitization "should" not be a problem (with the CM-4228)....

But the only published specs for the HDP-259's intermodulation products are those found in Winegard's latest "funny numbers" preamplifier table, which says that the "maximum total input voltage" is 350,000 total microvolts. What are total microvolts? To keep this in simple digits for exposition's sake, if I impress five volts across a one ohm resistor, I sink five amps and develop 25 watts of output, but if I impress one volt across each of five one ohm resistors, I arguably have five total volts, but I only develop only 5 watts. Why would I use "total volts" to express a limit that does not remain constant with different aggregations of voltages?

The new HDP-259 specs table is eerily similar to the earlier Winegard tables that have been vilified in this forum previously. You know, the one where they used to say that the ratings were for five, equal strength channels, but then dropped that qualifier from later printings, and sometimes they called the maximum input/output levels the levels at which the analog signals incurred 5% sync compression, but then later, said that those exact same signal levels were the ones at which -46 dBc of cross modulation took place.

Winegard has variously claimed that the AP4700 can handle inputs of 90,000 microvolts (about 39 dBmV), meaning it would output 56 dBmV after amplifying the signals by 17 dB, and that the AP4800 can handle inputs of 30,000 (about 29.5 dBmV), meaning it similarly would output about 57.5 dBmV under those conditions without overloading. And now, in the HDP-259's table, which is similarly formatted and is sans channel load parameter, it will allow an input of 350,000 microvolts, resulting in an output of 63 dBmV without overloading? I have three things to say about that claim:

1. Ho-ho-ho!

2. Hee-hee-hee!

3. Ha-ha-ha!

I should stop buying Blonder Tongue BIDA distribution amplifiers for $400 each and just use Winegard preamps in the same applications, instead.

A few weeks ago, I mentioned that the Winegard AP4727, which is a 22 or 23 dB gain mongrel brother of the AP4700 and AP4800, couldn't hold a candle to the Channel Master OSD 0065, which has the identical gain. when used in the same application. The Winegard AP4727 beat some weaker, adjacent digital channels into paste, yet, if you simply started with the assumption that a Winegard preamp could amplify even one digital channel to 57 dBmV without the IMD being excessive (what is our arbitrary benchmark for 3rd Order IMD? Perhaps -40 dBc? I don't think I've seen a figure in any manufacturer's published literature), and then figure that the adjacent channel 3rd order IMD is 12 dB below that, and then recalculate based on the fact that my strong adjacent digital input signal, at no more than 10 dBmV, was at least 24 dB below that maximum input level (57 dBmV out minus 23 dB gain = 34 dBmV max input), and therefore calculate that the 3rd Order IMD must be down by 72 dB (according to various technical literature, dropping the output level by one dB reduces the 3rd Order IMD by 3 dB, thus 24 dBmV power reduction results in 72 dB reduction in 3rd Order IMD), which makes it below the thermal noise floor. So if it is below the thermal noise floor, why can't any of my receivers lock onto the weaker adjacent signals after the AP4727 has "gently" amplified them? And I tried two different AP4727s, with the same result.

I just ordered a Winegard HDP-259. I will put it to "the test". I will feed it a channel 38 and 40 that are about 30 dB below the local channel 39 and then see how it performs at different power levels. I will also compare it to some 10 dB and 15 dB cable TV amps that I can buy on eBay for $10 to 15 each. I will wager that the HDP-259 doesn't come close to performing satisfactorily under the relatively extreme signal differentials I feed into it, and I doubt that it outperforms the $10 cable TV amplifiers. I used a couple of them as preamps recently and they worked great.

What are you predicting the signal strength of the channel 46 and 47 DTV signals to be?

I don't mean to sound flippant here, but if paulstefano still, "wants to play, he has to pay". None of the advice given in the last few pages of posts could possibly be worked into a real world solution without a signal meter. Ideally, he would have a spectrum analyzer, which, if bought on eBay, would cost $500 to $700 for a 1 Mhz scope with 80dB of vertical scale and that probably cost about $3,000 new, but if he had a lot of wearwithall, he could probably pull this off with a $200 digital readout FSM. But when the antenna being tweaked is on a 40 foot mast, fine tuning through trial and error can be hell.

I'll be honest, this is getting a little more expensive than I thought. My whoe reason to start out doing this was to stop paying Directv for the NFL Sunday Ticket. They charge $250 and make you order ALL games. Since I only want to watch the Philadelphia Eagles, I thought I'd try to pick up an OTA broadcast. Along those lines, can somebody with Google Earth tell me if I would have a shot at the Philly Stations with a bigger antenna? The towers are 55 degrees from the WPMT tower from my location, and that's also 55 degrees away from that big hill!

Anyway, to get WPMT right, I would need to spend much more than $250. I think I may just watch the next 2 seasons in Analog on channel 43, and be done with it.

paul

...can somebody with Google Earth tell me if I would have a shot at the Philly Stations with a bigger antenna?
andy.s.lee has a terrific app for Google Earth that shows transmitter locations, and another one that shows signal strength [i.e., coverage area and antenna suggestions]; they are being discussed here:
http://www.avsforum.com/avs-vb/showthread.php?t=821480

Since I only want to watch the Philadelphia Eagles, I thought I'd try to pick up an OTA broadcast. Along those lines, can somebody with Google Earth tell me if I would have a shot at the Philly Stations with a bigger antenna?


Certainly not WTXF (Fox). Their digital transmitter is pretty low and even local people have trouble with it. You're deep fringe for Philly anyway.

Anyway, to get WPMT right, I would need to spend much more than $250. I think I may just watch the next 2 seasons in Analog on channel 43, and be done with it.

Unfortunately, WBFF-DT is staying on 46 and WPMT on 47, so come 2009, you have the same problem. Unless the Eagles move to a different channel. Plenty of time to work on it, though. Maybe you could move so the giant hill blocks WBFF instead of WPMT :-)

And if you enable display of ALL analog and digital stations in GoogleEarth,
you'll quickly see that you are SURROUNDED with stations all fighting for a
limited number of channel positions....and causing adjacent channel problems.

The TVFool.com charts list all potentially viewable stations....where the
bottom of the list is somewhere between iffy and fergetit.

WTXF-DT (FOX), 85 miles away in Philly is on CH42...
but so is WMPT-DT (PBS) and only 28 miles away.

>>> On analog 43, I get a VERY clear signal, no jumping or skipping,
>>> but there is a fuzzy grain to the picture.

"Fuzzy grain" sounds like snow, which means a poor signal/noise ratio.

http://www.kyes.com/antenna/interference/interferencedex.html
http://www.kyes.com/antenna/interference/tvibook.html

Does someone make a peaky single channel yagi for UHF? Let the antenna
do some bandpass filtering. Looks like this would work well for VHF-LO,
less well for VHF-HI, but probably not for UHF?
http://www.hdtvprimer.com/ANTENNAS/WadeSCY.html

Or... find an antenna with a better front/back ratio. Is there a front/back
spec for the XG91? Looks good on the simulated plots:
http://www.hdtvprimer.com/ANTENNAS/XG91.html
Same for DAT75:
http://www.hdtvprimer.com/ANTENNAS/DAT75.html

>> weaker DTV signal can typically be processed alongside an adjacent DTV
>> signal that is about 26 to 28 dB stronger

CRC test says 37.1 dB for the Samsung. Looks like they didn't
do this test for Linx or LG.

>> channel 46 boxcar

"boxcar" ?

> Maybe you could move so the giant hill blocks WBFF instead of WPMT :-)

Do you have the antenna pointed up, just above the top of the hill?

Perhaps try a different tuner/demodulator?

"boxcar" ?
When a spectrum analyzer is set on moderately fine resolution (say, 300 Khz), the waveform is often described as boxcar shaped. When it is set on a wider resolution (commonly, 3 Mhz), it is more accurately described as haystack shaped.

>> weaker DTV signal can typically be processed alongside an adjacent DTV
>> signal that is about 26 to 28 dB stronger

CRC test says 37.1 dB for the Samsung.

Here is what the FCC is using for D/U reference levels in determining whether to allow some DTV allotment changes

FCC 73.623 DTV applications and changes to DTV allotments. (http://www.hallikainen.com/FccRules/2007/73/623/)
Revised as of July 5, 2007


The threshold levels at which interference is considered to occur are:
D/U Ratio
Co-channel:
DTV-into-analog TV +34
Analog TV-into-DTV +2
DTV-into-DTV +15
First Adjacent Channel:
Lower DTV-into-analog TV −14
Upper DTV-into-analog TV −17
Lower analog TV-into-DTV −48
Upper analog TV-into-DTV −49
Lower DTV-into-DTV -28
Upper DTV-into-DTV −26
Other Adjacent Channel (Channels 14–69 only)
DTV-into-analog TV, where N = analog TV channel
and DTV Channel:
N–2 −24
N+2 −28
N–3 −30
N+3 −34
N–4 −34
N+4 −25
N–7 −35
N+7 −43
N–8 −32
N+8 −43
N+14 −33
N+15 −31

I'm not familiar with the CRC Samsung test to which Konrad2 has alluded, but before anyone shells out another two or three hundred dollars, be forewarned that, 1) any ratio would probably vary somewhat with frequency, and, 2) any receiver that significantly outperforms the field by one measure may underperform it by another.

>>>
Does someone make a peaky single channel yagi for UHF? Let the antenna
do some bandpass filtering. Looks like this would work well for VHF-LO,
less well for VHF-HI, but probably not for UHF?
http://www.hdtvprimer.com/ANTENNAS/WadeSCY.html

A1: Notice above Lo-VHF antennas have a "Q" (ratio of bandwidth to op. freq)
of about 10, which barely covers one channel width.
For Hi-VHF, "Q" is also about 10, which now covers about 3 channels.
For UHF, a "Q" of 10 would range from 8-13 channels....
consistent with Blonder-Tongue BTY series, Fracarro et. al. super Yagis.

Or... find an antenna with a better front/back ratio. Is there a front/back
spec for the XG91? Looks good on the simulated plots:
http://www.hdtvprimer.com/ANTENNAS/XG91.html
Same for DAT75:
http://www.hdtvprimer.com/ANTENNAS/DAT75.html

A2: Antennas Direct (as well as Funke "equivalent"), claim 28 dB F/B for 91XG
and 27 dB for 43XG. But in keeping with their usual spec practice, this may be
for the best channel, perhaps along the best, more or less rear facing azimuth....
Nonetheless, the 91XG has higher gain than CM-4228 and hence higher F/B Ratio.

>> weaker DTV signal can typically be processed alongside an adjacent DTV
>> signal that is about 26 to 28 dB stronger
CRC test says 37.1 dB for the Samsung. Looks like they didn't do this test for Linx or LG.

A3: Below jpg is Fig 15-1 from recent FCC Office of Eng'n'g Tech. test of 8 HDTVs:
http://www.fcc.gov/oet/info/documents/reports/DTV_Interference_Rejection_Thresholds-03-30-07.pdf
which supplements earlier sensitivity and multipath tests:
http://www.fcc.gov/oet/info/documents/reports/TR-05-1017-ATSC-reception-testing.doc
Fig 15-1 shows fairly good performance against adjacent digital channels,
but unexpectedly some HDTVs (shhhh, no names please) were even
more sensitive to interference on the NEXT adjacent channels (N+2, N-2).
Note channels further away were ALSO causing interference for some HDTVs.
The "humps" at N+7 (and probably also N-6) are due to oscillator image effects.
BTW, out of 30 HDTVs tested, ALL had single conversion tuners.

Do you have the antenna pointed up, just above the top of the hill?

A4: The profile chart greatly exaggerates the terrain height.
The elevation angle is negligible--less than a degree.

Perhaps try a different tuner/demodulator?

A5: He has two already.

Sorry if this doesn't really help paulstefano's situation...
but roaming around on and off topic is what we do best....

CRC (Communications Research Centre, Canada) conducted tests on
three PROTOTYPE ATSC Receivers:
http://www.crc.ca/en/html/crc/home/research/broadcast/rtnt

One of these is an early Linx (now Micronas) that may or not have gone into production.

The LG/Zenith "5th Gen" Receiver was an early PROTOTYPE.
It had problems with some of the multipath test ensembles, that may
or may not have been fixed in production units.

The Samsung "Gemini" ATSC Processor chip was used with an off-the-shelf ALPS tuner module.
(I think "Gemini" was code name for ATI Xillion chip, now found in the DTB-H260F.)
(Or whatever is found inside the Samsung version of the D* Receivers.)

>> Here is what the FCC is using for D/U reference levels in determining
>> whether to allow some DTV allotment changes

One might hope that the FCC is being very conservative. (Although I
read somewhere a claim that the FCC managed to get the required
field strength wrong by 56 dB. If true they might get other things
wrong as well.)

>> I'm not familiar with the CRC Samsung test to which Konrad2 has alluded,

http://www.crc.ca/en/html/crc/home/research/broadcast/rtnt

>> but before anyone shells out another two or three hundred dollars, be
>> forewarned that, 1) any ratio would probably vary somewhat with frequency,
>> and, 2) any receiver that significantly outperforms the field by one
>> measure may underperform it by another.

True. And in the real world the tuner/demod will be fighting multiple
problems at once which might degrade the ability to fight the D into D
interference.

>>> On analog 43, I get a VERY clear signal, no jumping or skipping,
>>> but there is a fuzzy grain to the picture.

"Fuzzy grain" sounds like snow, which means a poor signal/noise ratio.

http://www.kyes.com/antenna/interference/interferencedex.html
http://www.kyes.com/antenna/interference/tvibook.html

Does someone make a peaky single channel yagi for UHF? Let the antenna
do some bandpass filtering. Looks like this would work well for VHF-LO,
less well for VHF-HI, but probably not for UHF?
http://www.hdtvprimer.com/ANTENNAS/WadeSCY.html

Or... find an antenna with a better front/back ratio. Is there a front/back
spec for the XG91? Looks good on the simulated plots:
http://www.hdtvprimer.com/ANTENNAS/XG91.html
Same for DAT75:
http://www.hdtvprimer.com/ANTENNAS/DAT75.html

>> weaker DTV signal can typically be processed alongside an adjacent DTV
>> signal that is about 26 to 28 dB stronger

CRC test says 37.1 dB for the Samsung. Looks like they didn't
do this test for Linx or LG.

>> channel 46 boxcar

"boxcar" ?

> Maybe you could move so the giant hill blocks WBFF instead of WPMT :-)

Do you have the antenna pointed up, just above the top of the hill?

Perhaps try a different tuner/demodulator?


Wow, after looking at this link what I have on WPMT Analog is definitely poor signal. It's "clear" in so much as it doesn't ghost, or jump, but it looks alot like the sample of "poor signal".

Given that, Does anybody think I should just try an antenna with more gain, like the CM 4228?

Wow, after looking at this link what I have on WPMT Analog is definitely poor signal. It's "clear" in so much as it doesn't ghost, or jump, but it looks alot like the sample of "poor signal".

Given that, Does anybody think I should just try an antenna with more gain, like the CM 4228?

Well. given that your analog channel 43 and digital channel 47 travel the same path, their degradation should be similar. From your description, the peak power level of the visual carrier of the analog channel 43 coming off the antenna might be between -5dBmV and -15dBmV. What do hol_land's models (Radio Mobile and TV fool) predict for relative strength of 43 and 47 at this site? From that, we can more reliably estimate your present channel 47 RMS power level to see if it is suitable for further processing or needs to be increased..

Again, I reiterate the concern that I expressed earlier, which is that in calculating signal levels using any of these evolving models, we must make sure that we know if the analog signals are expressed in RMS power or peak visual carrier power. I haven't followed their development enough to have any idea.

>>>> I've connected and disconnected the pre-amp on several models recently

Does this imply that you have more than one amp sitting around to play with?
If so, once the jointenna arrives try a higher gain amp, with the amp
"downstream" of the jointenna so that the jointenna eliminates most
stations and hopefully prevents the amp from overloading.

>>> You should use a variable attenuator like Radio Shack used to make

Here's one
http://www.antennasdirect.com/attenuator.html
(Ignore the nonsense about an attenuator helping with multipath.)

>> What does it mean to "pad down" a transmitter?

attenuate

>> I removed the HDP-269 from the line and I retained 43 Analog very cleary,
>> if not as cleary as I had it with the amp.

>> Wow, after looking at this link what I have on WPMT Analog is definitely
>> poor signal. It's "clear" in so much as it doesn't ghost, or jump, but it
>> looks alot like the sample of "poor signal".

>> Given that, Does anybody think I should just try an antenna with more gain,
>> like the CM 4228?

An antenna with more gain will help reduce snow on 43 Analog. As will removing
any splitters if you are using any. An amp with a lower noise figure will help,
although one better than your HDP-269 will be expensive. A higher gain amp
should help if you can keep it from overloading.

An antenna with more gain might help with digital 47. If the main problem with
47 is interference from 46, you want to try and reduce the amount of 46 that
the antenna picks up. The station list a few messages back doesn't include
angles, but I presume that 46 is in the opposite direction from 47? So you want
high gain, and you also want a high front-to-back ratio. Get the exact angles
and then look at the radiation patterns for various high gain UHF antennas.
Figure out what direction 46 will be with the 0 dB lobe pointing at 47. Find
the antenna with the smallest gain pointing at 46. A null (plot curves in to the
center of the chart) would be ideal.

http://www.hdtvprimer.com/ANTENNAS/XG91.html
http://www.hdtvprimer.com/ANTENNAS/DAT75.html
http://www.hdtvprimer.com/ANTENNAS/w8800.html
http://www.hdtvprimer.com/ANTENNAS/DB8.html
http://www.hdtvprimer.com/ANTENNAS/cm4228.html

>>> Assuming Antenna F/B Ratio of about 20 dB
>>> ...
>>> So local CH46 needs to be suppressed by at least 3 dB.

> Antennas Direct (as well as Funke "equivalent"), claim 28 dB F/B for
> 91XG and 27 dB for 43XG. But in keeping with their usual spec practice,
> this may be for the best channel, perhaps along the best, more or less
> rear facing azimuth.... Nonetheless, the 91XG has higher gain than
> CM-4228 and hence higher F/B Ratio.

So a different antenna might be enough.

>>>> I don't think the Jointenna is weather safe.

Experiment on a nice day. :-)

If you find a solution that requires a Jointenna, attenuator,
or similar device to be near the antenna, they sell weatherproof
boxes for that purpose.

I have a Channel Master 4228 UHF antenna hooked up to a Channel Master 7777 Pre-Amp.

For a while, I only had the antenna hooked up to one room (Den), but last year, I put in a splitter near the grounding block and ran a second line from the splitter to a line coming from my DirecTV where I diplexed the signal and split it again inside to two lines... one going to my SD DirecTiVo and a Series 2 Stand-Alone TiVo in the Living Room. I was unable to plug my Channel Master 7777 pre-amp in, but I was able to pick all the stations up anyway... so no big deal. However...

The other day I was out running new RG6 runs for when DirecTV installs my new 5-LNB dish and decided to run a new dedicated line for the Living Room that WAS diplexed... but when I plug it into the splitter, I don't get reception in that Living Room... nor do I get reception in the other Den. I unplug it, and I get reception in the Den... I unplug the Den, I get reception in the Living Room.

Any suggestions as to what my problem is, and how to correct it?

~Alan

What do hol_land's models (Radio Mobile and TV fool) predict for relative strength of 43 and 47 at this site? .

I don't completely understand the numbers so I'm not sure where to look in the file.?

I was unable to plug my Channel Master 7777 pre-amp in, but I was able to pick all the stations up anyway... so no big deal. However...


You need to keep track of where the DC power is going, and make sure it is correct.

If I understand your current situation, you've got



Antenna -- preamp -- splitter -- DEN
|-- LIVING ROOM

and the DirecTV wiring is completely separate. You've got no DC power at all, so your pre-amp is acting as an attenuator instead of an amplifier. That it works at all with one side disconnected is basically accident.

Install the 0747 power injector before the splitter, if you can. If you can't do that, and the splitter is power-pass on one port (usually indicated by a line on the splitter label from one of the outputs to the input), plug the 0747 power injector into the coax coming off of that port. If it is power-pass on all ports, plug the injector into the coax coming off of either port, and install a DC blocker on the other port. If it doesn't pass power at all, you need a new splitter.

Well. given that your analog channel 43 and digital channel 47 travel the same path, their degradation should be similar. From your description, the peak power level of the visual carrier of the analog channel 43 coming off the antenna might be between -5dBmV and -15dBmV. What do hol_land's models (Radio Mobile and TV fool) predict for relative strength of 43 and 47 at this site? From that, we can more reliably estimate your present channel 47 RMS power level to see if it is suitable for further processing or needs to be increased..

Again, I reiterate the concern that I expressed earlier, which is that in calculating signal levels using any of these evolving models, we must make sure that we know if the analog signals are expressed in RMS power or peak visual carrier power. I haven't followed their development enough to have any idea.
Calculated signal levels at input of Preamp, assuming CM-4228 pointed North:
CH43 (A-WPMT): -74.1 dBm (-25.3 dBmV) with 62.2 dBuV/m E-Field level.
CH47 (WPMT-DT): -65.4 dBm (-16.6 dBmV)
So DTV is calculated to be significantly stronger than Analog.
And PEAK DTV signal level is 7+ dB higher still.....

PEAK is used for Analog and AVERAGE across DTV bandwidth for Digital.
This applies to the ERP transmitter power allotments, ATSC sensitivity specs,
Analog and Digital Class A/B reception criteria and test equipment measurements.

The fol. Potomac and Boonton App. Notes explain conversions for DTV
when using older Analog meter:
http://www.pi-usa.com/pdf/dtva.pdf
http://www.boonton.com/2002/pdf/AN50.pdf
see also "Television Field Strength: Prediction and Measurement"
http://www.pi-usa.com/support.htm

When considering Preamp overload, we have to be worried most about PEAK
voltage excursions, because those are the ones that cause infrequent data errors.
In the OVERLOAD Calculation spreadsheet, I noted that the Peaks of a
DTV signal are 7 +/- 1 dB above the calculated average signal levels.

You need to keep track of where the DC power is going, and make sure it is correct.

If I understand your current situation, you've got



Antenna -- preamp -- splitter -- DEN
|-- LIVING ROOM

and the DirecTV wiring is completely separate. You've got no DC power at all, so your pre-amp is acting as an attenuator instead of an amplifier. That it works at all with one side disconnected is basically accident.

Actually, I have the line running into the Den plugged into a Surge Protector, and then into the power injector. I only had the power injector unplugged when I had the line into the Living Room diplexed as it interefered with the DirecTV multi-switch... and it worked fine without it. It still works fine with it unplugged as long as ONLY ONE LINE is hooked up to the splitter... but it doesn't work at all (plugged or unplugged) if both are hooked up to the splitter.

Install the 0747 power injector before the splitter, if you can. If you can't do that, and the splitter is power-pass on one port (usually indicated by a line on the splitter label from one of the outputs to the input), plug the 0747 power injector into the coax coming off of that port. If it is power-pass on all ports, plug the injector into the coax coming off of either port, and install a DC blocker on the other port. If it doesn't pass power at all, you need a new splitter.

I can't install the power injector before the splitter as I have no way to get power to it under the house. As far as the splitter that I'm using, I have no idea regarding the power-pass capabilities (I'll try to look into it when I get home from work), but I swapped it with another splitter (same type though) and a four-way power splitter... and still no good.

DC Blocker?

Also, what I find so strange regarding the whole thing is that I had it working fine when I had the antenna diplexed to the living room... yet I do a dedicated line and everything screws up. You'd think it would be the other way around...

~Alan

I have a grounding question. If I have an outdoor antenna with a downlead into an attic, then back out of the attic and into the basement, is grounding it at the basement enough?

thanks,

paul

Okay,

I've decided to find out if my situation will be improved by more antenna gain, so I need to decide between 2 models, the Wingard PR 8800 or the CM 4228.

The PR 8800 can be had locally, for $63 and, I can avoid shipping charges.

All the C2 4228 dealers charge $25 or more to ship that giant box, making the price $75-$80.

So, is there THAT much of a difference between the two?

Checking hdtvprimer.com, the PR-8800 has about 1dB less gain at ch 47 and has significantly larger sidelobes than the CM-4228. In your very marginal situation, you need every DB and every bit of directionality you can get.

> I've decided to find out if my situation will be improved by more
> antenna gain, so I need to decide between 2 models, the Wingard
> PR 8800 or the CM 4228.

> So, is there THAT much of a difference between the two?

A year ago I was deciding between these two. I waded through this entire
thread. Summary:

CM 4228 is steel and weighs more than the mostly aluminum Winegard PR-8800.

CM 4228 has higher wind load than PR-8800. Consumer TV rotors have problems
with the CM 4228. If you want to use the CM 4228 with a rotor look into
a heavy duty ham rotor.

PR-8800 has more gain than CM 4228 below channel 24-28.
CM 4228 has more gain than PR-8800 above channel 24-28.
CM 4228 is said to be usable for VHF-HI despite the poor frequency response.
http://www.hdtvprimer.com/ANTENNAS/comparing.html

Simulations show different radiation patterns, so one or the other might be
better for a particular situation. I have no idea how accurate the
simulations are.

Some people say that CM quality has gone downhill, and is now lower than
Winegard.

I picked the PR-8800 and it works well. PR-8800 works okay for VHF-HI.
I can't compare it with the 4228 since I don't have a 4228.

Have you ruled out the Yagis such as the XG91 and DAT75 ? I would
think that they would be preferred over the 8 bays for your situation?

> I've decided to find out if my situation will be improved by more
> antenna gain, so I need to decide between 2 models, the Wingard
> PR 8800 or the CM 4228.

> So, is there THAT much of a difference between the two?

A year ago I was deciding between these two. I waded through this entire
thread. Summary:

CM 4228 is steel and weighs more than the mostly aluminum Winegard PR-8800.

CM 4228 has higher wind load than PR-8800. Consumer TV rotors have problems
with the CM 4228. If you want to use the CM 4228 with a rotor look into
a heavy duty ham rotor.

PR-8800 has more gain than CM 4228 below channel 24-28.
CM 4228 has more gain than PR-8800 above channel 24-28.
CM 4228 is said to be usable for VHF-HI despite the poor frequency response.
http://www.hdtvprimer.com/ANTENNAS/comparing.html

Simulations show different radiation patterns, so one or the other might be
better for a particular situation. I have no idea how accurate the
simulations are.

Some people say that CM quality has gone downhill, and is now lower than
Winegard.

I picked the PR-8800 and it works well. PR-8800 works okay for VHF-HI.
I can't compare it with the 4228 since I don't have a 4228.

Have you ruled out the Yagis such as the XG91 and DAT75 ? I would
think that they would be preferred over the 8 bays for your situation?

I tried the 46XG and I my results were the same for Digital, but things got much worse for Analog. I have had the best Analog reception with the 4221, and if I end up staying with just analog for the next 20 months, the PR 8800 should be the best option.

But when testing REAL ANTENNAS (vice computer simulations cited above) the
CM-4228 demonstrated a consistent 2 dB improvement over W-G PR-8800 for CH20-68:
http://hdtv.forsandiego.com/messages/4364/3476.html?1126051755
http://www.avsforum.com/avs-vb/showthread.php?p=10555890&highlight=cozad#post10555890

PS: Kerry Cozad works for Dielectric, the guys who build DTV transmitter antennas.

Based on the bellow info for my area what outdoor antenna would work best for me?
From what i undersrtand it should be bi-directional. Othe then that is their a real adavantage to having amplifoed vs non-amplefied antenna and if anyone can recommend one it would be much appreciated.



DTV Antenna Call Sign Channel Network Compass Miles
Type Orientation From
* yellow - uhf KKPX-DT 65.1 ION 297° 37.8
* yellow - uhf KBCW-DT 44.1 CW 301° 41.8
* yellow - uhf KCNS-DT 38.1 SAH 301° 41.8
* yellow - uhf KGO-DT 7.1 ABC 301° 41.8
* yellow - uhf KBWB-DT 20.1 IND 301° 41.8
* yellow - uhf KPIX-DT 5.1 CBS 301° 41.8
* yellow - uhf KTSF-DT 26.1 IND 297° 37.8
* yellow - uhf KTVU-DT 2.1 FOX 301° 41.8
* yellow - uhf KFSF-DT 66.1 TFA 301° 41.8
* yellow - uhf KQED-DT 9.1 PBS 301° 41.8
* yellow - uhf KMTP-DT 33.1 IND 301° 41.8
* yellow - uhf KRON-DT 4.1 MNT 301° 41.8
* yellow - vhf KNTV-DT 11.1 NBC 297° 37.7
* yellow - uhf KCSM-DT 43.1 PBS 301° 41.8
* yellow - uhf KDTV-DT 14.1 UNI 358° 12.7
* yellow - uhf KSTS-DT 48.1 TEL 358° 12.7
* yellow - uhf KTEH-DT 54.1 PBS 0° 12
* yellow - uhf KICU-DT 36.1 IND 0° 12
* red - uhf KSMS-DT 31.1 UNI 139° 20.7
* blue - uhf KTLN-DT 47.1 IND 313° 68
* violet - vhf KSBW-DT 8.1 NBC 134° 45.4

> I've decided to find out if my situation will be improved by more
> antenna gain, so I need to decide between 2 models, the Wingard
> PR 8800 or the CM 4228.

> So, is there THAT much of a difference between the two?

A year ago I was deciding between these two. I waded through this entire
thread. Summary:

CM 4228 is steel and weighs more than the mostly aluminum Winegard PR-8800.

CM 4228 has higher wind load than PR-8800. Consumer TV rotors have problems
with the CM 4228. If you want to use the CM 4228 with a rotor look into
a heavy duty ham rotor.

PR-8800 has more gain than CM 4228 below channel 24-28.
CM 4228 has more gain than PR-8800 above channel 24-28.
CM 4228 is said to be usable for VHF-HI despite the poor frequency response.
http://www.hdtvprimer.com/ANTENNAS/comparing.html

Simulations show different radiation patterns, so one or the other might be
better for a particular situation. I have no idea how accurate the
simulations are.

Some people say that CM quality has gone downhill, and is now lower than
Winegard.

I picked the PR-8800 and it works well. PR-8800 works okay for VHF-HI.
I can't compare it with the 4228 since I don't have a 4228.

Have you ruled out the Yagis such as the XG91 and DAT75 ? I would
think that they would be preferred over the 8 bays for your situation?

Well, I bought and installed the PR 8800 in my attic. Same results. Analog signal on 43 pretty good, digital on 47, not there. As predicted by most, I was able to pick up some stations from the side, 4 in total.

I suppose next, I'll wait to install that Jointenna to see if that helps, after that, who knows. I may give up, or if I can't lose the itch, I'll try the stagger stacking method.

BTW, the Winegard construction was HORRID. All of the pieces were bent. It has dipoles that you have to unfold over plastic clips. Well, 90 percent were bent down, so that the only way to pull them over the clips was to bend them back. In doing this, I snapped 2 of the clips and hand to krazy glue them. I don't think that will hold if I move this thing to the mast and the outdoors. Very dissapointing.

FTR, I put up a CM 4228 with a CM 7777 and I have so far been fairly impressed. I'm in TV reception hell, and I get four very solid DTs (three are 38 mi, one is 63 mi away), three pretty good (two are 63 mi, and one is 85 mi) and four others that show up under ideal conditions.

I have no trouble picking up VHF as low as channel 8.

I am surrounded by a lot of opposing, taller hills, trees and most of my channels' directions overshoot the town and there is an FM tower a little over one mi away. I don't have a 5th gen tuner, either.

YMMV, but I'm happy with the CM 4228. The only other antenna that intrigues me is the XG-91.

Based on the bellow info for my area what outdoor antenna would work best for me?
From what i undersrtand it should be bi-directional. Othe then that is their a real adavantage to having amplifoed vs non-amplefied antenna and if anyone can recommend one it would be much appreciated.

Somehow the REAL channel numbers (on the far right) didn't get posted,
so fol. is "close" (give or take 0.1 mile)--a couple miles S. of San Jose Airport:

DTV, Antenna Type, Call Sign, "Fake" Channel, Network, City, State, Live Date,
Compass, Miles, "Real" Channel Assignment
* yellow - uhf KKPX-DT 65.1 ION SAN JOSE CA 298° 37.8 41
* yellow - uhf KBCW-DT 44.1 CW SAN FRANCISCO CA 301° 41.7 45
* yellow - uhf KCNS-DT 38.1 SAH SAN FRANCISCO CA 301° 41.7 39
* yellow - uhf KGO-DT 7.1 ABC SAN FRANCISCO CA 301° 41.7 24
* yellow - uhf KBWB-DT 20.1 IND SAN FRANCISCO CA 301° 41.8 19
* yellow - uhf KPIX-DT 5.1 CBS SAN FRANCISCO CA 301° 41.8 29
* yellow - uhf KTSF-DT 26.1 IND SAN FRANCISCO CA 298° 37.8 27
* yellow - uhf KTVU-DT 2.1 FOX OAKLAND CA 301° 41.7 56
* yellow - uhf KFSF-DT 66.1 TFA VALLEJO CA 301° 41.7 34
* yellow - uhf KQED-DT 9.1 PBS SAN FRANCISCO CA 301° 41.7 30
* yellow - uhf KMTP-DT 33.1 IND SAN FRANCISCO CA 301° 41.7 33
* yellow - vhf KNTV-DT 11.1 NBC SAN JOSE CA 297° 37.7 12
* yellow - uhf KCSM-DT 43.1 PBS SAN MATEO CA 301° 41.7 43
* yellow - uhf KDTV-DT 14.1 UNI SAN FRANCISCO CA 358° 12.7 51
* yellow - uhf KSTS-DT 48.1 TEL SAN JOSE CA 358° 12.7 49
* yellow - uhf KTEH-DT 54.1 PBS SAN JOSE CA 0° 12.1 50
* yellow - uhf KRON-DT 4.1 MNT SAN FRANCISCO CA 301° 41.7 57
* yellow - uhf KICU-DT 36.1 IND SAN JOSE CA 0° 12.1 52
* red - uhf KSMS-DT 31.1 UNI MONTEREY CA 139° 20.7 31
* blue - uhf KTLN-DT 47.1 IND NOVATO CA 313° 68.0 47

Note that VHF CH12 is NBC-HD....and by Feb2009 several other stations
will revert to VHF....so a combo VHF/UHF is best....

All "yellow" stations are all within a few degrees of same heading.
Since other stations are dupes, why would you want the "red" and "blue" stations?
if you do, you'll need to add a rotator....and probably a higher gain UHF antenna.

Any of the mid-range VHF/UHF combo antennas at Fry's (Lowes, R-S, etc)
should be adequate, such as CM-4016 or CM-4018 Advantage models:
http://www.starkelectronic.com/cmadv.htm

Preamp should not be needed....nearby stations are fairly close
and would preclude all except W-G HDP-269.

> I tried the 46XG

Is this the correct model number? Google couldn't find it.
There is a 42XG and a 43XG.
http://www.antennasdirect.com/42XG_television_antenna.html
http://www.antennasdirect.com/43XG_digital_antenna.html

Yeah it was 'fun' getting the elements into place. I managed to
do it without breaking anything. I guess none of the consumer
units are built the way we'd like them to be. Maybe the
commercial stuff like Blonder Tongue is better? At 10x the
price it ought to be.

While you have the PR-8800 in the attic, you could try improving
the reflector by adding some sheet aluminum. Sold for roof
flashing at hardware stores, Lowes, Home Depot, ...
This would catch a lot of wind outdoors, but not a problem in
the attic.

> I tried the 46XG

Is this the correct model number? Google couldn't find it.
There is a 42XG and a 43XG.
http://www.antennasdirect.com/42XG_television_antenna.html
http://www.antennasdirect.com/43XG_digital_antenna.html

Yeah it was 'fun' getting the elements into place. I managed to
do it without breaking anything. I guess none of the consumer
units are built the way we'd like them to be. Maybe the
commercial stuff like Blonder Tongue is better? At 10x the
price it ought to be.

While you have the PR-8800 in the attic, you could try improving
the reflector by adding some sheet aluminum. Sold for roof
flashing at hardware stores, Lowes, Home Depot, ...
This would catch a lot of wind outdoors, but not a problem in
the attic.

It was the 43XG

Somehow the REAL channel numbers (on the far right) didn't get posted,
so fol. is "close" (give or take 0.1 mile)--a couple miles S. of San Jose Airport:

DTV, Antenna Type, Call Sign, "Fake" Channel, Network, City, State, Live Date,
Compass, Miles, "Real" Channel Assignment
* yellow - uhf KKPX-DT 65.1 ION SAN JOSE CA 298° 37.8 41
* yellow - uhf KBCW-DT 44.1 CW SAN FRANCISCO CA 301° 41.7 45
* yellow - uhf KCNS-DT 38.1 SAH SAN FRANCISCO CA 301° 41.7 39
* yellow - uhf KGO-DT 7.1 ABC SAN FRANCISCO CA 301° 41.7 24
* yellow - uhf KBWB-DT 20.1 IND SAN FRANCISCO CA 301° 41.8 19
* yellow - uhf KPIX-DT 5.1 CBS SAN FRANCISCO CA 301° 41.8 29
* yellow - uhf KTSF-DT 26.1 IND SAN FRANCISCO CA 298° 37.8 27
* yellow - uhf KTVU-DT 2.1 FOX OAKLAND CA 301° 41.7 56
* yellow - uhf KFSF-DT 66.1 TFA VALLEJO CA 301° 41.7 34
* yellow - uhf KQED-DT 9.1 PBS SAN FRANCISCO CA 301° 41.7 30
* yellow - uhf KMTP-DT 33.1 IND SAN FRANCISCO CA 301° 41.7 33
* yellow - vhf KNTV-DT 11.1 NBC SAN JOSE CA 297° 37.7 12
* yellow - uhf KCSM-DT 43.1 PBS SAN MATEO CA 301° 41.7 43
* yellow - uhf KDTV-DT 14.1 UNI SAN FRANCISCO CA 358° 12.7 51
* yellow - uhf KSTS-DT 48.1 TEL SAN JOSE CA 358° 12.7 49
* yellow - uhf KTEH-DT 54.1 PBS SAN JOSE CA 0° 12.1 50
* yellow - uhf KRON-DT 4.1 MNT SAN FRANCISCO CA 301° 41.7 57
* yellow - uhf KICU-DT 36.1 IND SAN JOSE CA 0° 12.1 52
* red - uhf KSMS-DT 31.1 UNI MONTEREY CA 139° 20.7 31
* blue - uhf KTLN-DT 47.1 IND NOVATO CA 313° 68.0 47

Note that VHF CH12 is NBC-HD....and by Feb2009 several other stations
will revert to VHF....so a combo VHF/UHF is best....

All "yellow" stations are all within a few degrees of same heading.
Since other stations are dupes, why would you want the "red" and "blue" stations?
if you do, you'll need to add a rotator....and probably a higher gain UHF antenna.

Any of the mid-range VHF/UHF combo antennas at Fry's (Lowes, R-S, etc)
should be adequate, such as CM-4016 or CM-4018 Advantage models:
http://www.starkelectronic.com/cmadv.htm

Preamp should not be needed....nearby stations are fairly close
and would preclude all except W-G HDP-269.
Try the CODE switch, using brackets around CODE and /CODE.


* yellow - uhf KKPX-DT 65.1 ION SAN JOSE CA 298° 37.8 41
* yellow - uhf KBCW-DT 44.1 CW SAN FRANCISCO CA 301° 41.8 45
* yellow - uhf KCNS-DT 38.1 SAH SAN FRANCISCO CA 301° 41.7 39
* yellow - uhf KGO-DT 7.1 ABC SAN FRANCISCO CA 301° 41.7 24
* yellow - uhf KBWB-DT 20.1 IND SAN FRANCISCO CA 301° 41.8 19
* yellow - uhf KPIX-DT 5.1 CBS SAN FRANCISCO CA 301° 41.8 29
* yellow - uhf KTSF-DT 26.1 IND SAN FRANCISCO CA 298° 37.8 27
* yellow - uhf KTVU-DT 2.1 FOX OAKLAND CA 301° 41.7 56
* yellow - uhf KFSF-DT 66.1 TFA VALLEJO CA 301° 41.7 34
* yellow - uhf KQED-DT 9.1 PBS SAN FRANCISCO CA 301° 41.7 30
* yellow - uhf KMTP-DT 33.1 IND SAN FRANCISCO CA 301° 41.8 33
* yellow - vhf KNTV-DT 11.1 NBC SAN JOSE CA 297° 37.7 12
* yellow - uhf KCSM-DT 43.1 PBS SAN MATEO CA 301° 41.8 43
* yellow - uhf KDTV-DT 14.1 UNI SAN FRANCISCO CA 358° 12.7 51
* yellow - uhf KSTS-DT 48.1 TEL SAN JOSE CA 358° 12.7 49
* yellow - uhf KTEH-DT 54.1 PBS SAN JOSE CA 0° 12.1 50
* yellow - uhf KICU-DT 36.1 IND SAN JOSE CA 0° 12.1 52
* yellow - uhf KRON-DT 4.1 MNT SAN FRANCISCO CA 301° 41.7 57
* red - uhf KSMS-DT 31.1 UNI MONTEREY CA 139° 20.7 31
* blue - uhf KTLN-DT 47.1 IND NOVATO CA 313° 68.0 47

Note that VHF CH12 is NBC-HD....and by Feb2009 several other stations
will revert to VHF....so a combo VHF/UHF is best....

All "yellow" stations are all within a few degrees of same heading.
Since other stations are dupes, why would you want the "red" and "blue" stations?
if you do, you'll need to add a rotator....and probably a higher gain UHF antenna.

Any of the mid-range VHF/UHF combo antennas at Fry's (Lowes, R-S, etc)
should be adequate, such as CM-4016 or CM-4018 Advantage models:
http://www.starkelectronic.com/cmadv.htm

Preamp should not be needed....nearby stations are fairly close
and would preclude all except W-G HDP-269.

Just yellow stations is all i am interested in and since they're all in pretty much the same direction i should be able to pick them up with almost any antenna acc to my understanding.
so would somethign like this work? http://www.solidsignal.com/prod_display.asp?prod=ANWGS1100
I am trying to stay away from the big bulky antenna for asthetic and ease of install reasons.

At 40 miles, you're a bit far out for that antenna....and it doesn't provide much suppression
of multipath coming from surrounding mountains.

If you're looking for a somewhat lower profile antenna, would the CM4228 fit the WAF???
It's one of the best UHF antennas, with moderate hi-VHF (CH7-13) performance.

Any of the 4-Bay antennas (CM-4221, W-G PR4400, AD DB-4) would work for UHF,
but may come up short for VHF stations....but is still worth trying.

A few posts up, I mentioned how I purchased a new Winegard PR8800 Antenna, and it was damaged out of the box.

I relayed my story to the Customer Service email address on Winegard's website, and they told me they'd send me another one!

They just earned a customer for life!

They just earned a customer for life!


Before you commit to that, wait until you see what arrives :p

Just kidding. But please DO let us know about it. I'm on the fence about buying an 8800. The low UHF reception it's supposed to have is intriguing.

Before you commit to that, wait until you see what arrives :p

Just kidding. But please DO let us know about it. I'm on the fence about buying an 8800. The low UHF reception it's supposed to have is intriguing.
wasn't toby ziegler the presidents right hand man on west wing?

Before you commit to that, wait until you see what arrives :p

Just kidding. But please DO let us know about it. I'm on the fence about buying an 8800. The low UHF reception it's supposed to have is intriguing.


The 8800 appears to be great a pulling in Digital signals, especially from a wide angle. I'm pulling in FOX while the antenna is pointed 175 degrees away from the towers. It's not really doing what I hoped it would, but I have a bit of a unique situation, with an overly strong signal, and I really didn't expect it to.

I probably need to stagger stack. One of the reasons I wanted the 8800 is that I can take them apart and use them as 2 separate 4 bays and stagger them.

As I said, you can't beat the customer service.

wasn't toby ziegler the presidents right hand man on west wing?

Yeppers.....picked the name after him......love grumpy curmudgeons.

Having learned there are three low powered digital repeaters on the air in the area where I live, I purchased a Channel Master 4228 and a CM 0064 amplifier. Being an old time DXer, I did it more for the challenge than for the viewing because I already have two HD satellite systems.

The antenna arrived yesterday afternoon and not having time till this weekend to do a permanent roof install, I did a temporary hookup propping it against a patio chair about two feet above the ground and behind a concrete wall. To my surprise after doing a channel scan with the ATSC tuner in my SONY 50" I logged 27 channels with a high number of duplicated programs due to the number of repeaters scattered throughout this area. All of the digital signals were flawless.

I then decided to hook up the setup to my DISH 942 DVR. After autoscanning I only picked up 13 channels but all of the digitals came in at 100% signal strength and with the bonus of having the channels integrated in the program guide with the ability to DVR them.

This morning I decided to swing the antenna around about a 130 degrees to look at another hill about 12 miles away with a set of low power repeaters. After doing so I went inside and found a Lost Signal message on the screen. I assumed I might have shorted the 300 ohm connection at the antenna or have a wiring problem. After checking it out thoroughly I still had the problem. After going through some basic swap and reboot procedures I decided to hook the antenna back up to the SONY and lo and behold everything is fine. Returning it back to the DISH 942, the Lost Signal message returns. At this point I'm thinking I had a random, coincidental failure of the tuner in the 942.

Anyone have a clue or thought????

Perhaps the difference is because Dish 942 doesn't receive analog stations.

Per www.TVFool.com list of station locations (downloaded into Google Earth),
there are five DTV directions from St. George, UT:

1 mile N-W: 1 analog
1 mile S: 1 analog
3 miles S: 10 analog and 3 digital
3 miles S-E: 4 analog
17 miles W: 11 analog and 3 digital
25 miles E: 17 analog and 4 digital
31 miles N: 4 analog and 1 digital
34-48 miles N-E: 8 analog and 7 digital

They're everywhere!!!! They're everywhere!!!!

So that's about 56 analog and 18 digitals near St. George, plus whatever
might be possible further away....minus whatever isn't on the air yet...

And with so many occupied channels, there may be problems with
a particular channel making it difficult to receive adjacent and
next adjacent channel assignments....which depends on quality of tuner....

You should enter your location into www.antennaweb.org and www.tvfool.com
in order to see what is possible and in what direction.

How old are the TV and the DVR? If the TV is newer, it's possible that it has a better tuner (more sensitive and/or less prone to multipath interference, etc.).

Before you commit to that, wait until you see what arrives :p

Just kidding. But please DO let us know about it. I'm on the fence about buying an 8800. The low UHF reception it's supposed to have is intriguing.
Just in case one person's story might help, our Fox station is on physical channel 15 and very tough to receive -- it's about 20 miles away and very low powered (still :(). My PR-4400 wouldn't get it, so I got a PR-8800. This worked well, but only when the antenna was perfectly positioned. Hoping for more improvement, I got a CM 4228. The 4228 was worse; it barely got a signal at all. I compared the two over a period of several days, but the situation didn't change -- the 8800 was better every time. I ended up returning the 4228.

So for me, the Winegard definitely worked better on the lower channels, just as the HDTV Primer graphs show.

Oh, and also for the record, this was for an apartment patio, so I wasn't able to use a long yagi. But I've always wondered if the 9032 or other Winegard yagi would be even better, as the Winegard figures show. I've never understood why the Winegard gain figures are much better for their best yagi over their 8-bay, while CM has the 4228 as better than their best yagi.

Anyway, back to the 8800. Years later I got a CM 4228 when my Winegard became very beat up after numerous falls -- that's a downside to the lighter weight aluminum -- and I have to say that in analog testing of fringe UHF stations, I can't tell that the 4228 receives any better even on the mid UHF channels. If there's a difference, I'd bet it was because of the 4228's screen.

Here's something -- I've considered getting some good #10 copper wire and extending the length of the 4228's elements slightly to see how much that would improve the 4228 on the lower channels. Has anyone ever tried a modification like that?

At 40 miles, you're a bit far out for that antenna....and it doesn't provide much suppression
of multipath coming from surrounding mountains.

If you're looking for a somewhat lower profile antenna, would the CM4228 fit the WAF???
It's one of the best UHF antennas, with moderate hi-VHF (CH7-13) performance.

Any of the 4-Bay antennas (CM-4221, W-G PR4400, AD DB-4) would work for UHF,
but may come up short for VHF stations....but is still worth trying.

okay, bought a CM-4221 today at Fry's - BTW its on sale there for $29
will try it out and let you know.

Here's something -- I've considered getting some good #10 copper wire and extending the length of the 4228's elements slightly to see how much that would improve the 4228 on the lower channels. Has anyone ever tried a modification like that?

I've wondered the same thing. A while back (maybe a different thread...who can keep track?) I asked about optimizing UHF antennas. UHF used to span from channel 14 up to 83 (or 82, 84, somewhere up there). In the early 1980's UHF was trimmed back to channel 69 on the high end. Now it's about to be trimmed back to channel 51 for the most part. Has anyone redesigned the antennas for the narrower band, so that a bit more performance could be achieved? I've never heard anything definite about it.

But lengthening the elements would seem to be a step in that direction. Moving the screen a bit farther from the elements would seem to be in order too, but that would be more work. If I recall things I've read, the bowtie angle could be narrowed too. A straight dipole is best for a single frequency. A wider angle is better for a band of frequencies. So something inbetween the stock angle and a straight dipole would seem to be better for a narrower band of frequencies.

The antennas are built for outside installation. But if you're playing with one in an attic, you have more options, because you don't have to worry about icing or wind. Perhaps the screen can be improved by covering it with metal window screen or aluminum foil. Every dB helps, whether it's in gain, beam width, front to back ratio, whatever. Perhaps the screen could be widened too. And hey, one of the great things about playing with antennas is that you can experiment for minimal cost, with little risk of damage to equipment, and if something performs worse, you can put it back to how it was before you started. Just be careful about electrical safety, don't fall off a ladder/tower, and don't put your foot through your bedroom's drywall ceiling.

okay, bought a CM-4221 today at Fry's - BTW its on sale there for $29
will try it out and let you know.

wow... this thing rocks! I get all the HD stations clear - no artifacts. Huge improvement over the hyped up indoor Phillips I was using.. and it was just sitting on the floor in front of the tv.

Now i need to find where to mount it. Whats a good place to find a mounting kit for roof antenna?

wow... this thing rocks! I get all the HD stations clear - no artifacts. Huge improvement over the hyped up indoor Phillips I was using.. and it was just sitting on the floor in front of the tv.

Now i need to find where to mount it. Whats a good place to find a mounting kit for roof antenna?

Radio Shack is good for mounting supplies. They are also good because, so long as you don't screw the item up too badly, you can return it.

I have a 10 foot mast, attached to another 5 foot, mounted to my chimney with a wall mount. I got it all from Radio Shack. Oh, and this was all for my CM 4221.