The Official AVS Antenna Topic! [Text View] - Page 39

hphase

06-20-09, 05:09 PM

Many stations are upgrading to circular polarization (both Horiz & Vertical) which
means 45-degree antenna has a chance of receiving one, the other or both.
FCC allows stations to DOUBLE their total power if circular polarization....it's
effectively two separate antennas driven by two separate transmitters.....
EACH at the authorized ERP level if it were strictly horizontally polarized
[and I'm sure someone will point out exceptions to this general "rule"...]

Stations can add a vertically-polarized component to their signal as long as the ERP in the vertical polarization does not exceed the licensed ERP in the horizontal polarization. This allows better reception by another linearly polarized antenna with a random orienation (vertical, horizontal, or anything in between.) Adding an equal vertical component requires a doubling of transmitter power, and also doubles the power bill, too.

But, for true circular polarization, there has to be a 90 degree phase shift applied to the vertical component. Circular polarization was originally introduced into analog TV broadcasting to help reduce ghosts. This is because the sense of circular polarization (left- or right-hand) is reversed when the signal reflects off of a building or other obstruction. A circularly polarized antenna will not pick up the refected signal because its polarization is opposite to what it was designed to receive.

When stations add a vertical component to their horizontal component, but don't add the phase shift, that would probably be called "dual polarization," not circular. If the vertical component isn't equal to the horizontal, that would be called elliptical polarization.

nordloewelabs

06-20-09, 05:49 PM

wrong info. disregard this post.

kinemax

06-20-09, 05:58 PM

So, I bought an Antennas Direct DB4 antenna a while back, threw it up in the attic attached to a piece of pvc pipe and aligned it using the signal bars on my tv. Quick......Done. I was getting 8 - 10 bars out of 10 on all UHF digital channels so I was really happy. That combined with NetFlix via a Roku box and goodbye cable. Then the DTV June 12th transition occurred and three channels moved to the upper VHF band (RF channels 7, 11 and 13)... I now get these channels intermittently. So, I am thinking of either adding a small cheap upper VHF antenna (AntennaCraft Y5-7-13 seems highly recommended) or just throwing out the DB4 and putting up something like a Winegard HD7694P. What is the better choice, and is either one acceptable, considering that I want to keep it in the attic for various reasons, and I am trying not to get something that is overkill...
I am in Central NJ (about 35 miles from NYC) and in the same boat: I can't get 13, while 7 & 11 come and go. I tried the DB4-widening (with rod-extension) method suggested by arbie without success. Is augmentation with a Y5-7-13 sufficient or do I need something better like a Y10-7-13 or a YA-1713? Or should I just go for a HD769x and if so which one?

TIA.

EscapeVelocity

06-20-09, 09:47 PM

Here is an interesting antenna...

Terk TV-35

http://ecx.images-amazon.com/images/I/310-A4uB10L._SS500_.jpg

• Due to the compact and durable design, the TERK TV35 will outlast most traditional yagi antennas. No tools required, the TV35 includes everything needed to make it an easy to install antenna.
• Dimensions: 76 7/8” W x 38 1/32” L
• Weight: 2.65lbs.
• Element Type: 10 Elements
• Operational Bandwidth: 54-806MHz
• Gain VHF: 0-4dB
• Gain UHF: 2.5-8.5dB
• Front-to-Back Ratio: 12dB (VHF), 15dB (UHF

http://www.hometheatermag.com/images/archivesart/303ant.4.jpg

pjc123

06-20-09, 10:21 PM

I am in Central NJ (about 35 miles from NYC) and in the same boat: I can't get 13, while 7 & 11 come and go. I tried the DB4-widening (with rod-extension) method suggested by arbie without success. Is augmentation with a Y5-7-13 sufficient or do I need something better like a Y10-7-13 or a YA-1713? Or should I just go for a HD769x and if so which one?

TIA.

Thanks for trying the rod extension by the way, since I just don't have the time to fool with it. As a side note, I emailed the following to Winegard with their response attatched:

I need some pre-sales technical help.

I currently have an Antennas Direct DB4 antenna in my attic that works very well (9 to 10 bars out of 10 using my TV’s signal meter on all UHF channels). However, New York City just switched 3 stations to the High VHF band after the June 12th transition, so now these stations intermittently come in. So I could just get a VHF only antenna and combine them, but probably just write it off as a loss and just buy a new single VHF/UHF antenna.

Here is my situation:
I need color code yellow and red.
I have 3 High VHF stations (7, 11, and 13)
The rest of the stations are UHF
The mileage is 22 for all the stations.
There are 6 degrees between all broadcasting towers.
MOST IMPORTANTLY I will be installing this in an attic because it is only temporary (I will eventually be moving), so I want to insure I have enough gain to compensate for any loss. The roof material is regular asphalt shingles and I am in a residential area with all ranch style homes and no tall buildings, just a few trees.

I was looking at the HD7694P, but will it compensate for the attic and should I "kick it up a notch"? Also, if I went with a separate VHF antenna instead, what would you recommend? What is the recommend combiner as well?

Thanks

This was the response:

I would suggest the HD7696P antenna to be sure we have enough signal. If you wish to add a VHF antenna then the model YA-1713 would your antenna choice. You will need to find a UHF/ VHF combiner to combine the VHF antenna and UHF antenna with minimum amount of loss.

I also emailed Antennacraft about their Y5-7-13, but never received a response. I like the Antennacraft because it is a reasonable size like the DB4. However, I am reading bad things about Antennacrafts quality from various forums, but in an attic I could care less about wear and tear from the elements.

I am still waiting to hear from someone who has used a specific brand and model with good results, especially in the Central NJ area, before I buy yet another antenna that does not work. I will post anything that I find out.

EscapeVelocity

06-21-09, 12:01 AM

Wade UHF Parabolic antennas pdf (http://www.wade-antenna.com/Wade/uhfparabolic.pdf)

Wade Helical (Helix) UHF Antenna pdf (http://www.tacocommunications.com/Wade/WH14-69.pdf)

systems2000

06-21-09, 12:38 AM

Since I get huge amounts of Co-Channel, Adjacent Channel, & Multi-Path interference, I've been thinking of the garbage can solution, but I think the screen solution would be more elegent.

Does anyone know if that would eliminate the problem of using dissimilar antennas causing interference with each other when using a combiner? I'd like to tie several single channel yagi's together (ie. 47 @ 87°, 8 @ 218°, & 32 @ 322° (maybe more)).

I've also been thinking about experimenting with a Primestar dish and retro-fitting it for terrestrial DTV reception. I believe the dish is made of carbon resin and should make for a fine reflector. :)

On another note, what's the beamwidth of the YA-1713?

finlay648

06-21-09, 01:15 AM

I'd look at the weakest station that you want to receive. Next, using tvfool, try swapping the two antennas. I'd install the antennas in whichever position gave you the most margin on the weakest station.

I have beenusing 2 CM4228s stacked vertically as my antenna pre-transition but post-transition 9, 11 and 13 went to HI-VHF and I lost reception of 9 and 11. I purchased a YA-1713 to boost reception for 9 and 11. I tried mounting the YA-1713 below the CM4228s (relatively easy to do) but the results were marginally better (9 was better but 11 was about the same). I then lowered the 4228s by a foot and installed the 1713 at the top of the mast with much improved results.

I suppose this means that there is horizontal banding from diffraction and the first location was in a null while the second location was not. I didn't notice any change in the reception of the UHF channels but this makes me wonder if the UHF antennas may be partially in a null. I'm assuming that the size of the bands and their location vary with frequency. Given that the stacked 4228s are about 6' tall, is it likely that there are multiple higher frequency bands spanning the 4228s or am I completely misunderstanding how this works?

I'm thinking that I probably have to redo this setup since seasonal changes will negatively impact it and I'm wondering what are the factors that impact reception the most.

My tvfool info is:

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d618ac2e3f7e60d

BTW while looking at the tvfool results for different antnna heights I noticed that reception seemed to get poorer as the height increased above 20' (e.g. to 30' or 40'). That seems counter to what I expected.

ProjectSHO89

06-21-09, 08:24 AM

This was the response:

I would suggest the HD7696P antenna to be sure we have enough signal. If you wish to add a VHF antenna then the model YA-1713 would your antenna choice. You will need to find a UHF/ VHF combiner to combine the VHF antenna and UHF antenna with minimum amount of loss.

Anyone find it ironic that Winegard's tech support suggested adding a big HVHF antenna to one of their own antennas that ALREADY HAS HVHF??? Especially one that has almost as much HVHF gain as doe the YA1713...

The 7694 should do fine. Worst case, go to the 7695.

arxaw

06-21-09, 09:03 AM

...I then lowered the 4228s by a foot and installed the 1713 at the top of the mast with much improved results.

I suppose this means that there is horizontal banding from diffraction and the first location was in a null while the second location was not.....I'm assuming that the size of the bands and their location vary with frequency. Correct, the bands vary by frequency. VHF may require moving the antenna farther than UHF to find a hot spot.

Interesting article on fringe reception (http://www.hdtvexpert.com/pages_c/DTVtransitionRevisited.html).

PA_MainyYak

06-21-09, 10:33 AM

I need recs for this situation. Friend of mines, place in the mountains of North Carolina, near Mt. Mitchell.

Old Mill house is metal sheathed.

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d7f1480d77d8eb6

Please help!

You might try fine tuning your TV Fool results by using GPS coordinates (easily obtainable thought Google Earth or similar mapping programs). And as mentioned elsewhere, finding a way to raise the antenna higher. At that, reception at the cabin will remain a significant challenge.

kinemax

06-21-09, 10:38 AM

Thanks for trying the rod extension by the way, since I just don't have the time to fool with it.
...

I am not sure I have done the rod-extension method justice, as I have only tried using coat-hanger wires as the extended rods. It seemed to yield a slight increase in signal strength but not enough to form a proper video image, so perhaps some better rod materials might make a critical difference.

I am still waiting to hear from someone who has used a specific brand and model with good results, especially in the Central NJ area, before I buy yet another antenna that does not work. I will post anything that I find out.
I just realized that both the 7-13 and 7-69 antenna types would leave out the FM band which I also need, hence I am now looking at the HD708x series (most likely the 7080 since the 7082 or 7084 are probably too big to get in my attic). I also found out that Radio Shack has a VU-90XR for about $65; I am tempted to try it since their VU-110XR which I bought over 15 years ago is doing a wonderful job pulling in all three stations for my other TV on the first floor.

arxaw

06-21-09, 11:00 AM

...their VU-110XR which I bought over 15 years ago is doing a wonderful job pulling in all three stations for my other TV on the first floor.Would it be possible to just split the feed from that antenna to the other TV?

nordloewelabs

06-21-09, 11:52 AM

As of me, I received my CM-3030 today with the CM-3038 preamp. Have to check out how it works at 33 miles from NYC.

let us know your impressions after you try them.

rbarbier

06-21-09, 12:28 PM

A heads up regarding the UVSJ (diplexer) that is included with the C5:

The plastic case will accommodate either a compression- or crimp-fit F-connector but will not allow the lid to close if you're using a cable with a longer-length factory molded connector or an RG11 compression fitting.

Plan accordingly.

About two weeks ago I was able to get my hands one of the first pre-production C5 antennas.

With an antenna height of only about 12 feet and a good test location (empty lot at NEQ of I-44 at Gray Summit, MO at around 8 AM), I was able to see a near-perfect 8VSB waveform on my Sencore 1474 of KRCG-13 (VHF-12 out of Jefferson City) of more than adequate amplitude to be useful. Distance of about 70 miles with little intervening noise generators. Measured value was approximately -30 dBmV with a C/N ratio of 9.5. Very easily usable with a decent low noise preamp or with some more height.

FCC-predicted signal level was -94 dBm, TV fool for the same spot was -98.1 dBm.

I will be feeding the C4 and the C5 into my Channelmaster 7777. Do you think this is a good idea instead of the included uhf/vhf combiner? So after your test, do you think I will have good luck for 7, 9, 11 and 13 at my area?

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d618a760b64bf73

I get great UHF with the C4 right now in my area and the VHF are the same distance and degrees.

300ohm

06-21-09, 07:13 PM

What does it look like today?

WPVI may have rasied power last night.
Yeah, it was on their 6 oclock news tonight. They raised it from 7.56 KW to 30.2 KW, 400% the power of 6/13/09 and about 40% of their old analog power. My signal meter still jumps more on channel 6 than on any other channel, going from 90-95% to 50-60% and then quickly back up again. (the rest of the channels may jump 10-15% max) Not sure whats up with that, but at least the signal is at a higher level and the picture doesnt cut in/out. Keep in mind, I have a fairly high gain vhf antenna that a lot in this area dont.

I also checked out 87.7 FM in the car, where I used to pick up the WPVI-TV channel 6 audio. Its very quiet, exactly like any other no station area. As far as I can tell, FM reception on the lower end of the dial hasnt gotten any better or worse since 6/12/09. If they were to go back up to their old analog level of 74.1 KW with digital, I cant see where that would be any worse for the FM stations.

ProjectSHO89

06-21-09, 08:18 PM

I will be feeding the C4 and the C5 into my Channelmaster 7777. Do you think this is a good idea instead of the included uhf/vhf combiner? So after your test, do you think I will have good luck for 7, 9, 11 and 13 at my area?

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d618a760b64bf73

I get great UHF with the C4 right now in my area and the VHF are the same distance and degrees.

Using the separate inputs of your 7777 is the best way to go. Don't forget to flip the necessary switch.

Those TVfool numbers are much better (about 20 dB) than where I tested a couple of weeks ago. I'd expect pretty good results.

hphase

06-21-09, 08:35 PM

If they were to go back up to their old analog level of 74.1 KW with digital, I cant see where that would be any worse for the FM stations.
You have to understand how the digital spectrum is different from the analog spectrum. The digital signal fills the channel wall-to-wall, but analog has distinct peaks. One at the visual carrier, another smaller one at the chroma subcarrier, and another at the aural carrier. Of these, the closest to the FM band is the aural carrier. The rest of the channel is pretty empty.

There is no way they could put 74 kW digital through their existing analog transmission plant, so that will never happen. The digital peaks would be way too high. I wonder how much they increased their digital power, if at all.

holl_ands

06-21-09, 09:14 PM

Frequently, power increases are accomplished by "simply" swapping in a
higher gain antenna, which means stacking more elements vertically to
narrow down the elevation pattern:
http://www.dielectric.com/broadcast/brochures/TF-batwing.pdf

Tower Guy

06-21-09, 09:30 PM

There is no way they could put 74 kW digital through their existing analog transmission plant, so that will never happen. I wonder how much they increased their digital power, if at all.

WPVI's average DTV power is now 30.2 KW. The peak to average ratio is just over 4, so the peak power is 120 KW+. The analog power was measured as 74 KW peak. The analog antenna may be able to handle even more digital power.

WPVI's antenna is a 6 bay. Yes, you can use more antenna gain, but the close-in viewers will actually get less signal. 6 antenna bays is about the best compromise.

rbarbier

06-21-09, 11:17 PM

Using the separate inputs of your 7777 is the best way to go. Don't forget to flip the necessary switch.

Those TVfool numbers are much better (about 20 dB) than where I tested a couple of weeks ago. I'd expect pretty good results.

Thanks! I did switch the switches in preparation for the C5. My antenna is on my balcony so it is very easy to get to. Thanks for all the help and info. You provide a great (and free) service for all of us!

systems2000

06-22-09, 12:29 AM

Correct, the bands vary by frequency. VHF may require moving the antenna farther than UHF to find a hot spot.

Interesting article on fringe reception (http://www.hdtvexpert.com/pages_c/DTVtransitionRevisited.html).
I've also noticed the same issue with VHF & UHF not being on the same heading for stations that are knife-edge reception. D.C. VHF comes in better on a heading that is North of the UHF heading. Since WJZ-DT is so strong for me, I can't confirm the same for Baltimore.

I especially like the last bit of information. It reinforces what I've been discovering about peoples attitude of good reception DTV. Bye, bye cbale and satellite.

300ohm

06-22-09, 01:12 AM

Since WJZ-DT is so strong for me, I can't confirm the same for Baltimore.
Hows WBAL channel 11 for you ?

WPVI's average DTV power is now 30.2 KW.
Yeah, the news footage showed the FCC guys measuring signal levels all over the place. I cant believe they didnt do that a year ago, heh. Ironically, they have an TV ad "6 ABC-HD, The First to Go High Definition in the Delaware Valley".

From the tidbits Ive gathered, it seems the FCC in the early days of TV in the 1940s, licensed stations initially with too much power and then eventually cut back. It seems to me, from a viewers stand point, thats a better strategy than starting with too little power and then adding on.

EscapeVelocity

06-22-09, 03:16 AM

1957

http://img.auctiva.com/imgdata/5/1/8/8/6/6/webimg/274212644_o.jpg

arxaw

06-22-09, 09:18 AM

I will be feeding the C4 and the C5 into my Channelmaster 7777. Do you think this is a good idea instead of the included uhf/vhf combiner? If you use the 7777, yes. Use the built-in V/U inputs option, instead of a separate V/U combiner. Open the 7777's case and flip the internal "combined-separate" input switch to "separate."

Yeah, it was on their 6 oclock news tonight. They raised it from 7.56 KW to 30.2 KW, 400% the power of 6/13/09 and about 40% of their old analog power. My signal meter still jumps more on channel 6 than on any other channel, going from 90-95% to 50-60% and then quickly back up again. (the rest of the channels may jump 10-15% max) Not sure whats up with thatFM interference (?). Do you have an FM trap on your TV antenna?

Don F.

06-22-09, 10:40 AM

RickGA

06-22-09, 11:03 AM

1957

http://img.auctiva.com/imgdata/5/1/8/8/6/6/webimg/274212644_o.jpg

WOW, that antenna in the foreground is the exact type we had on the roof of our house, when I was a kid in the 1960's!!

rbarbier

06-22-09, 11:08 AM

I have on order a ClearStream C4. I am trying to improve my vhf reception over my current cm 4228. My cm preamp only has a 300 ohm input. Is there a way around the C4's transformer, if I should want to use the preamp? Thanks for any help..

This probably won't answer your question but I bought the C4 a couple of months ago because I knew some of my channels were moving to the High VHF side. I thought this antenna would work but it doesn't. It is a great UHF antenna. That is why I went with the C5 because it is supposed to be equivalent to a 5 element Yagi. I am also 57 miles away. I heard if I was closer (like within 40 miles), it would probably work (the C4).

Don F.

06-22-09, 11:27 AM

Sorry to hear that. My targets are about 65 miles away, as are the uhf stations.
The 4228 has no problem with uhf, but vhf is a problem. Thanks for the info..

hphase

06-22-09, 12:24 PM

Ironically, they have an TV ad "6 ABC-HD, The First to Go High Definition in the Delaware Valley".
Yep, WPVI was on the air on November 1, 1998 on channel 64. You could even pick them up in New York City. They must have beaten KYW, which would have been their only competition in the DTV race.

WPVI's average DTV power is now 30.2 KW. The peak to average ratio is just over 4, so the peak power is 120 KW+. The analog power was measured as 74 KW peak. The analog antenna may be able to handle even more digital power.
Depending on how much the WPVI transmission plant was over-designed, you might already need some clipping in the transmitter. You wouldn't want arcing in the transmission line or antenna. The sneaky little problem with 8-VSB, even with a "little" clipping, is that clipping causes frequency "splatter" and also increases the error vector magnitude. This means that, unlike analog transmissions, peak limiting doesn't just make your signal look bad. It actually reduces the area that can sucessfully decode the signal. That translates directly to reduced coverage, something that the power increase was hoped to fix...

rbarbier

06-22-09, 12:40 PM

Sorry to hear that. My targets are about 65 miles away, as are the uhf stations.
The 4228 has no problem with uhf, but vhf is a problem. Thanks for the info..

I think you are going to have problems with the VHF at 65 miles away with the C4.

300ohm

06-22-09, 02:23 PM

FM interference (?). Do you have an FM trap on your TV antenna?
Yep, the FM trap on my CM0264 is "IN". I dont think its FM interference causing the large jumps in the signal meter. Ill have to get a stop watch and time the jump pattern. (there seems to be a pattern, but not quite an even pattern) Its a puzzler, but WPVI is still tweaking, so Ill wait until theyre all done.

arxaw

06-22-09, 02:30 PM

Low VHF is no place for DTV to be.

arbie

06-22-09, 02:42 PM

For extension with rods, what type of materials did you use or would suggest for use as the extended rods and for mounting them?

TIA.

I salvaged my rods (3/16" diameter aluminum) from an old CushCraft circularly polarized yagi. In another forum, http://www.avsforum.com/avs-vb/showpost.php?p=16692144&postcount=2709, 300ohm suggested green plastic covered garden stakes as a cheap source of metal rods. For attachment, I used U-bolts, although for experimenting, you could even use UV tie wraps. Bottomline: don't spend more than the cost of a new antenna...

holl_ands

06-22-09, 04:10 PM

On another note, what's the beamwidth of the YA-1713?
W-G specs for YA-1713:
http://www.winegard.com/kbase/upload/ya-1713.pdf
and other W-G antennas:
http://www.winegard.com/offair/antenna_list.php

NEC Sim results (such as they are) for YA-1713:
www.imageevent.com/holl_ands/wgya1713
I think Gain and F/B results are believable....SWR (& Net Gain) not so much....

hphase

06-22-09, 05:09 PM

Tower Guy

06-22-09, 07:06 PM

Yep, WPVI was on the air on November 1, 1998 on channel 64. You could even pick them up in New York City. They must have beaten KYW, which would have been their only competition in the DTV race.

Depending on how much the WPVI transmission plant was over-designed, you might already need some clipping in the transmitter. You wouldn't want arcing in the transmission line or antenna. The sneaky little problem with 8-VSB, even with a "little" clipping, is that clipping causes frequency "splatter" and also increases the error vector magnitude. This means that, unlike analog transmissions, peak limiting doesn't just make your signal look bad. It actually reduces the area that can sucessfully decode the signal. That translates directly to reduced coverage, something that the power increase was hoped to fix...

It seems that WPVI built a facility capable of 30 KW.

The WPVI digital transmitter is brand new. If it had too much peak clipping would cause a low signal to noise ratio and high EVM. That error would be obvious.

Arcing in the antenna would trip the SWR overload sensor.

ProjectSHO89

06-22-09, 07:46 PM

I think you are going to have problems with the VHF at 65 miles away with the C4.

That's an understatement.....

UHF at that distance with good signal path, yes.

Any VHF-high at 65 miles, probably not. Figure 40-45 miles best case.

VHF-LO, forget it.

ProjectSHO89

06-22-09, 07:48 PM

Low VHF is no place for DTV to be.

Unfortunately for the viewers so afflicted, they're stuck with it unless the viewers or advertisers can convince station management to get their head out of their backside.

neilkaz

06-22-09, 08:16 PM

Sorry to potentially hijack this thread, but all those plots made my head spin. I'm not too concerned about gain, but F/B ratio is very important for me, especially on channels 11 and 13.

What is a believable F/B number to expect for a YA-1713? I'm still tempted to build K6STI's 5-element Yagi, primarily for its F/B ratio. Should I build or buy?

Thanks!

Here's Winegard's specs and measured patterns. http://www.solidsignal.com/manuals/ya1713.pdf

This antenna has been around for at least 20 years(likely longer) as it is in catalogs that I used to have that were at least that old. I have never used this antenna so I cannot say what real life performance is.

I have Ken Nist's model loaded into EZNEC here, not yet being comfortable enough with 4nec2 to use it.

Modelled F/B is as follows from chan 11-13

198...21.4 dB with F/R being about 18.6 dB
201...36.3 dB with F/R being about 20 dB
204...19.2 dB with F/R same
207...12.4 db with F/R same
210...8.9 dB with F/R same
213...8.5 dB with F/R same
216...16 dB with F/R 11.8 dB

This seems to show that this is a considerably better antenna for 11 then 13, which is consistant with what I recall reading about it.

Re: the lousy modelled impedance for the YA-1713, especially at the very high end. My modelling shows the same thing, but at least for freqs closer to band center, one cannot believe that Winegard has been selling this antenna for decades with such poor SWR, although one can believe that performance suffers somewhat at band edge chan 13.

When I change the length of the short element 3 from 19.4" to 28", the antenna becomed quite a good match to 75 ohms (although it gets worse for chan 13). However, I assume the Winegards balun is doing something to compensate for the reactance causing mismatch in the model (assuming that the model is perfectly reflecting real life (I doubt it for impedance here).

Ken Nist has stated that adding directors helps. You could add directors by taking then from another 1713 (40 bucks each) or by simply adding the end section (gaining 3 more directors (although likely not optimally spaced)) from another 1713. I've done some modelling of this. Guys with the 4nec2 optimizer may be able to tell you how to easily improve F/B for 13 without messing up impedance very much.

If good F/B is a must, you may want to stagger stack two of them. Here's the basic idea http://www.anarc.org/wtfda/stagger.pdf

I did this with 2 Antennacraft FM13's (F/B was not that good on higher FM on a single factory model as observed by me then and also modelled by K6STI) and clearly improved F/B. This technique also improved F/B when I combined my two custom channel 12 Yagis (although they had good F/B to begin with).

If stagger stacking, I'd put the lower antenna ahead of the upper. This is less moment arm for the rotor. This also means that elevation beam will be steered a couple degrees towards the ground (no big deal) and more importantly a major side lobe goes up into the air rather than towards the ground where it might pick up ground bounce.

More importantly, and not realized by me a decade ago when I did much FM and TV antenna stuff here, I'd connect the two staggered antenna 180 degrees out of phase and then add 90 degrees phasing to the other one than shown in the model. This should create a much more broadbanded stagger stack.

Anyhow...enough rambling. I'd get the YA-1713 if I were you, and to the antenna guru's here, lets see if we can improve it somewhat.

EDIT: I'll correct myself that after further reading I've seen reports that the YA-1713 is fine on 13 in real life.

.. neilkaz ..

kinemax

06-22-09, 08:31 PM

Would it be possible to just split the feed from that antenna to the other TV?
My VU-110XR (located in the attic) currently has its signals amplified by a CM-7777 to drive 50+ ft of cable to the TV (on the first floor). Where should I insert the splitter: before or after the preamp?

arxaw

06-22-09, 09:10 PM

If using a standard splitter, put it on the "Out to TV" side of the 7777 preamp's power supply.

http://www.warrenelectronics.com/antennas/preampsetup.jpg

Falcon_77

06-22-09, 10:13 PM

Which antenna is better for 12 & 13:

YA-1713
Y10-7-13

I ended up getting another YA-1713, but I just remembered that there was another antenna that was once available, though not through retail outlets, the Funke PSP 1922:

http://www.funke.nl/library/1190_098502_psp1922_051203_790500985.pdf

I remember that MAX HD/Midwest Dxer had these, but that the last one sold a while ago.

With so many having problems with upper VHF, it would be nice to have these available again. Though, granted, many having problems are trying to use rabbit ears.

Still, I'm not sure I could manage a 13' antenna in the attic. ;)

EscapeVelocity

06-22-09, 10:33 PM

Great prices on Antennacraft UHF TV parabolics on the auction site.

http://i.ebayimg.com/13/!BTn8RE!!2k~$(KGrHgoH-CsEjlLltsWbBKJ,yqpbGg~~_1.JPG

Antennacraft P-5 5 Foot Parabolic UHF Antenna Buy it Now $79, starting price $69, very reasonable shipping. 2 available.

Antennacraft P-7 7 Foot Parabolic UHF Antenna Buy it Now $129 plus shipping.

I am not affiliated with the seller.

willscary

06-22-09, 10:35 PM

systems2000

06-22-09, 10:59 PM

I acquired this today. I've never seen one before. Anyone know what it is?

dewster1977

06-23-09, 12:01 AM

I acquired this today. I've never seen one before. Anyone know what it is?

Don't know what it is I have seen two of those before, there use to be one on 494 just south of the Mason-Dixon line, I thin kthe other was around Frederick, don't know if either are still there. Appears to be for UHF. Be interesting to see how well it works.

johnpost

06-23-09, 12:09 AM

I acquired this today. I've never seen one before. Anyone know what it is?

give the story on the acquisition

300ohm

06-23-09, 12:46 AM

It seems that WPVI built a facility capable of 30 KW.
Hmm, I wonder if they got a new antenna and new antenna location too. It seems extreme signal meter jumping could be a sign of multipath, FWIR. I didnt have any ghosts on WPVI-TV channel 6 analog, but if the antenna / location has changed for digital, who knows ?

300ohm

06-23-09, 12:53 AM

I've never seen one before. Anyone know what it is?
Ive seen a few of those. (Jerrold as the manuf comes to mind, but I could be wrong) Its a horizontally stacked vee boom uhf lpda antenna from the early 1970's. (I actually built something similar back then out of copper wire. IIRC, results werent that impressive, and the thinking back then was that the vees should be on a 30 - 60 degree angle for uhf. The plans for the wire version may have even been in an issue of Pop Electronics ??) As you can tell from the really small front elements, that antenna was designed for the old ch 14 - 83 uhf band.

It looks like its in good shape. I would clean the connections and give it a try.

systems2000

06-23-09, 07:55 AM

Don't know what it is I have seen two of those before, there use to be one on 494 just south of the Mason-Dixon line, I thin kthe other was around Frederick, don't know if either are still there. Appears to be for UHF. Be interesting to see how well it works.
I acquired it from a house that was auctioned off and the new owners wanted the tower and all taken away. The house is located South of Mercersburg, just below the State Line. I don't have time at the moment, but I'll tell all later. :)

nordloewelabs

06-23-09, 10:27 AM

holl_ands

06-23-09, 10:44 AM

I acquired this today. I've never seen one before. Anyone know what it is?
That's a Quad ZIG-ZAG Log Periodic Array with Horiz. (only) Polarization,
used to feed a big Parabolic Dish, although they can also be used without the Dish:
http://www.ece.illinois.edu/about/history/antenna/photos.html#1
http://astro.berkeley.edu/~greg/log_periodic_feed.pdf
http://astro.berkeley.edu/~greg/ieee5.pdf
http://lea.hamradio.si/~s57uuu/mischam/logp110.pdf

Measure width (center-to-center) at front and back to determine half-wave lengths
and hence operating range:
http://www.onlineconversion.com/frequency_wavelength.htm

Welcome to the wonderful world of Zig-Zags....speaking of which.....

holl_ands

06-23-09, 10:50 AM

HI-VHF ZIG-ZAG LPA & FOLDED DIPOLE--Actual antennas, not just some models:

We finished installing 14-Element Zig-Zag Log Periodic Antenna in my son's attic (70-mi fm L.A.).
Started with STACKED configuration due to space, but will change to WEDGE (+1-2 dB).
I posted photos showing the simple build and install process...

Ch7 and Ch9 are OK but most of L.A. is waiting for Ch11 & Ch13 to "fix" their current problems.
He is only 2.7 miles from local low power Ch12, so it's gonna be dicey....stay tuned:
See photos in new update: http://www.imageevent.com/holl_ands/zigzaglpa
We fine tuned the antenna rotation to minimize Ch12 signal (20 dB null?), but to
obtain a weak enough signal, I had to insert about 30 dB of attenuation....after
bypassing Preamp.
We have a lot more work yet to do....install Risers for WEDGE, relocate up a little,
try it without a Preamp.....but mostly wait for Ch11 & Ch13 to fix THEIR problems.

While at his house, I had him do some 1/2-in pipe brazing for a FULL-BAND Hi-VHF Folded Dipole.
I'm going to use it as a "calibrated" 0 dBd Hi-VHF antenna for comparisons (no, not in his attic):
See photos in new update: http://www.imageevent.com/holl_ands/yagis

gjvrieze

06-23-09, 10:55 AM

I bought the last two Funke antennas that were new in package. I believe Garrett bought the last actual unit that had been opened. Midwest DXer was very reasonable. It is too bad that he could not have gotten a few more for others, as I am sure they would be hot sellers now with the digital VHF-hi problems some people are experiencing.

The Funke has about twice the gain of the Winegard from 7, 9 and 11, and seems to be even better on channel 13. It is a monster in length, but it is not very wide and is quite lightweight.

I truly wish someone could have modeled one of these. they are a fantastic VHF highband antenna.

Bill
Ya, I got the absolute last one. It is aimed at WKBT (RF channel 8) right now, the Winegard YA-1713 was getting dropouts and the Funke keeps a good lock on WKBT. (I have strong signal, but I am aimed right over a 91.7Mhz and 97.5Mhz 100kW FMs, which I can see at 6.3miles from the place where the Funke is mounted on the tower. Even with the FM trap on, I think I am fighting a bit of FM intermod from the harmonics and just SUPER strong signal from the FMs...

gjvrieze

06-23-09, 10:59 AM

I ended up getting another YA-1713, but I just remembered that there was another antenna that was once available, though not through retail outlets, the Funke PSP 1922:

http://www.funke.nl/library/1190_098502_psp1922_051203_790500985.pdf

I remember that MAX HD/Midwest Dxer had these, but that the last one sold a while ago.

With so many having problems with upper VHF, it would be nice to have these available again. Though, granted, many having problems are trying to use rabbit ears.

Still, I'm not sure I could manage a 13' antenna in the attic. ;)

It is a nice antenna. A little long though! (it is great outdoors though) It was little funke (pun intended) getting it to the top of my tower, it was pretty windy the day I did it, luckily, I had my dad stabilizing it with a lead line as it came up in the air. Very light weight, whoever designed it, did a great job!

nordloewelabs

06-23-09, 11:01 AM

HEDND

06-23-09, 11:02 AM

The antenna is a JFD Zig-a-Log UHF. I have a picture in a 1969 tv repair book by Art Margolis. I've seen a few of them stacked as that one is around Boston at one time.

holl_ands

06-23-09, 11:19 AM

PS: I measured Holland UVSJ: DC Pass Thru on VHF port, but not UHF Port.
And specs for Pico-Macom UVSJ says DC Pass Thru only on the VHF port.

What were they thinking???? I would think most people would want DC Pass Thru to their UHF Preamps!!!!!

[B]Does anyone know of a LOW LOSS VHF/UHF Diplexer (Combiner) with DC Pass Thru on UHF...or both ports????

Whatever....just means I have to relocate the Power Insertion Module to the attic.....

holl_ands

06-23-09, 11:24 AM

The antenna is a JFD Zig-a-Log UHF. I have a picture in a 1969 tv repair book by Art Margolis. I've seen a few of them stacked as that one is around Boston at one time.
Hmm, I bet it was covered by one of Paul Mayes patents:
http://www.library.illinois.edu/archives/uasfa/1106033.pdf

Trapezoidal Zig-Zags are here:
http://www.freepatentsonline.com/3550143.html

Triangular Zig-Zags are here:
http://www.freepatentsonline.com/3355740.html

holl_ands

06-23-09, 11:54 AM

@holl_ands: i made 3 Folded Dipoles of different sizes this weekend. all made of AWG 12. none did much for my situation. :( is the use of copper pipes a requirement for this kind of antenna?

btw, using K7MEM's (http://www.k7mem.*********/Electronic_Notebook/antennas/folded_dipole.html) calculator, i always get an impedance of 288 ohms. is that a major problem?

Edit: what about the spacing? if the antenna is made of a single material (AWG 12 wire), the spacing can be any, right? i used 1 inch spacing in all 3 i made.
The purpose of the Folded Dipole modeling exercise was to determine the useful
frequency range using various diameter elements....as a low gain alternative to those
pesky hi-VSWR Rabbit Ears.....

For a Folded Dipole cut to cover the whole Hi-VHF Band (192 MHz), VSWR using AWG12
was under 2.0 for Ch8-12 and rose to 2.5 for Ch7 and Ch13....so it's pretty good
but not quite as good as 1/2-in Copper Pipe (under 1.8).
And if you shortened the Folded Dipole, you could improve Ch13 a bit.

But a few tenths of a dB...or even several dB of signal strength aren't your problem.

What you need to do is to attenuate multipath reflections by adding a Reflector.....
& maybe a Director to form a 2 or 3-Element Yagi as discussed here:
http://www.wfu.edu/~matthews/misc/dipole.html

Or try some of the higher Gain antennas with good Front/Back Ratios,
such as K6STI's DIY 5-Element Yagi (about 32 x 32 inches) or some of the commercial
medium Gain Hi-VHF antennas discussed here and in EV's Indoor antenna thread,
such as EZ-HD (aka RCA ANT751) with 4-Elements for Hi-VHF....plus low gain UHF.

HEDND

06-23-09, 12:01 PM

Thanks for the links holl_ands. I see the JFD patent.

jspENC

06-23-09, 12:24 PM

nordloewelabs

06-23-09, 12:58 PM

What you need to do is to attenuate multipath reflections by adding a Reflector..... & maybe a Director to form a 2 or 3-Element Yagi as discussed here:
http://www.wfu.edu/~matthews/misc/dipole.html (http://www.wfu.edu/%7Ematthews/misc/dipole.html)

i'll try that.

[...]Gain Hi-VHF antennas discussed here and in EV's Indoor antenna thread, such as EZ-HD (aka RCA ANT751) with 4-Elements for Hi-VHF....plus low gain UHF.how does the CM2016 (http://www.solidsignal.com/prod_display.asp?PROD=CM2016&xzoom=Large#xview) compares to the RCA ANT751 on hi-VHF? what are the VHF elements in that pic? the 2 big angled ones in the back?

neilkaz

06-23-09, 01:11 PM

The antenna is a JFD Zig-a-Log UHF. I have a picture in a 1969 tv repair book by Art Margolis. I've seen a few of them stacked as that one is around Boston at one time.

One wonders how much gain that monster would have on UHF ?

Tower Guy

06-23-09, 02:26 PM

[BTW: I ordered Pico-Macom, but they substituted Holland....]

I always imagined that Holland was your company!

300ohm

06-23-09, 03:38 PM

One wonders how much gain that monster would have on UHF ?
Its not a particularly large uhf antenna. (driving by one you may miss it) Typical LPDA gains are from 10 - 11 dbi, so figure 2.5 - 3 tops dbi for stacking, giving about 14 dbi tops. Not really bad for its size and relative ease of manufacturing.

ProjectSHO89

06-23-09, 03:53 PM

Does anyone know of a LOW LOSS VHF/UHF Diplexer (Combiner) with DC Pass Thru on UHF...or both ports????

The Antennas Direct EU385CF is DC-PASS on the UHF port. VHF port is DC blocking.

dewster1977

06-23-09, 07:47 PM

I acquired it from a house that was auctioned off and the new owners wanted the tower and all taken away. The house is located South of Mercersburg, just below the State Line. I don't have time at the moment, but I'll tell all later. :)

Wasn't there A CM Color Vector 1210 or 1220 on that tower also? Bet that was fun to take down

baumgrenze

06-23-09, 08:09 PM

I'm having a problem with a classic FM antenna and birds. From time to time the local flock of rock doves decides to spend some time on my antenna. From time to time, either when the arrive or when the leave, one of them will knock an element askew and the reception suffers.

Does anyone know if the presence of birds on the antenna will cause a deterioration of reception?

As a first step I am considering just wrapping cable ties around the locks that are supposed to keep the elements deployed. I can see nothing wrong with this.

As a second step I am considering getting a couple of 1/4" weather resistant plastic rods and using cable ties to bind them to each element on both sides of the main boom. Is this worth trying, or might it interfere with reception?

As a final deterrent I am considering a set of plastic rods projecting upwards from the main boom over which I would drape some plastic monofilament bird netting normally used to protect fruit trees from birds. Is this worth trying, or might it interfere with reception?

Is there an antenna forum elsewhere on the web that might be a more appropriate place for this inquiry?

Thanks,

baumgrenze

EscapeVelocity

06-23-09, 08:17 PM

Get a .22 rifle and work on your aim.

Ba dum bump!

EscapeVelocity

06-23-09, 08:19 PM

This probably isnt the place to ask, but I am considering getting some wireless headphones. Is 95k hz or 2.3 ghz transmission better?

EscapeVelocity

06-23-09, 08:29 PM

EscapeVelocity

06-23-09, 08:39 PM

Finco FM-5 and Channel Master Probe 9

http://fmdx.usclargo.com/upclose.htm

holl_ands

06-23-09, 09:16 PM

i'll try that.

how does the CM2016 (http://www.solidsignal.com/prod_display.asp?PROD=CM2016&xzoom=Large#xview) compares to the RCA ANT751 on hi-VHF?
What are the VHF elements in that pic? the 2 big angled ones in the back?
CM2016 starts as a UHF Corner Yagi with 8+ Directors, similar to CM3016 front end,
except with only one of the big VHF elements remaining (and shortened to 47-in)
and the two rear most UHF elements extended for Hi-VHF range.

Hi-VHF elements are the two medium length elements just in front of the rear element.
From the picture, the rear element appears connected to the forward most of the two
Hi-VHF elements and the other is a passive Hi-VHF/UHF Reflector.

So for Hi-VHF, it's a 2-Element Hi-VHF Yagi "cell" with 8 overly small directors. Active
rear element will also contribute to Hi-VHF performance, seemingly a carry over from how
VHF elements are fed in CM3016....and I don't see any crossover as found in a Log-Yagi....
I would model it if someone has detailed dimensions rather than guessing the Gain.
[Maybe Ken Nist is already working on it......]

C-M specs for CM2016 say 0-2 dBd (2-4 dBi) for Hi-VHF and 7.7 dBd (9.9 dBi) for UHF:
http://www.channelmasterintl.com/documentation/catalogs/Channel%20Master%20Catalog_200903.pdf
CM2016 on pg1, CM3016 on pg7 and spec summary on pg19.
Note UHF Gain specs for CM2016 are same as CM3016....but not Hi-VHF....
[Although they don't say, I presume C-M continues to use dBd vice dBi.]

=======================================
RCA ANT751 has four Hi-VHF elements in a Log-Yagi configuration and
four more for UHF (and forward most Hi-VHF element is the UHF Reflector),
so it's basically a 5-Element Yagi on UHF, hence less powerful than CM2016.

NEC model says 5.5 dBi Gain for Ch7, raising to 7.5 dBi mid Hi-VHF band.
As I've said earlier, NEC model shows a gain drop across Ch12/13 that may
or may not be an approximation problem in the model (same problem as YA-1713).
I'm going to predict ANT751 has a little more Hi-VHF Gain than CM2016.

=============================================
Unfortunately, neither manufacture provides Front-to-Back Ratio specs, which is
even more important than Gain when fighting Multipath. NEC model for ANT751
shows excellent 17 dB F/B mid-band. Ch12/13 is much less, which may be a result
of the same NEC sim modeling problems mentioned above.

I wouldn't even guess at F/B for CM2016.....need detailed dimensions....

holl_ands

06-23-09, 09:33 PM

Which one of these antennas is likely to be best on UHF and on VHF hi?

http://www.millionbuyplus.com/images/products/BERANT104.JPG

http://www.ezsal.com/ebaypictures/5000_antenna.jpg

http://www.empresal.com/ebaypictures/antennanra3000B.jpg
NONE OF THE ABOVE (specs??? user reviews??? can't even tell if UHF and/or Hi-VHF....):
http://www.digitalhome.ca/forum/showthread.php?t=35083

300ohm

06-23-09, 09:43 PM

This probably isnt the place to ask, but I am considering getting some wireless headphones. Is 95k hz or 2.3 ghz transmission better?
Unfortunately, all the wireless headphones Ive had have been poor on bass and the very high notes, despite the specs. You should really try them in store.

EscapeVelocity

06-23-09, 09:49 PM

Yeah, Im not much on Wireless headphones, but Im looking for products to back up my hearing aid. Such as the TV Ears. Which have older models at 95k Hz and newer at 2.3Ghz. I think 95k Hz is infrared and thus is poor at penetrating walls and such (like a remote). 2.3Ghz (like newer cordless phones which also kept increasing the frequency) has better performance over distance and through walls.

EscapeVelocity

06-23-09, 09:51 PM

Thanks for the link! Great stuff 300ohm. Maybe I should sign up over there. Digitalhome seems to be my kind of people.

holl_ands

06-23-09, 10:00 PM

This probably isnt the place to ask, but I am considering getting some wireless headphones. Is 95k hz or 2.3 ghz transmission better?
http://www.goodcans.com/#wireless
http://www.consumersearch.com/wireless-headphones
http://www.audioholics.com/reviews/speakers/headphones/
Be sure to click on "Related Categories" (hmm....2007 is rather old):
http://www.onheadphones.com/wireless-headphones.html

BlueTooth is short range...and cheap means cheap....

900 MHz is pretty good...my analog Sennheiser's work through two walls
and are comfortable and light enough I can wear them for hours at a time.

2.4 GHz analog headsets were used before 900 MHz...so some are ANALOG,
but some of the better ones are DIGITAL:
http://www.amphony.com/download/pdf/dsheets/H1000.pdf
http://www.amphony.com/products/h2500.htm
http://www.ltbaudio.com/aboutproducts.html
http://www.sonystyle.com/webapp/wcs/stores/servlet/CategoryDisplay?catalogId=10551&storeId=10151&langId=-1&categoryId=3732

So the real question is which is better: ANALOG or DIGITAL.....should be no contest...

===================================================
PS: Yes, 95 kHz is infrared, so it's limited to line-of-sight vice 2.3 GHz wireless:
http://www.tvears.com/shopcontent.asp?type=tvears_whatis
Note the coverage specs for the 2.3 GHz wireless TVEars are LESS THAN 95 kHz "Original"....huh????
But TVEars Home Theater (95 kHz) Model covers entire house via a wireless repeater system:
http://www.tvears.com/shopexd.asp?id=5
https://www.tvears.com/compchart.html

EscapeVelocity

06-23-09, 10:07 PM

I used to be a Audiohaulic, however my ears arent what they used to be. Though I still enjoy donking around with vintage audio gear and esoteric and vintage speaker designs. Ive lost some ability to enjoy it.

For example, Beyerdynamic closed cans are my reference standard, because I can reallly push them and they can handle the bass that I through at them at 130db into the ear canal.

Severe to profound hearing loss one ear.....other ear completely deaf.

systems2000

06-23-09, 10:17 PM

Wasn't there A CM Color Vector 1210 or 1220 on that tower also? Bet that was fun to take down
Since the tower was a light duty one, I was lucky to find the owner had a man lift on the property and let us use it. :D

holl_ands

06-23-09, 10:58 PM

where i live (NYC), i get UHF stations *very* well, but Hi-VHF reception is really bad. today i'll order the CM 3010 StealthTenna for use indoors. i want an amp too and i wonder if i should go with:

a) CM3038 (15dB gain. designed for StealthTenna)
b) CM7777 (big favourite on AVForums)

suggestions?
The strong (nearly?) LOS signals from Empire State Bldg will overload hi-gain CM7777.

If you try anything, try 12 dB Gain W-G HDP-269, which has very high overload capability
and can be used with ANY antenna (unlike CM3038, which only plugs into StealthTenna):
http://www.winegarddirect.com/viewitem~d~Winegard-HDP-269-SquareShooter-PreAmplifier-for-SquareShooter-SS1000-(HDP269)~p~ANWHDP269.htm
http://www.amazon.com/dp/B001DFS4C2/ref=asc_df_B001DFS4C2827449?smid=A2NYACAJP9I1IY&tag=priceg-ce-20&linkCode=asn

dewster1977

06-23-09, 11:00 PM

Since the tower was a light duty one, I was lucky to find the owner had a man lift on the property and let us use it. :D

Was the VHF in good shape also?

holl_ands

06-23-09, 11:08 PM

I always imagined that Holland was your company!
No, although they are nearby (Ventura, CA), I have no affiliation with Holland Electronics LLC:
http://www.hollandelectronics.com/index.html

Nor do I have any affiliation with this or any other Holland property:
http://www.hollandcasino.nl/corporate/NL/default.htm

300ohm

06-24-09, 01:30 AM

From time to time the local flock of rock doves decides to spend some time on my antenna. From time to time, either when the arrive or when the leave, one of them will knock an element askew and the reception suffers.

Does anyone know if the presence of birds on the antenna will cause a deterioration of reception?
Well, yeah. You know that too, heh.

This may not be a solution for a whole flock, but a bird perch above the antenna may help. Ive noticed birds like to roost on the top most, comfortably sized for their feet, perch. A perch above the antenna is helpful for thin wire antennas like the GH and bowties.

14 X 14 bird netting is only $6 at Lowes (I just bought some for my raspberries), but you will need to build a frame around the antenna. Otherwise using the antenna as part of the net frame, they could still land on the ends, the highest leverage point for them to bend the elements.

Another trick used by sailboaters in dock is hanging a plastic owl so it swings in the wind from the highest point. Unfortunately, smart birds can get used to it though, heh.

Mylar tape or old AOL cd's strung together are another option, as some birds frighten from moving shiny things.

nordloewelabs

06-24-09, 05:09 AM

RCA ANT751 has four Hi-VHF elements in a Log-Yagi configuration and four more for UHF (and forward most Hi-VHF element is the UHF Reflector), so it's basically a 5-Element Yagi on UHF, hence less powerful than CM2016.

[...]

I'm going to predict ANT751 has a little more Hi-VHF Gain than CM2016.

now i'm confused.... :confused:

holl_ands

06-24-09, 09:22 AM

ANT751 appears to be a bit better than CM2016 on Hi-VHF
but it's UHF section doesn't appear to be as good as the CM2016.

So ANT751 is better choice for solving your Hi-VHF problem and BOTH
are a big step up from a RabbitEars (e.g. HDTVa) or StealthTenna.

UHF Gain for either is a lot better than a Loop or StealthTenna.
And if anyone needs more Gain, a UHF only antenna can be added later via UVSJ combiner.

Since you said you face AWAY from the Empire State Bldg, the best signal may or
may not be coming from that direction, trying to propagate THROUGH you building.
However, it is also likely the best signal is reflecting off the hills further away, so
pointing the antenna out your window may work better, attenuating the signal
that goes through the building. The combination of the two signals is Multipath.
Another complication, "best" signal direction for Hi-VHF may or may not be same as UHF.

PS: Last night CH11 and CH13 in Los Angeles finally got their transmitters working
the way they should.....ESB is probably having similar transmitter start up problems....

nordloewelabs

06-24-09, 02:35 PM

So ANT751 is better choice for solving your Hi-VHF problem and BOTH are a big step up from a RabbitEars (e.g. HDTVa) or StealthTenna.

UHF Gain for either is a lot better than a Loop or StealthTenna.

very well laid out! thanks a lot!

i found a new "sweeter spot" for Ch-13 (my favourite Hi-VHF channel) last night!!! in it, i got an astounding 70% strength! on the previous sweet spot i could only get 40% -- and that at night on clear-sky days! the plot thickens! after 2 weeks moving commercial and home-made antennas around the apartment, i realize that there is enough signal for Ch-13 (PBS), but it can only be received at this *VERY* particular spot:

- hanging on a cabinet door;
- 1 ft off the floor;
- facing a wall;
- 3 ft away and pointing 45-deg away from aforementioned wall;
- in the middle of the freaking kitchen;
- using a home-made 12-AWG Folded Dipole!!! <-- thanks, holl_ands!

this location is both crazy and unfeasible! i feel better now because i know that the signal is ok in the area, but for some reason, it's not easy to get it! it might have something to do with the nature of Hi-VHF and the digital format... (?)

i may post pictures of this new-found "sweeter spot" later today.

PS: Last night CH11 and CH13 in Los Angeles finally got their transmitters working
the way they should.....ESB is probably having similar transmitter start up problems....do you know exactly what happened? which changes were made? i called Ch-13 (PBS) twice yesterday and asked them whether there were any plans to boost the station's transmission power. i also sent them an email (all three contacts were made before i found the "sweeter-spot"). here are their answers:

PBS Reps on the phone: No. The signal strength wont be increased any further.
PBS Rep via email: We have been working with the FCC to determine why certain people are having persistent problems.

Don F.

06-24-09, 04:43 PM

:mad:I think you are going to have problems with the VHF at 65 miles away with the C4.

After reading several opinions on the c4 I was ready to cancel, but it had shipped.... the thing arrived today, and was high up on the pole within a couple of hours.... It is now back in the box and will be headed north tomorrow. Before installing, I took some signal strength readings from my

cm4228.
Channel 13.....88, channel 9.......66, channel 7.......57

C4
Channel 13.....36, channel 9.......0 channel 7....... 0

neither antenna was amped... I beleive Antennas Direct should take another look at the 12db gain across the hdtv band.... I don't think it has that much horsepower. I wanted to pass on my findings, next time I will read more before I buy.....

ProjectSHO89

06-24-09, 05:03 PM

:mad:

After reading several opinions on the c4 I was ready to cancel, but it had shipped.... the thing arrived today, and was high up on the pole within a couple of hours.... It is now back in the box and will be headed north tomorrow. Before installing, I took some signal strength readings from my

cm4228.
Channel 13.....88, channel 9.......66, channel 7.......57

C4
Channel 13.....36, channel 9.......0 channel 7....... 0

neither antenna was amped... I beleive Antennas Direct should take another look at the 12db gain across the hdtv band.... I don't think it has that much horsepower. I wanted to pass on my findings, next time I will read more before I buy.....

At more than 65 miles away, WTH were you thinking ordering a UHF antenna when you already had a UHF antenna that wasn't doing the job on high-VHF?.... Order a VHF antenna, for goodness' sake.

Like any other UHF antenna, it won't have the same reception on the VHF band, especially with the greatly reduced VHF power these guys are now running....

300ohm

06-24-09, 05:34 PM

this location is both crazy and unfeasible!
Heh, thats typical for a hot spot. There must be a law of physics that explains why that is, he-he.

Don F.

06-24-09, 06:18 PM

[QUOTE=ProjectSHO89;16714049]At more than 65 miles away, WTH were you thinking ordering a UHF antenna when you already had a UHF antenna that wasn't doing the job on high-VHF?....

I have a high vhf antenna and a 91xg going into a 7777 that does a good job... I just thought the c4 may be able to pull in the high vhf and uhf in the same unit as the company says.

The cm 4228 is on the hobby side of life, and is not my primary system, even so it will hold the vhf channels very well, at 65 miles out. I have good elevation...

Falcon_77

06-24-09, 09:17 PM

do you know exactly what happened? which changes were made?

KTTV/11 and KCOP/13 filings suggest that they moved from Aux facilities to their main facilities for upper VHF 11 and 13.

WABC and WNET have already filed Licenses to Cover for their main facilities. No such filing appears for WPIX/11 yet, so perhaps they have more work to do.

rviele

06-24-09, 10:27 PM

EscapeVelocity

06-24-09, 10:36 PM

I not old, just deaf. I actually have pristine cochlea and nerves on my one ear that I now use hearing aids in. Eventually Ill get a mechanical implant and have my hearing restored in that ear, to pretty much good as new, hopefully. The other ear is shot.

nordloewelabs

06-24-09, 11:50 PM

sorry to ask again. i'm trying to understand the jargon and processes behind this thing. please, bear with me.

KTTV/11 and KCOP/13 filings suggest that they moved from Aux facilities to their main facilities for upper VHF 11 and 13.

so what you mean is that they shut off the analog broadcast that was taking place at the main facility and continued to broadcast in digital from the auxiliary one? and finally, this weekend, they returned to their main facility to -- for the first time -- broadcast in digital?

WABC and WNET have already filed Licenses to Cover for their main facilities.

in other words, they are *still* operating from their auxiliary facilities, but have already filed for a move to main one? is that what you meant?

PCTools

06-25-09, 12:18 PM

ProjectSHO89

06-25-09, 12:49 PM

systems2000

06-25-09, 02:18 PM

Was the VHF in good shape also?
A couple of the front elements were broken off. I also snagged a pre-amp, 300 Ohm VHF/UHF combiner, and an FM antenna (bottom broken - possibly rebuildable).

holl_ands

06-25-09, 02:46 PM

Why are those 4 way combiners so expensive and rare to find? I was going to do a quad stack and see they want around $100. Jeez...

What about a standard combiner for UHF and VHF? Is it possible to use a splitter backwards to add a UHF and VHF together into a downlead?

Thanks!
Yup, 4-way Wilkinson Stripline Combiners are well over $100 now....if you can locate one:
http://www.avsforum.com/avs-vb/showthread.php?p=16072450
As you can see, very few cover either entire Lo-VHF, Hi-VHF or UHF band
and there are NONE that operate across more than one of these bands.

Standard 2-Way RF Splitter/Combiner is a Hybrid Transformer with 3.5-4.5+ dB loss
and 4-Way is twice that (7-9+ dB).
VHF/UHF Diplexer (aka Combiner) has 0.5-1.0 dB loss, cuz it uses Band Pass Filters instead.
http://www.avsforum.com/avs-vb/showthread.php?p=16273089

Pico-Macom and Holland UVSJ VHF/UHF Combiners ($3) have DC PASS thru only on VHF side:
http://yhst-18278607509093.stores.yahoo.net/products-distribution-passive-component-separators-combiners.html
http://www.hollandelectronics.com/catalog/upload_file/Filters-Diplexers.pdf

Antennas Direct EU-385-CF VHF/UHF Combiner reportedly has DC PASS only on UHF side:
http://www.antennasdirect.com/antenna_combiner.html
http://www.solidsignal.com/prod_display.asp?PROD=ANTDRCT-COMBNR

300ohm

06-25-09, 04:33 PM

Standard RF Splitter/Combiner is a Hybrid Transformer with 3.5-4.5+ dB loss.
Yeah, and thats if they mark the specs. If not not, add a good db more. 4 ways are very very miserable. Old timey Channel Master 300ohm 2 set couplers ganged (in reversed and weatherproofed) may do a lower loss job, if you can find them in a flea market. (lucky I have such crap for my experiments, heh)

I was going to do a quad stack
Quad Horizontal Stack of XG-91's ?

rbarbier

06-25-09, 06:26 PM

Using the separate inputs of your 7777 is the best way to go. Don't forget to flip the necessary switch.

Those TVfool numbers are much better (about 20 dB) than where I tested a couple of weeks ago. I'd expect pretty good results.

Just got the C5 installed. Ran it into my 7777 VHF port. Made sure the switch is on for "separate". Still getting 0 signal on 7, 9, 11 and 13. I have it facing the same direction as my C4 and I am getting great signal on UHF. Looks like I will try moving the antenna around but this does not look good. Might have to send it back to Antennasdirect.

dewster1977

06-25-09, 06:40 PM

A couple of the front elements were broken off. I also snagged a pre-amp, 300 Ohm VHF/UHF combiner, and an FM antenna (bottom broken - possibly rebuildable).

You should be able to add to your tower now.

Tower Guy

06-25-09, 06:53 PM

Just got the C5 installed. Still getting 0 signal on 7, 9, 11 and 13.

Two things to check.

The VHF stations are not in the same heading as the UHF station, re-aim.
Try the antenna directly to the TV to see if the preamp is defective on VHF.

rbarbier

06-25-09, 07:09 PM

Two things to check.

The VHF stations are not in the same heading as the UHF station, re-aim.
Try the antenna directly to the TV to see if the preamp is defective on VHF.

I tried the C5 antenna directly to my TV and the same thing (no signal on 7, 9, 11 or 13). What is funny is that I am getting a good enough signal with the C5 for channel 36 directly to my TV. With the C4 through my 7777, I get about 80 signal. With the C5 directly to my tv without the 7777, I get about 50 signal on UHF 36. I will try adjusting the antenna. I just though that since all my towers are at the same degrees (UHF/VHF), I shouldn't have to have a different direction.

ProjectSHO89

06-25-09, 10:22 PM

...
Antennas Direct EU-385-CF VHF/UHF Combiner reportedly has DC PASS only on UHF side:
http://www.antennasdirect.com/antenna_combiner.html
http://www.solidsignal.com/prod_display.asp?PROD=ANTDRCT-COMBNR

The Rat Shack 15-2586 UVSJ is also DC Pass on the UHF leg. I have one on my desk right now.

holl_ands

06-25-09, 11:33 PM

Too bad R-S doesn't bother to provide isolation or insertion loss specs for 15-2586....

ProjectSHO89

06-26-09, 06:48 AM

Too bad R-S doesn't bother to provide isolation or insertion loss specs for 15-2586....

Yeah, that would be nice.

However, for consumer-grade stuff, if it's "good enough" not to get returned, that's all it takes.

rbarbier

06-26-09, 09:10 AM

I tried the C5 antenna directly to my TV and the same thing (no signal on 7, 9, 11 or 13). What is funny is that I am getting a good enough signal with the C5 for channel 36 directly to my TV. With the C4 through my 7777, I get about 80 signal. With the C5 directly to my tv without the 7777, I get about 50 signal on UHF 36. I will try adjusting the antenna. I just though that since all my towers are at the same degrees (UHF/VHF), I shouldn't have to have a different direction.

After moving my C5 higher, I am very close to having reception on 9 and 11. 13 is right there but isn't perfect. Still no sign of 7. On my TV tuner, I only need above 35 for UHF for a perfect picture (of course I want to be higher). It seems that with the High VHF channels, I need to be above 45 for a perfect picture. I am right around 44 signal for 13 and 40 signal for 9 an 11 and still 0 for 7. Should I just wait until Los Angeles increases the power for these channels or would a better Pre-Amp for VHF (instead of the 7777) help? I am so close right now. I would like to be at least 20% higher on my signals.

neilkaz

06-26-09, 11:29 AM

After moving my C5 higher, I am very close to having reception on 9 and 11. 13 is right there but isn't perfect. Still no sign of 7. On my TV tuner, I only need above 35 for UHF for a perfect picture (of course I want to be higher). It seems that with the High VHF channels, I need to be above 45 for a perfect picture. I am right around 44 signal for 13 and 40 signal for 9 an 11 and still 0 for 7. Should I just wait until Los Angeles increases the power for these channels or would a better Pre-Amp for VHF (instead of the 7777) help? I am so close right now. I would like to be at least 20% higher on my signals.

It seems to me that you are the guinea pig for the new C5 and that with it just being a loop in front of a reflector (and a reflector that isn't that large for VHF-HI) it doesn't have enough gain for your needs.

I'd try a YA-1713 if I were you as they have a couple/few dB more gain on VHF-HI and are a tried and proven antenna.

The C4, however, is a good antenna and is essentially 4 loops, so it has decent gain for UHF, and people are doing well with it.

.. neilkaz ..

rbarbier

06-26-09, 11:33 AM

It seems to me that you are the guinea pig for the new C5 and that with it just being a loop in front of a reflector (and a reflector that isn't that large for VHF-HI) it doesn't have enough gain for your needs.

I'd try a YA-1713 if I were you as they have a couple/few dB more gain on VHF-HI and are a tried and proven antenna.

The C4, however, is a good antenna and is essentially 4 loops, so it has decent gain for UHF, and people are doing well with it.

.. neilkaz ..

I am sure the YA-1713 would work for me. I live in an Apartment though and I am trying to keep the antenna size small enough. Yes, I do have my own balcony and it is on a tripod in the air, but I am not sure how they would react to a 100" antenna there. I know the FCC rules and everything but I just don't want problems. The C4 and C5 don't stand out as much.

Digital Rules

06-26-09, 12:07 PM

I am sure the YA-1713 would work for me.
Not sure if the 6" long Antennacraft Y5-7-13 is an option for you? It is light years better on VHF-HI than the C-4, or 5.

rbarbier

06-26-09, 12:13 PM

Not sure if the 6" long Antennacraft Y5-7-13 is an option for you? It is light years better on VHF-HI than the C-4, or 5.

Yeah...I was looking at that one also. It is only 5' so it is smaller then that other one. I would be able to "hide" that one easier. If I can't get the C5 working, I will probably get the Y5-7-13 and keep the C4 for the UHF.

nordloewelabs

06-26-09, 11:15 PM

i'm looking for ideas for an "indoor mast". i have a 3-way lamp but that doest give me enough flexibility height-wise. i'd like to get something that is at least 7ft high so i can hang a CM2016 (http://www.solidsignal.com/prod_display.asp?PROD=CM2016&xzoom=Large#xview) nearer the ceiling and out of the way -- even though i might have to lower the antenna eventually.

any ideas? it also has to be something that stays up on its own legs and can be easily found online or in stores. you know, something simple. if there's nothing like it, i'll use the 3-way lamp.

thanks in advance.

EscapeVelocity

06-26-09, 11:21 PM

You can get a hand towel holder (like for the bathroom) and mount if vertical on a wall and mount the antenna to that.

nordloewelabs

06-26-09, 11:30 PM

You can get a hand towel holder (like for the bathroom) and mount if vertical on a wall and mount the antenna to that.

well, i cant drill the walls either. a curtain rod wouldnt work because it can only be put between two walls. so it really must be something that stands on its own legs/base.

johnpost

06-26-09, 11:36 PM

well, i cant drill the walls either. a curtain rod wouldnt work because it can only be put between two walls. so it really must be something that stands on its own legs/base.

depends on what you want to look at or buy or build.

a patio umbrella stand will hold a pole to mount an antenna on and will not tip over. a coat tree will hole a pole that might not tip over, might be better if you add weight near the base. a flag pole stand might be between those to in looks and function.

nordloewelabs

06-26-09, 11:44 PM

i dont want to build anything. i'm currently browsing Amazon trying to find something that is tall enough. they have lots of floor lamps but they arent tall enough to keep the antenna near the ceiling.

i saw poles at Amazon but couldnt figure out a way to keep one standing.

systems2000

06-27-09, 12:42 AM

Try looking in the bath section of Wal-Mart for an adjustable shower curtain rods. I use them in the laundry room to hang clothing, when I remove them from the dryer. I also have mounted one above the shower head for extra towel draping and the wife uses it for her delicates.

nordloewelabs

06-27-09, 12:52 AM

Try looking in the bath section of Wal-Mart for an adjustable shower curtain rods.

seems to be a good idea. i wouldnt use it horizontally (like in the bathroom) because it would limit my ability to move the antenna around. i wonder if it would be strong enough to bear the weight of the antenna when setup vertically (against the floor and ceiling). i guess that, if i got one with flat ends, that would increase the adherence to the floor and ceiling.

systems2000

06-27-09, 12:55 AM

I did a continuity test on the Zig-Zag antenna I acquired and found that the four sets of Zig-Zag's are all electrically connected through the rear cross-bracing. I can actually place the multi-meter leads on both terminals of the 300 ohm connection and get continuity.

I don't think this is supposed to happen. If I mount the antenna to a grounded mast, the signal will go to ground. :(

I'm also wondering if there should be a reflector or grounded backplane.

systems2000

06-27-09, 12:58 AM

seems to be a good idea. i wouldnt use it horizontally (line in the bathroo) because it would limit my ability to move the antenna around. i wonder if it would be strong enough to bear the weight of the antenna when setup vertically (against the floor and ceiling). i guess that, if i got one with flat ends, that would increase the adherence to the floor and ceiling.
Depends upon how much you turn the rods to apply pressure. The one I have in the laundry room spans both the washer and dryer and is completely packed with clothes on hangers. Even several heavy Winter military jackets.

systems2000

06-27-09, 09:25 AM

I hope I get this right.

I took some measurements of the Zig-Zag and this is what I came up with:

12 Zags / arm mounted to plastic square tubes
Gross Size (Frame): 29.25" x 29.25" x 43" (back dimension x back dimension x back to front)
Front Gross Size: 6" x 2"
300 Ohm Feed Point: 3" forward of Zig-Zag elements (with 5" feed wire to Zig-Zag elements (x4))
Feed End (at Zig-Zag): 4.5" x 8.25"
Resistance From Front of Zig-Zag to Rear Frame: 74 ohms
Rear - Outside to Outside of Zig-Zag element (L to R): 38.5"
Front - Outside to Outside of Zig-Zag element (L to R): 10.75"
Center to Center of Zig-Zag Elements (Rear L to R): 27.25"
Center to Center of Zig-Zag Elements (Rear T to B): 27.75"
Center to Center of Zig-Zag Elements (Front L to R): 7.375"
Center to Center of Zig-Zag Elements (Front T to B): 4"
Zig-Zag Length (F to B): 38.5"
Zig-Zag Width (F to B): 0.375" to 0.875"
Zig-Zag Element Placement: 4.5" from front and 2.25" from rear
Length of First Zig (End - End): 1.625"
Length of Last Zag (End - End): 6.6875"

nybbler

06-27-09, 10:41 AM

I did a continuity test on the Zig-Zag antenna I acquired and found that the four sets of Zig-Zag's are all electrically connected through the rear cross-bracing. I can actually place the multi-meter leads on both terminals of the 300 ohm connection and get continuity.

Means nothing. A folded dipole is the same way. Almost any antenna is either a dead short or an open circuit to DC (the exceptions aren't common in TV antennas). An LPDA (and thus probably an LPZA) can be done either way.

Mister B

06-27-09, 10:46 AM

When I lived in an apartment my ceiling was too high for a shower rod to span the distance between the floor and ceiling. I found an expandable paint brush handle (used for painting high walls) at the hardware store which was long enough to extend to a height that it could be wedged in between the carpet and a small piece of foam rubber to protect the ceiling.

systems2000

06-27-09, 11:56 AM

Means nothing. A folded dipole is the same way. Almost any antenna is either a dead short or an open circuit to DC (the exceptions aren't common in TV antennas). An LPDA (and thus probably an LPZA) can be done either way.
So explain to me how the signal doesn't just go to ground when the antenna is mounted. Every antenna I've seen is electrically isolated from the grounded tower.

Clarification: The continuity is being caused by all four elements being riveted to the back mounting frame.

300ohm

06-27-09, 12:42 PM

So explain to me how the signal doesn't just go to ground when the antenna is mounted. Every antenna I've seen is electrically isolated from the grounded tower.
My CM1221 is the same way, the vertical boom in the back is electrically connected to both horizontal booms, resulting in a dead short across the twin lead. It is isolated from the mast though, so I can see your point. Have you tested it out on a grounded mast ? Some lpda's will have an open circuit. Think of it this way, both booms are really acting as one, whether they are open or short circuited. And the signal eventually does go to a ground.

I took some measurements of the Zig-Zag and this is what I came up with:
Good start. For modeling, more measurements would be needed.

1) How thick is the zig-zag material ?
2) How wide is each individual zig-zag leg ? They look to be all the same width ?.
3) Would need cummulative distances of one zig-zag. (all 4 look to be exactly the same ?)
Measure the cumulative distance of the right side sharp points, starting at the back (away from the transmitter) and going to the front.
Measure the cumulative distance of the left side sharp points, starting at the back (away from the transmitter) and going to the front.
Also, at all those above points, the total horizontal width of the zig-zag at that point. You can do that by holding a flat edge against one side of the zig-zag element.
Basically, a graph paper drawing would be needed.

ProjectSHO89

06-27-09, 01:25 PM

So explain to me how the signal doesn't just go to ground when the antenna is mounted. Every antenna I've seen is electrically isolated from the grounded tower.

What is important is that the DRIVEN ELEMENT is not shorted to ground at RF frequencies.

The boom, reflectors, and directors are commonly in direct contact with the mast.

systems2000

06-27-09, 02:28 PM

What is important is that the DRIVEN ELEMENT is not shorted to ground at RF frequencies.

The boom, reflectors, and directors are commonly in direct contact with the mast.
There are no reflectors or directors and as posted earlier, the booms are plastic square tubes. The Zig-Zag elements are riveted to the back bracing, which had "U" bolts (one in the upper brace and one in the lower brace) to clamp to the tower.

systems2000

06-27-09, 02:47 PM

Think of it this way, both booms are really acting as one, whether they are open or short circuited. And the signal eventually does go to a ground.
There are four booms. The bootom two booms are bonded to one side of the 300 Ohm wing nut and the top two booms are bonded to the other side of the wing nut.

Good start. For modeling, more measurements would be needed.

1) How thick is the zig-zag material ?
2) How wide is each individual zig-zag leg ? They look to be all the same width ?.
3) Would need cummulative distances of one zig-zag. (all 4 look to be exactly the same ?)
Measure the cumulative distance of the right side sharp points, starting at the back (away from the transmitter) and going to the front.
Measure the cumulative distance of the left side sharp points, starting at the back (away from the transmitter) and going to the front.
Also, at all those above points, the total horizontal width of the zig-zag at that point. You can do that by holding a flat edge against one side of the zig-zag element.
Basically, a graph paper drawing would be needed.
1) 1/16"
2)It tapers from narrow to wide (front to rear). As posted earlier - Zig-Zag Width (F to B): 0.375" to 0.875"
3)They are:
LEFT (From Rear C-C): 35.375" (35-3/8")
RIGHT (From Rear C-C): 34.3125" (34-5/16")

I did notice that the points are not linear from front to back. They seem to make a concave curve. Graphing would be the best option. Maybe I can use some easel paper and lay the element down and trace it.

systems2000

06-27-09, 04:31 PM

Before I get to the table, the elements are alternating zigs and zags, as you go around the four corners (ie. starts left, then right, then left, then right). There's also another interesting effect that I just noticed, the zig or zag is parallel to the backplane. The top right (looking from the rear) produces a parallel at the start, while the top left produces the parallel after the first bend. This also alternates.

Length (starting at rear)|Width|Rivet|Joint
6-23/32" (Half)|0.875"|X|X
12-1/4"|13/16"||
11-9/16"|3/4"|X|
10-29/32"|11/16"||
10-9/32"|5/8"||
9-11/16"|5/8"|X|X
9-1/8"|5/8"||
8-19/32"|9/16"||
8-1/16"|9/16"|X|
7-5/8"|17/32"||
7-5/32"|1/2"||
6-3/4"|15/32"||
6-5/16"|7/16"|X|X
5-15/16"|7/16"||
5-9/16"|7/16"||
5-1/4"|3/8"|X|
4-27/32"|3/8"||
4-9/16"|3/8"||
4-1/4"|3/8"||
3-15/16"|3/8"|X|
3-21/32"|3/8"||
3-7/16"|3/8"||
3-3/8"|3/8"||
3"|3/8"||
1-5/8" (Half)|0.375"|X|X

nybbler

06-27-09, 10:00 PM

So explain to me how the signal doesn't just go to ground when the antenna is mounted. Every antenna I've seen is electrically isolated from the grounded tower.

I'm not an RF engineer, but I think this will only be a problem if there's also a path to ground through the feed. There's another thread about baluns where it's noted that some of them have a direct connection between input and output and some don't. If there's a path to ground through both element and feed, I believe the feedline and the mounting structure become part of the antenna, which is not going to help anything.

rbarbier

06-27-09, 10:35 PM

Ok...

After playing with my C5 a little bit more (moving it around), I am very close to getting channel 9, 11 and 13. I have just enough signal for a picture but any little drop in signal and it will drop enough to lose signal. I am using the 7777 with the C4 going into the UHF and the C5 going into the VHF. If I change to the Winegard AP 2880, will this get me where I need to be? I am really good with the UHF I just need a little more for the VHF. I have a feeling that when/if the LA stations increase the power, I will be better.

Thanks.

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d618a23d52b0c16

nordloewelabs

06-27-09, 10:41 PM

After playing with my C5 a little bit more (moving it around), I am very close to getting channel 9, 11 and 13.

the secret is: a "sweeter spot" is just a few inches away.
http://www.avsforum.com/avs-vb/showpost.php?p=16713017&postcount=9707

systems2000

06-28-09, 01:16 AM

I discovered an interesting feature of my setup this evening. To get WLYH-DT at 66.3° True (from FCC database), I need to set my antenna on a -90° heading from 66.3°. This is the only station that I have to do this with.

Is it possible to get that strong of a multi-path off the Tuscarora Ridge, that it drowns out the 2-edge direction? My reception is solid (on all CECB's) at 70% SS and 24% SQ on my ZAT-970A.

300ohm

06-28-09, 02:04 PM

I discovered an interesting feature of my setup this evening. To get WLYH-DT at 66.3° True (from FCC database), I need to set my antenna on a -90° heading from 66.3°. This is the only station that I have to do this with.
On the zig-zag uhf antenna ? That is weird, as the antenna should have a null there. Is the station too strong ? I can occasionally get WLYH-DT way down here.

dewster1977

06-28-09, 02:19 PM

systems2000

06-28-09, 10:54 PM

On the zig-zag uhf antenna ?
No. The CM3020.

I haven't mounted the Zig-Zag yet.

Is the station too strong ?
I don't think so, I have stronger that don't produce this effect.

systems2000

06-28-09, 11:00 PM

I tried the same thing 90° off and get both WLYH and WHP great that way
So it's not just me? As for WHP-DT, all I get on 21 is WVPY-DT.

dewster1977

06-28-09, 11:39 PM

So it's not just me? As for WHP-DT, all I get on 21 is WVPY-DT.

I use to get WVPY all the time till WHP went back to 21, although this afternoon, I got WGAL, WLYH and for the first time WPMT, WJZ is pretty good now they increased power.

300ohm

06-29-09, 10:14 AM

WJZ is pretty good now they increased power.
Ill have to do a rescan for it after I turn the antenna. Do you know if WBAL channel 11 increased power ? They were slated for 5KW last September (WJZ channel 13 was allocated 25KW at the time), which is just plain ridiculous, heh.

Digital Rules

06-29-09, 10:28 AM

Ill have to do a rescan for it. Do you know if WBAL channel 11 increased power ? They were slated for 5KW, which is just plain ridiculous, heh.No, still @ 5kw. They haven't applied for a power increase AFAIK. I'm finding reliable reception limited to around 45-50 miles with a 10 db gain antenna. Over 50 miles is pretty much tropo only unless you have a considerable terrain advantage.

Konrad2

06-29-09, 01:32 PM

> i'm looking for ideas for an "indoor mast". i have a 3-way lamp
> but that doest give me enough flexibility height-wise. i'd like
> to get something that is at least 7ft high so i can hang a
> CM2016 nearer the ceiling and out of the way

Assuming an 8 foot ceiling: see if you can find a spring-tension
pole, perhaps as part of a lamp. Probably not a good choice if
the ceiling is suspended. With a suspended ceiling, just hang
it from the grid.

A pole plus a automotive scissors jack. (Be careful to avoid
punching a hole in the ceiling!)

Mount a pole in a Christmas tree stand.

A large plastic tub full of dirt, sand, or rocks would support a pole.
For extra credit plant some flowers or tomatoes.

Those standalone basketball stands, although many will be too large.
Maybe they make a smaller version for little kids?
Maybe they sell standalone tetherball poles? volleyball, badmitten, ...

Pipe: get some threaded steel plumbing pipe and some tees.
You could make a shiny version using copper. Would PVC be
strong enough?

Build something out of 2x4s

concrete pier support with bracket for mounting a 4x4
(hide the ugliness with a Christmas tree skirt type cloth)

patio umbrella stand

camera tripod

Put a cabinet/dresser/shelves there and fasten pole to the back
of it.

Put a tall bookcase there and set antenna on it.

They sell hooks for holding hanging plants. Leave the hook
when you move, or fill hole with spackle and then paint it.
(assuming plaster or sheetrock ceiling)

slush1422

06-29-09, 01:38 PM

326 pages in this forum is a lot to go through. I cant tell if I need two antennas or can do just one? We currently have a set top indoor antenna and want to upgrade to an outdoor roof mounted one. Living in the Los Angeles area, we have experienced the same thing others have where we lost channels 7-13. Any suggestions for a one antenna solution that will get 7-13 well as other stations? Here is my info from TV Fool:

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d618ab3c4be902a

etcarroll

06-29-09, 01:42 PM

Before I mounted my CM4228, I had a temp mounting of a broom handle in a patio umbrella stand, it worked very nicely.

EscapeVelocity

06-29-09, 01:46 PM

Microphone stands

nordloewelabs

06-29-09, 03:20 PM

thank you all for the suggestions! as of now, i'm more inclined to get a strong and stretchable curtain rod. btw, i just ordered the CM2016 (http://www.solidsignal.com/prod_display.asp?PROD=CM2016&xzoom=Large#xview) and the HDP-269 (http://www.solidsignal.com/prod_display.asp?prod=ANWHDP269) amp. this amp was recommended by holl_ands as a way to avoid overload of my CM-7000 converter. i have a 37" Olevia LCD too so i'll split in 2 the signal received by the antenna.

DieterW

06-29-09, 04:57 PM

Here's my TVFool.com info (sorry the link doesn't work -- new member and therefore no URLs allowed):

Paste the string to the end of www . tvfool . com

/?option=com_wrapper&Itemid=29&q=id%3d618ac14ba8610a

I am mainly interested in the (closer and higher-power) ATSC/DTV stations that are at 180-185 degrees. All are UHF except for Fox which is at 7. Most are ~15 miles away.

This will be installed in the attic, with about a 100 foot run (RG6) to a 4-way splitter. I was looking at the Winegard AP-8700 pre-amp. (apparently the CM 7777 is really popular, too. Any preferences???)

For the antenna, I was considering the ANT751/EZ-HD, the 7694P, maybe the CM 2016, or even the UP-7 from Denny's. The EZ-HD looks nice due to its small size, but the 7694 seems to be really popular. EDIT: Also maybe the AntennaCraft HBU22???

I currently have the SS-3000 inside (not in the attic) and it works pretty well except for a couple of channels occasionally dropping out. But, I would like a more consistent signal on all channels and I'm willing to pay for it.

Also, does anybody know if you need to lightning ground the antenna if it's in the attic? Do you have to go all out crazy or can you just ground it to something grounded in the attic just to dissipate static buildup?

Thanks in advance!

rabbit73

06-29-09, 06:06 PM

Welcome to the forum Dieter.

Here is your tvfool report:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d618ac14ba8610a

The CM7777 is too much for your strong signals. The 8700 might be too much, maybe just the HDP269 to make up for coax and splitter loss. The loss caused by an attic vs outside is difficult to predict.
Also, does anybody know if you need to lightning ground the antenna if it's in the attic? Do you have to go all out crazy or can you just ground it to something grounded in the attic just to dissipate static buildup?
Here is a thread about grounding an attic antenna:
Need to Ground an Attic Antenna? http://www.avsforum.com/avs-vb/showthread.php?t=1016115

I'll leave it to the big guns to give you further advice.

nordloewelabs

06-29-09, 06:13 PM

I currently have the SS-3000 inside (not in the attic) and it works pretty well except for a couple of channels occasionally dropping out. But, I would like a more consistent signal on all channels and I'm willing to pay for it.

with the SS-3000, which channels are unstable and which ones you can not receive at all?

300ohm

06-29-09, 08:33 PM

No, still @ 5kw. They haven't applied for a power increase AFAIK.
Jeez, heh. I guess they just dont want the business.

On another note, Im now getting WPVI channel 6, after they quadrupled power, with my garage antenna, currently my foldable reflector-less single bay GH version. (when folded, it fits easily in my pocket, heh) Modeling shows 1.88 dBi raw gain with a 48.9 SWR on channel 6 with that uhf only antenna, heh. Net Gain, of course, is far far into the negative numbers. There are drop outs though, but its still oddly fairly consistant.

Jim Miller

06-29-09, 09:06 PM

Whoa! Just went to TVFool and used their new app which shows topography. When I enter my street addy they have me deep in the valley when I'm actually on top of the highest hill around.

Result is I go from 2 edge to 40db nm!

Think I'll toodle on down to Ratshack and pick up something returnable to take a gander at OTA!

jtm

DieterW

06-29-09, 10:08 PM

with the SS-3000, which channels are unstable and which ones you can not receive at all?

Real/Virtual channels:
21/36, 33/24, 43/42 all come in perfect 99.9% of the time only notice a skip every few days.

22/18 is good most of the time; notice maybe a skip or two each day.

7/7 is good on some days, and others (seemingly same weather) have severe dropouts.

49/54 is pretty bad most days, with a skip every 10 seconds or so.

The SS-3000 is indoors about 7' up, with it pointing towards the towers, but passing "through" the house next door (Line Of Site points through the next door neighbor's home). I plan on putting the new antenna in the attic at the west-most end of my house, so it should hopefully almost have direct LOS to the towers, at least close-by (there are homes in the way at the end of the street). I have a 1-story home, and I estimate the antenna will be about 12 feet over ground level.

Thanks for the great links to lightning protection. I haven't visited this forum much, and it's very active, so searches had not helped me much (and the 300++pages on a lot of the discussions is a bit overwhelming!).

Oh, and the SS-3000 is VERY sensitive to position in my case; moving/rotating it 1/4" can totally change everything. This was the best I could manage.

Roof is composite/fiberglass shingles. No reflective foil/insulation.

Thanks again!

arxaw

06-30-09, 12:57 PM

300ohm

06-30-09, 06:52 PM

Whoa! Just went to TVFool and used their new app which shows topography. When I enter my street addy they have me deep in the valley when I'm actually on top of the highest hill around.
Result is I go from 2 edge to 40db nm!

Probably not completely de-bugged yet. Ive also seen some weird results from Canadians who enter in logitude/latitude. Seems some are supposed to get better reception when the antenna is on the ground vs at 25ft, heh.

Jim Miller

06-30-09, 07:12 PM

Both the interactive and old version show 2edge and I always thought that was strange since we are so high up. But the old version didn't show the actual location on a map with any detail.

The new version shows me down in a valley which explains the 2edge designation. Coming up to where we actually are is a 200ft rise and now shows LOS which is actually what I expect.

I don't have my GPS available until this weekend and when I get it I'll plug in the actual coordinates and see what results from that.

I just did a scan with no antenna at all and got hits on 6 out of 7 stations that I would expect to see. Not enough signal strength to get a picture however.

jtm

engage

06-30-09, 08:04 PM

Hello to the forum. I would like to fix this problem. The cabin is in northern Minnesota with transmitters 30 to 50 miles away. I know I'll need an antenna, a rotor and probably a pre amp but I don't know which ones. I've been lurking for a while and I bow down to the vast resevoir of knowledge that frequents this forum. The Cabin sits on top of a bluff so if I put the antenna on the roof I should get line of sight if an eighty foot Norway doesn't get in the way. Here is the Lat 46.75 Lon -93.27 I don't think I can post links yet. Thanks, Tom

engage

06-30-09, 08:10 PM

My forth post whoo hoo. maybe the links will work for TV fool data http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d618a704fb1039e

EscapeVelocity

06-30-09, 08:24 PM

Try a paper clip antenna Jim, till you get something better. Just unfold and stick in the 75 ohm input.

Jim Miller

06-30-09, 08:44 PM

I found pair of rabbit ears and hooked them up and got all but the RF11 and RF13 station. The rabbit ears are poorly positioned and the TV and stereo gear are between them and the desired sigs.

I'll rearrange tomorrow and I'm pretty sure all will be satisfactory.

tnx
jim

arxaw

06-30-09, 10:54 PM

Extend the rabbit ears 13" each and lay them down as horizontally as possible.

rabbit73

06-30-09, 11:20 PM

My forth post whoo hoo. maybe the links will work for TV fool data http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d618a704fb1039e

Welcome to the forum Tom.

Your signals at the cabin are very weak. You will need the very best UHF/VHF-hi combo antenna or better yet, separate high-gain UHF and VHF-hi antennas with a good preamp, mounted in-the-clear, aimed at 87 degrees, and as high up as you can manage.

Sometimes, when the terrain between the transmitter and the receiving antenna affects the signal, higher is not always better. Read about Peter Putman's experiments at his brother's cabin in Vermont:

Back in May of 2007, I wired up my brother’s house in a remote corner of southwestern Vermont to receive UHF terrestrial digital TV broadcasts from Albany, NY

The location was challenging because the house sits on the steep side of a narrow valley, with its view towards the southwest and the 54 mile-distant Helderberg Mountain TV transmitters completely blocked by a hill that is 100 to 200 feet taller and less than ½ mile away.
Nevertheless, I was able to successfully pull in four strong UHF DTV channels by exploiting a signal propagation phenomenon known as “knife edge refraction,” wherein radio and TV signals on VHF and UHF frequencies are actually bent downwards as they pass over the edge of hills and mountains, providing better-than-expected reception in their shadows.
http://www.hdtvexpert.com/pages_c/DTVtransitionRevisited.html

engage

07-01-09, 04:56 PM

Thanks for the reply Rabbit73. Before the switch I got four stations reliably with the roof antenna. I am assuming they were all from the same Duluth antenna farm. I think I have an unobstucted path to that farm.

Tom

Jim Miller

07-01-09, 06:21 PM

Just a followup: repositioned the rabbit ears and I now get a solid signal on all 7 stations.

For anyone living in a hilly terrain make sure to check out the new TVFool application and make sure that your location is properly placed.

For us there was the difference between 2Edge and LOS and 40db of noise margin due to the 200ft altitude error!

I was previously planning to put a mongo Weingard in the attic instead of the rabbit ears that are now proving more than adequate.

jtm

Jim Miller

07-01-09, 07:57 PM

ctdish

07-01-09, 08:45 PM

Actually all TV xmitters send out a horizontal signal with a few adding a vertical component. The antennas all have a radiating component that is horizontal but it is often inside a vertical cylinder having a lot of the radiating sections stacked vertically.
John

Jim Miller

07-01-09, 08:54 PM

i'm having trouble picturing this. is there anything that might show this on the web somewhere?

tnx
jtm

nordloewelabs

07-01-09, 11:01 PM

i'm curious too. any good links explaining this?

mlmahon

07-02-09, 04:12 AM

i'm having trouble picturing this. is there anything that might show this on the web somewhere?

tnx
jtm

Here's a picture to help you 'picture this". This pic is of a VHF channel 4 'Batwing' transmitting antenna. Notice the horizontal grids on the batwing panels for horizontal polarization. Also notice the 6 vertically stacked batwing bays to increase antenna gain.

rbarbier

07-02-09, 09:03 AM

Ok...

It is "clear" that the Clearstream 5 in not working for the High VHF stations for me (I can get a lock some of the time but it is not very reliable). Do you think this antenna will work for me?

http://www.antennacraft.net/pdfs/Y5-7-13.pdf

Here is my TVfool info:

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=618a9878f09890

I already get great UHF reception with the Clearstream 4 and will keep that of course. I also plan on having the Y5-7-13 on my apartment balcony on the second floor. There will be a small wall in front of it (currently the C4 has the wall in front but I still get great reception). These antennas will be ran into the 7777.

Also, I notice Solidsignal is backordered on these. Where else can I locate one to buy?

Thanks.

Digital Rules

07-02-09, 09:47 AM

The Y5-7-13 is light years better for VHF-HI than any of the Clearstream spaceship antennas. Your reception should improve, but there are still no guarantees that it will be 100% reliable. Brief signal interruptions are more common with VHF; even with the best antenna.

You can do a google search to check availability for the antenna. It is definitely in short supply these days.

serndipity

07-02-09, 10:43 AM

Since TV transmitting antennas are all verticals and the local reception mode is LOS wouldn't a vertical orientation of a rabbit ear dipole be more appropriate to match the vertical polarization of the transmitted signal?jtm

While the transmitting tower is vertical (e.g. to achieve elevation for the actual antenna), the antenna design at the top emits a horizontal polarized signal.

MacariahAVS

07-02-09, 02:03 PM

Don F.

07-02-09, 09:32 PM

rbarbier

07-03-09, 12:32 AM

The Clearstream c4 did not deliver either... The FCC maybe interested in your experience... They got mine...

Clearstream C4 works great for all UHF stations in Los Angeles. I sent back the Clearstream C5 today because it did not work for the Hi VHF like it stated.

I'll see how the Y5-7-13 works when I get it.

Satcom15

07-03-09, 10:15 AM

Here's a picture to help you 'picture this". This pic is of a VHF channel 4 'Batwing' transmitting antenna. Notice the horizontal grids on the batwing panels for horizontal polarization. Also notice the 6 vertically stacked batwing bays to increase antenna gain.

Hi mlmahon,
Thanks for the picture and information. I'm curious about several things:

1. Do the vertically stacked 6 bays have the effect of "flattening" the radiation pattern in the vertical (i.e. squash the donut)? I'm presuming the antenna has an omnidirectional pattern in the horizontal plane. I don't see anything in the antennas that lead me to believe there is a directional pattern. Or, could they do that with phasing transmit signals to the various bays.

2. How are the antenna's fed? I don't see a feed point.

3. I've always wondered about the batwing antenna design itself, why? That is to say, why does the antenna have that shape. Is there a gain or side-lobe supression advantage? Is it some multiple of the frequency? Or, is it multifrequency (within a certain VHF or UHF bandwidth)?

4. Is that shape typically used on UHF and VHF frequencies? Looks kind of small for a VHF transmitter. Or, is there another type of antenna used?

BTW a related thread on OTA signal polarization is located here:

http://www.avsforum.com/avs-vb/showthread.php?p=16260443&posted=1#post16260443

Thanks in advance for your thoughts.
Cheers
Satcom

300ohm

07-03-09, 11:10 AM

The Y5-7-13 is light years better for VHF-HI than any of the Clearstream spaceship antennas.
And much better on the wallet, too.

300ohm

07-03-09, 11:21 AM

But, I think a omnidirectional might be better.
Why would you think that when most of your signals are SE ? Mounting the antenna outdoors higher than 25 ft is your best option. Even so, dont count on getting any of the stations with a negative NM. (If youre very lucky, you may occasionally get some of them) I would get the old CM4228, as then you should also get channel 8.

300ohm

07-03-09, 11:40 AM

1. Do the vertically stacked 6 bays have the effect of "flattening" the radiation pattern in the vertical (i.e. squash the donut)?
1) Yes, vertical stacking does that. http://www.kyes.com/antenna/stackluge.html
2) From that distance in the picture, its impossible to see the relatively small connection point, heh.
3) Well, the batwing shape itself is very structurally durable, an important consideration. It certainly isnt the only type antenna used however.

PCTools

07-03-09, 02:17 PM

Well, the CM 7778 is sold.

Wow, I will have to watch the site for more of these posts.

Just kinda tells you how much of a mark-up is really with those.

NTNgod

07-03-09, 03:11 PM

If anyone wants a Channel Master 7778 amplifier, it is listed on the Best Buy Employee site for $2.51.

Looks like an Ebay-style auction to me?

PCTools

07-03-09, 03:24 PM

No, I would forbid those kinda posts.

This is available for Best Buy Employees only.

Requires account activation thru corporate.

Looks like an Ebay-style auction to me?

holl_ands

07-03-09, 03:41 PM

FYI: DTV Transmit Antennas:
http://www.dielectric.com/broadcast/pdf/New%20Antenna%20Designs%20for%20DTV%20Implementation.pdf
SuperTurnstile consists of several vertically stacked Crossed Bowties.
Each Crossed Bowtie consists of a Left and Right Bowtie (elongated vertically more than usual)
which provide coverage North and South. A second Bowtie at right angles covers East and West.
Each Bowtie is fed at the center point, just like the usual 1-Bay Bowtie.

As more and more Batwings are vertically stacked, the antenna pattern gets narrower
and narrower with respect to ELEVATION, while remaining omnidirectional in AZIMUTH:
http://www.dielectric.com/broadcast/brochures/TF-batwing.pdf

Transmit Antennas may use something resembling a DB-2 (with reflector)
or a simple dipole with reflector, wrapping 3 or 4 around the mast.
Multiples of these are vertically stacked to achieve the required Gain:
http://www.sitel.it/CATALOGO%20KATHREIN.pdf
At UHF, slot radiators are fairly common....a metal cylinder with holes.

Elliptically or Circularly polarized transmitters generate both Horizontal and Vertically polarized
signals, usually accomplished by two separate or intermingled stacked arrays, where each
vertically polarized element is physically rotated 90-degrees.

Circular polarization can come from Crossed Arrows....or Helical Elements (these are for FM):
http://photos.imageevent.com/holl_ands/ces2008//P10301401.JPG
http://photos.imageevent.com/holl_ands/ces2008//2006NAB%20Dielectric%20Quadrapole%20Antenna.jpg
http://photos.imageevent.com/holl_ands/ces2008//P10301371.JPG
[These hi-rez images are somewhat under 1 MB each.]

AntAltMike

07-03-09, 03:58 PM

Well, the CM 7778 is sold...

Just curious, how much did it sell for?

Just kinda tells you how much of a mark-up is really with those.

Not really. There are enough internet resellers for that product that the internet prices would be much lower than they are now if the opening bid price was anywhere near the wholesale price for that item.

I think the "Buy it Now" price of nearly $60 gives a better idea of what the seller expected the auction to fetch. Was it a closeout, or an open box item?

iowegian3

07-03-09, 04:08 PM

We finally dumped Dish Network as our 18mo subscription is finally over! I hated the quality of the signal and esp the costs. So am making a jump to OTA. But, in doing so I am so thoroughly confused about which is the best antenna to get for my area and even then, it all becomes so subjective.

I've come down to this and you are all welcome to assail me or give me a pat on the head. It looks like the 91xg may be the antenna of choice for my specific needs. But, I think a omnidirectional might be better. I've seen the Winegard 8200 and similar to be promising and of course the Channel Master 4228. So many variables, too many subjective possibilities I am hopelessly at a loss as to which antenna is best for my situation. I know I have to just jump in and try it out but sure would like to save some money and perhaps gets some good advice from you people before I do make the plunge.

I've got a two story brick with a window (in attic about 25') facing east (and west) ends but can set the antenna on an angle to face SE where most of the signals seem to reside. Tulsa is 60 miles as the crow flies. I've got OKC @ 100mi sw and Wichita another 100 miles NW. My question: Which is the better antenna to use for my particular circumstance?

Here are the tvfool specs:
tvfool.com/?option=com_wrapper&Itemid=29&q=id%3daa05f7981649ee

I look forward to your info and help. Thank you in advance..
Mac

Concentrate on Tulsa. Wichita & OKC are too far away to be reliable.

Try mounting in the attic, you may get lucky pointing through the roof. But I'd be prepared to mount on the roof at 60 miles out. Cable: RG6 or better. You may need a pre-amp mounted at the antenna. If splitting the antenna signal to two or more sets, use a distribution amp.

For a combo VHF-UHF solution, I'd try the Winegard HD7698P (http://winegard.com/kbase/upload/HD7698P.pdf) This would be the simplest solution IMO. You could use other combo V-U antennas. Remember that 2 and 6 are now on UHF, so don't bother with the old monsters with 7 foot long elements.

You might save some money by using separate VHF and UHF antennas, and you could get extra gain as well. Look at the AntennaCraft 10 element HI-VHF antenna (http://www.solidsignal.com/prod_display.asp?PROD=Y10-7-13) and the UHF antenna you mentioned above AntennasDirect 91XG (http://www.solidsignal.com/prod_display.asp?PROD=AD-91XG) Be sure to mount the two antennas at least 5 feet apart on the mast; too close and the signal will suffer.

Being Iowegian, I'm biased toward the Winegard and Antennacraft products, both based in Burlington. Especially Winegard, good antennas plus support:Winegard forums (http://www.winegard.com/phpbb3/)

PCTools

07-03-09, 04:10 PM

PM'd.

I am thinking about picking some the RG6 cable they have.

Just curious, how much did it sell for?

holl_ands

07-03-09, 06:42 PM

More Hi-VHF Antennas Analyzed...and Tested:

I analyzed and found "optimum" sizes for Hi-VHF Folded Dipole, Square Loop and Circular Loops:
http://imageevent.com/holl_ands/yagis

Surprise!!! Folded Dipole (1/2-in Pipe) received CH7, 9, 11 and 13 from Mt Wilson (70-miles in L.A.):
http://imageevent.com/holl_ands/smart
It beat out the DX Antennas DTA-5000 and RCA ANT2000 Smart Antennas...but winner was YA-1713.

In the attic (with lots of metal in the way) the big YA-1713 and even bigger Stacked Zig-Zag LPA
could only receive CH7 and CH9, but we're still searching for better locations...after it cools off some...
Local CH12 (only 2.7-miles away) causes adjacent channel interference to CH11 and CH13,
so we rotate antenna while watching/listening to CH12 to null it out....this isn't an easy process:
http://imageevent.com/holl_ands/zigzaglpa/zigzagnoboom

BTW: CM4228 UHF 8-Bay, by itself, only received CH9 prior to adding VHF antenna. Although we
didn't try to null out CH12 prior to making the upgrade, I doubt it would get CH7, CH11 or CH13....

arxaw

07-03-09, 06:51 PM

A friend was going to get a CM 4228HD, but I talked him out of it after someone else I know bought one and had to make a lot of modifications to it before it would work.

So now, he is considering an Antennacraft U8000 8bay (http://www.antennacraft.net/48Bay.html), which I've never seen. Is anyone here familiar with it or using one? Does anyone know if it has any high VHF gain?

300ohm

07-03-09, 07:04 PM

So now, he is considering an Antennacraft U8000 8bay, which I've never seen. Is anyone here familiar with it or using one? Does anyone know if it has any high VHF gain?
Because the reflectors on that horizontal double bay arent connected, probably no vhf-hi gain at all. But you could put a piece of 36 X 36 inch or so, 2 X 4 inch mesh on those reflectors and then get some vhf-hi gain on it. (or some 36 inch rods on the reflector) Still would be cheaper than the CM4228HD.

Satcom15

07-03-09, 07:39 PM

holl_ands,
Thanks for the information. I did not realize the batwing antennas are so large. I was deceived by the images I guess, there was no sense of scale. Looking at the product brochure and the dimensions, they are pretty sizable and heavy. Also, I'm wondering about feedline. One brochure referenced 1 5/8 in coax. Sounds like Andrew LDF7-50 or equivalent. I've done a fair amount of work with LDF5-50 (7/8 in diam) and a little bit with LDF12-50 (2-1/4 in diam). Working with it in a very cold climate is not particularly pleasant. :D

Pretty cool
satcom

arxaw

07-03-09, 07:50 PM

Because the reflectors on that horizontal double bay arent connected, probably no vhf-hi gain at all. But you could put a piece of 36 X 36 inch or so, 2 X 4 inch mesh on those reflectors and then get some vhf-hi gain on it. (or some 36 inch rods on the reflector) Still would be cheaper than the CM4228HD.And would probably work a helluva lot better than the 4228HD. Too bad ChannelMaster took a perfectly good design and ruined it.

cgulliver

07-04-09, 09:16 AM

I returned the Omnidirectional (15-1634) antenna to RS and grabbed a CM3016, CM4220M and a VHF/UHF combiner. What a dramatic improvement. Everything is 90%+ except for ION (14) which is 65-70%. Is ION any good?

RS tried to sell me one of these and I took a pass... http://www.radioshack.com/product/index.jsp?productId=2253765

This setup is not as aesthetically pleasing as the omni but it works...

http://i44.tinypic.com/9jd8vt.jpg

Digital Rules

07-04-09, 10:02 AM

This setup is not as aesthetically pleasing as the omni but it works...If you want something that is more aesthetically pleasing for not a lot of money, replace the CM 3016 with the Antennacraft Y5-7-13 Hi-band.($23.00 plus shipping) Put the 4220 at the top of the mast, and the Y5-7-13 3.5' below it. This may help you with ION 14 also, because your present antennas are too close to each other.

RS tried to sell me one of these and I took a pass... http://www.radioshack.com/product/index.jsp?productId=2253765Good move. Unless all your stations are UHF, it's pretty much useless.

arxaw

07-04-09, 10:40 AM

Something else you can do to help hide an antenna if there are trees behind it (when viewed from the street):
Paint the antenna and mast with Krylon ultra-flat camo paint. Olive gray/green color works well.

Below is an antenna painted with camo paint. There is a 4221 4-bay screen antenna on top and a VHF antenna near the bottom.
http://i40.tinypic.com/2hqwd1k.jpg

Here's a view from the street:
http://i40.tinypic.com/2eatlw4.jpg

JimP

07-04-09, 10:45 AM

I did something similar to a satellite dish.

PCTools

07-04-09, 11:18 AM

It is stealth technology.

I wonder if you take a performance hit with the paint?

JimP

07-04-09, 11:52 AM

It is stealth technology.

I wonder if you take a performance hit with the paint?

Probably, but not as bad as having to deal with neighbors.

arxaw

07-04-09, 12:50 PM

It is stealth technology.
:)

I wonder if you take a performance hit with the paint?No.

You can get Krylon ultra flat camo paint (http://www.krylon.com/products/camouflage_paint_with_fusion_technology/) at walmart, etc. or online.

Satcom15

07-04-09, 08:40 PM

Probably, but not as bad as having to deal with neighbors.

Honestly, don't people have other things to worry about? These are probably the same type of people that insist on shake shingle roofs in high wildfire risk areas for "aesthetic reasons" :D

Just reminder and for folks that might not know, HOA CC&Rs can not ban installation of antennas and the small direct to home satellite antennas per FCC rules. You are free to install outside antennas (with a few limitations). See the FCC website for details. Here are a couple of links:

www.fcc.gov/cgb/consumerfacts/consumerdish
www.fcc.gov/mb/facts/otard

Cheers

arxaw

07-05-09, 08:48 AM

Satcom15, I agree.
Anyone who would bitch about something as hard to see as the antenna combo in the above pictures needs to get a life.

JimP

07-05-09, 09:07 AM

....but someone's going to complain about "camo antenna" in big letters on the front of the house. :)

Satcom15

07-05-09, 07:48 PM

....but someone's going to complain about "camo antenna" in big letters on the front of the house. :)

Which begs the question, given FCC rules that specifically allow outside antennas (with some limitations - mainly related to height), why even worry about "camo"? Let 'em gripe -there's nothing they can do legally as long you comply with FCC regs. This is after all the 21st century with wireless technology all over the place. Wonder how many of the "gripers" use WLAN or cell phones? How do they think signals reach them? Why through an antenna of course. Technophobes! Sheesh. Personally, I find external antennas cool and am always on the lookout for "aluminum forests". Now if we could just get relief from CC&Rs for ham radio antennas ... :D but alas, current circumstances dictate Apartment living :( for now! :D

Cheers

cgorra

07-05-09, 08:25 PM

By the way, Funke has replaced the PDP-1922 with a new VHF high-band yagi called the PSIP-922u: it is only about 85 inches long, but claims better than 13db gain above channel 7. I am getting a sample soon, and will advise as to it's quality. It uses a large rear reflector that make it look a lot like a HUGE Winegard HD-9032, but I hear that it KILLS!

arxaw

07-05-09, 10:52 PM

Which begs the question, given FCC rules that specifically allow outside antennas (with some limitations - mainly related to height), why even worry about "camo"? I camo-painted my antenna because I wanted to, not to please anyone else. And there was no H/POA to deal with.

JimP

07-05-09, 10:59 PM

Is it generally understood that a good high VHF antenna is the horizontal yagi design?

Satcom15

07-06-09, 01:50 AM

I camo-painted my antenna because I wanted to, not to please anyone else. And there was no H/POA to deal with.

You are so lucky arxaw! I live in the land of CC&Rs - Colorado. You can barely breathe without worry of generating a violation. :eek: And finding a neighborhood without them? Good luck. So much for Rocky Mountain High. :D

ProjectSHO89

07-06-09, 07:02 AM

Is it generally understood that a good high VHF antenna is the horizontal yagi design?

That has been the conventional wisdom for a long time. By making it longer (adding more elements and length), it's performance can be increased.

JimP

07-06-09, 09:52 AM

That has been the conventional wisdom for a long time. By making it longer (adding more elements and length), it's performance can be increased.

That's what I was seeing when comparing UHF only antennas versus VHF only.

UHF seem to be vertical designs while VHF appear to be horizontal.

So when an antenna such as the 4228 picks up high VHF (which mine doesn't) is that mostly luck?

nybbler

07-06-09, 10:00 AM

That's what I was seeing when comparing UHF only antennas versus VHF only.

UHF seem to be vertical designs while VHF appear to be horizontal.

This is true, but my guess is it's mostly for mechanical reasons rather than electrical. And there are many exceptions on the UHF side -- the Antennacraft 91XG and the Radio Shack U-75, for instance. You can build an antenna just like the 4228 only scaled for VHF frequencies. But it will be very large and very heavy, and the 4228 is already large and heavy as antennas go.

axolotls

07-06-09, 12:32 PM

I am a NOOB.

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d497b1689d99e5f

Here's my report ^

Looks like the majority of the stations I want are the ones in the SW quadrant and are UHF.

Which antenna should I get? (I see 4228 might work). Even though they are 30 miles away, there are quite a few hills in the way. If more power = better than fine. Chimney mount is the only logical place and it's probably 30' high. Windy area.

Thanks!

TV Trey

07-06-09, 01:04 PM

Is it generally understood that a good high VHF antenna is the horizontal yagi design?

That is one. The Log-Periodic and Conical Array are two others to consider. All should be mounted horizontally, as i know of no TV stations that use vertical only polarization.

arxaw

07-06-09, 01:12 PM

axolotls,
The new chinese made ChannelMaster "4228HD (http://www.hdtvprimer.com/ANTENNAS/TemporaryPage.html)" is crap. Avoid it unless you want to modify it to make it a decent antenna.

By entering your specific address at TVFool, the results will be much more accurate. The results page will not display your address.

axolotls

07-06-09, 01:41 PM

bhlonewolf

07-06-09, 04:38 PM

[QUOTE=arxaw;16777814]axolotls,
The new chinese made ChannelMaster "4228HD (http://www.hdtvprimer.com/ANTENNAS/TemporaryPage.html)" is crap. Avoid it unless you want to modify it to make it a decent antenna.

By entering your specific address at TVFool, the results will be much more accurate. The results page will not display your address.[/QUOTE

Thanks. The results came out the same. I am only really looking for a UHF antenna. Glad to know the 4228HD is crap, I almost bit the bullet.

I own one of the new CM4228. After the fact and in reading many reviews, it seems the older model is a bit better, but I have to say I'm quite happy with its performance. I'm pulling in all the stations I need to (incl VHF HI), some from quite far away (70 miles), and it's in my attic.

I can't say whether it's better or worse than something else, but saying "it's crap" isn't that useful of a statement.

300ohm

07-06-09, 06:39 PM

Paint the antenna and mast with Krylon ultra-flat camo paint. Olive gray/green color works well.
Good job, and the stuff lasts well too. Ive used it on a small boat, after picking up a dozen cans of it at Lowes on clearance for 50 cents each, heh.

Without trees in the background, I find flat black works well for me. The paint does lower the velocity factor of the elements, but not enough to make a noticible difference. I dont like to paint uhf elements, but only the reflectors and directors.

I never used a light powder blue. To me, it would look too effeminate if spotted, heh.

arxaw

07-06-09, 07:02 PM

I own one of the new CM4228. After the fact and in reading many reviews, it seems the older model is a bit better, but I have to say I'm quite happy with its performance. I'm pulling in all the stations I need to (incl VHF HI), some from quite far away (70 miles), and it's in my attic.

I can't say whether it's better or worse than something else, but saying "it's crap" isn't that useful of a statement.Glad the new 4228 worked for you. It does work in some cases.

I based my "crap" statement not only on the review of it by hdtvprimer (http://www.hdtvprimer.com/ANTENNAS/TemporaryPage.html) (they called it and the new DB8 both "wrecks"), but also based on people in my area who've tried to use one.

One person replaced his previous CM4228 with the new chinese one, after a tree limb destroyed the old antenna during an ice storm last winter. He lost about half the channels he was getting, and returned it for a refund. Another guy I know bought one, but had to make several modifications (http://i32.tinypic.com/30kue82.jpg) to it, to increase the gain to a usable level. After his modifications, it worked quite well. But you shouldn't have to re-engineer a brand new antenna to make it work right.

axolotls

07-06-09, 07:18 PM

arxaw

07-06-09, 08:21 PM

Yes. It is fairly directional.
http://i25.tinypic.com/3481svp.jpg

There are chimney mounts available, which should withstand a pretty good wind.

300ohm

07-06-09, 08:36 PM

based my "crap" statement not only on the review of it by hdtvprimer (they called it and the new DB8 both "wrecks"), but also based on people in my area who've tried to use one.

"Designed by a clown" I believe is the phrase he used, heh.

Of course the antenna still works, but so does the YouTube coat hanger antenna. The point is, you should expect a little more from your hard earned money. I do, darn it. And if more dont complain about shoddy crap, the more we will get. Thats unfortunately a fact of life !

dvansowhat

07-06-09, 10:36 PM

Thanks again arxaw.

Still not being up on this stuff. The HD7697P you recommended...

Are these what they call directional? Do you point the 'spear' part where the signals are? In my case SW.

And, are there any special chimney mounts and masts for a semi-windy area. On some rare occasions short bursts of 55+ (the yard waste containers fly down the block).

Cheers

Ax I have the 7698 and I pick up stations at 43 mi. I put one up for my father and he is 63 mi. and picks up stations. None of these are amplified and the results have been very good. Mine has taken wind bursts of over 60mph and no problem. I also have a chimney mount. And yes it is directional so should work on your SW quadrant. Be forewarned that setting this antenna up requires two people to put together and you will have to be carefull mounting the two booms together. Also if you get it make sure you check the balun that is has not been damaged in shipment, spade lugs. Setting the phase lines are pretty simple once you figure it out. Take your time.

axolotls

07-06-09, 11:45 PM

Thanks for that info. Getting to the chimney is a hairy task (think multiple pitches of roof to transverse). Looking at the weight it seems they are fairly light (10lbs).I'll start comparing pricesinthe 769x series and actually see if what obstructions are in the way (only ones would be multiple hills)

marchioa

07-07-09, 12:06 AM

I live fairly close to my local transmitters and I am having trouble reliably getting signal on one channel. My info is here:

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d497be9079baae2

I only care about the "green" stations to the south. Most are ~3 miles and the one I have trouble with is KRMA-DT at 6.8 miles. I am using a small indoor antenna similar to the Philips Silver Sensor. I have moved it outdoors and pointed it at the transmitters; still KRMA-DT comes in around 50% signal/50% quality +/-10% on my HDHomerun. The 3 mile stations are at 100%/100%.

So, the question is what is the best next step to get KRMA-DT reliably?

Thanks

systems2000

07-07-09, 12:35 AM

And, are there any special chimney mounts and masts for a semi-windy area. On some rare occasions short bursts of 55+ (the yard waste containers fly down the block).
Three different points I'd like to make.

1) Don't exceed 3-5' of pole (above last mount), when using inexpensive antenna poles.

2) Use heavy gauge antenna pole or galvanized pipe up to a maximum of 10'.

3) It never hurst to overkill the number of chimney straps (more than two).

Rick313

07-07-09, 12:40 AM

So, the question is what is the best next step to get KRMA-DT reliably?

If you're happy with your reception of the other stations, I would say just be patient for now. Many people in the Denver area are unable to receive KRMA-DT because the station is currently operating at significantly reduced power from a less than ideal antenna location. They are in the process of installing a new antenna at a higher location and expect to be up at full power with their new antenna in August. You should not have any problem receiving them once their new equipment is operational.

Tower Guy

07-07-09, 07:18 AM

So, the question is what is the best next step to get KRMA-DT reliably?

You have quite a challenge. KTVD on channel 19 is 12 db stronger than KRMA on channel 18. (assuming that KRMA is actually running the power that is indicated on tvfool.)

What happens to the relative signal strength if the antenna height on tvfool is raised?

A preamplified antenna could be a part of the problem.

arxaw

07-07-09, 09:32 AM

dvansowhat,
I helped a friend install a 7694 (http://www.solidsignal.com/prod_display.asp?prod=HD7694P), the smallest one of the series. He's getting stations from up to ~50 miles away. The coax is split to two TVs and there is no preamp. Good elevation helps, of course, purely anecdotal results and individual results will vary. But I do think Winegard may actually be a bit conservative in their mileage ratings of the HD769 series.

The 7694 is fairly simple to assemble and can be installed on a J-Mount (http://www.solidsignal.com/prod_display.asp?prod=DS3000), but a taller mast may be preferable.

johnpost

07-07-09, 09:43 AM

some thoughts on chimney mounts: use with care. i don't have a lot of experience with chimney mounts or chimneys but some thoughts.

with a 'fake' chimney on a modern house, a metal chimney pipe often supported by a wood surround. it is best not to use strap around the chimney but bolt the mounting brackets into the wood.

with masonry chimneys they need to be in real good condition. they are intended to last decades are made strong enough to do so and may do so. depending on the age of chimney, its materials and construction, your local conditions for weather and what has happened to your chimney then it may or may not be in good condition. it is good that masonry be sealed and resealed if needed. chimneys are very exposed and take more of a beating than the rest of your house. water that gets into the masonry can cause deterioration, especially if you get freezing temperatures. mortar damage is not always easily seen from the ground with the naked eye. repair the chimney with repointing/tuckpointing if needed to have it be in very good condition before putting an antenna on it.

also if the chimney is in use it will cause the antenna to deteriorate a lot faster than if mounted elsewhere.

money__shot

07-07-09, 10:57 AM

Good day experts :)
I was wondering if someone could point me in the right direction.
I want to get an antenna but I am faced with MANY options.
I live here
hxxp://maps.google.ca/maps?f=q&source=s_q&hl=en&geocode=&q=k0g+1n0&sll=44.889673,-75.730627&sspn=0.013454,0.032938&ie=UTF8&ll=44.731126,-75.679321&spn=1.726799,4.216003&z=9

Here is what tvfool has to say.
hxxp://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d497b9c5bb94a63
I think ABC 7.1 FOX 7.2 is vhf, mabey more.
Would a CM3671 bring in all these channels?
Thanks a bunch

forgot to say i already have a 50 foot tower on my house...

systems2000

07-07-09, 11:05 AM

This will help money_shot

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d497b9c5bb94a63

What stations are you looking to acquire?

money__shot

07-07-09, 11:10 AM

thats the same tvfool page i posted :confused:

I want ALL of em (insert evil laugh here)

arxaw

07-07-09, 11:23 AM

You'll also need a preamp and rotor, to get the stations TVFool shows in pink (post transition selection). You may not get any stations below the pink ones in the TVFool list, at least not reliably.

The 3671 is for channels 2 thru 69. I don't see any lowband VHF channels (2 thru 6) in your list, so the added weight & size of the wide elements on the 3671 for those low VHF channels would be of little use, except for FM radio.

Unless you know of lowband channels that are not listed, or will be added later, you might want to consider some of the new smaller lighter antennas designed for channels 7 thru 69.

kedirekin

07-07-09, 11:23 AM

With only two posts, you weren't allowed to insert links. Systems2000 converted your TV fool report to a link for the convenience of other members.

marchioa

07-07-09, 11:44 AM

If you're happy with your reception of the other stations, I would say just be patient for now. Many people in the Denver area are unable to receive KRMA-DT because the station is currently operating at significantly reduced power from a less than ideal antenna location. They are in the process of installing a new antenna at a higher location and expect to be up at full power with their new antenna in August. You should not have any problem receiving them once their new equipment is operational.

Thanks for that information. Everything else works fine with the antenna outside I get 100% signal/quality on most other stations. I can't complain about that. The further away stations are not worth the trouble for me. I'll just sit and wait for them to improve their transmitter.

money__shot

07-07-09, 11:51 AM

thanks for your quick replies
I currently have a coat hanger antenna i made off youtube up there.
here is what im getting off that antenna

4-1 CBOT CBC GET IT
-------------------------------------
7-1 WWNY-dt CBS DONT GET IT
-------------------------------------
7-2 WNYF-dt FOX DONT GET IT
-------------------------------------
9-1 CBOFT CBC french GET IT
-------------------------------------
16-1 WNPI (SD) GET IT same as 18-1
16-2 WNPI (think) GET IT same as 18-2
16-3 WNPI (HD) GET IT same as 18-3
-------------------------------------
18-1 WNPI (SD) GET IT
18-2 WNPI (think) GET IT
18-3 WNPI (HD) GET IT
-------------------------------------
20-1 SUN TV(HD) GET IT
20-2 SUN TV(SD) GET IT
-------------------------------------
27-1 OMNI 1 GET IT
27-2 OMNI 1 GET IT
-------------------------------------
50-1 WWTI-dt ABC GET IT (low signal on bad days)
50-2 WWTI-2 The CW GET IT (low signal on bad days)
-------------------------------------
66-1 OMNI 2 GET IT

The coat hanger thing was temporary just to see if it was worthwhile investing in this from my location.

Jim Miller

07-07-09, 12:13 PM

i'll add that chimneys often begin failing due to the chimney cap failing. it is often mortar and poorly sealed or with seals that have deteriorated. once they fail the entire top of the chimney fails rapidly. this is seldom obvious from the ground and often difficult to assess unless you can actually get into a position to see the top of the chimney up close.

personally i'd never add an additional load to any chimney. furthermore the chimney output will rather rapidly corrode the metal antenna.

jtm

arxaw

07-07-09, 01:09 PM

I currently have a coat hanger antenna i made off youtube up there.
7-1 WWNY-dt CBS DONT GET IT
7-2 WNYF-dt FOX DONT GET IT

Channel 7 is VHF (chs 2 thru 13). The youtube antenna is for UHF (chs 14 thru 69) only. It will sometimes work for VHFs, but only if they're fairly strong at your location.

The actual channel numbers being used are shown in the REAL column on TVFool (http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d497b9c5bb94a63).

axolotls

07-08-09, 01:32 AM

johnpost

07-08-09, 10:18 AM

some thoughts on chimney mounts: use with care. i don't have a lot of experience with chimney mounts or chimneys but some thoughts.

with a 'fake' chimney on a modern house, a metal chimney pipe often supported by a wood surround. it is best not to use strap around the chimney but bolt the mounting brackets into the wood.

also if the chimney is in use it will cause the antenna to deteriorate a lot faster than if mounted elsewhere.

Goodpoint. It is wood surrounding a metal pipe. Need to check it out. Perhaps strapping and bolting, if possible?

the straps need to compress tight against something. most siding material will need to be deformed to become tight or it will likely compress over time and loosen the mounting.

with a wood surround you could put lag bolts into framing members on the inside. or mount through the sheeting with something like butterfly bolts. use the biggest bolts you can fit through the mounting brackets. good idea to put caulking into the hole after the butterfly gets in and under the bracket. also caulk top and front of bracket after tightened down.

Tower Guy

07-08-09, 01:10 PM

mount through the sheeting with something like butterfly bolts.

I'd be careful about fastening to anything other than studs to trusses. Some builders use cheap pressboard for walls.

I use a wall mount with lag bolts into a 2X6 that I fastened between the studs in the gable ends of the roof truss.

300ohm

07-08-09, 04:12 PM

Yeah, you definately want to go into a solid stud with lag bolts. Locate with a good stud finder if you dont have aluminum siding (or foil house wrap, like me, heh). Even then you have to watch out for knots and holes.

johnpost

07-08-09, 05:01 PM

with a wood surround you could put lag bolts into framing members on the inside. or mount through the sheeting with something like butterfly bolts. use the biggest bolts you can fit through the mounting brackets.

I'd be careful about fastening to anything other than studs to trusses. Some builders use cheap pressboard for walls.

I use a wall mount with lag bolts into a 2X6 that I fastened between the studs in the gable ends of the roof truss.

i agree that a wall mount is better than a chimney mount especially into an already existing fake chimney. also an active chimney will corrode an antenna and require more frequent maintenance and replacement.

for myself i would even do machine bolts or threaded rod through the 2x6 instead of lag bolts.