Hi guys, I'm brand new to the AVS Forums but I joined mainly due to this thread. I've had cable from about the age of 8 (30 now and a pricey digital cable package to go with it!), but fondly remember the old OTA days at my parents' house. I am getting into OTA myself after purchasing a 50" HDTV and wanting the best picture possible for the local channels. I also want to protect myself after the digital transition if I move to satellite (7 TVs and I'd want at most 4 satellite STBs, leaving three more TVs to cover).

Anyway, on to the meat of the post. I want to dabble in DXing later on if time/money permit, but for now I want to keep it simple. I've attached the TV Fool report for my exact coordinates post-transition while leaving the antenna height blank. Here's what I want:

1) Roof mounted antenna on my single story home.
2) The St. Louis stations located from 255-273 degrees.
3) I'd like to have WSIU Ch. 8.
4) I want to view these on my two main TVs for sure but also if possible on two more tvs. The longest cable run should be 75 feet at most, less for the two main tvs centered in the house on the main floor and the finished basement family room.

After studying this for about a week, I think some type of Channel Master UHF antenna should do the trick and hopefully allow me to pull in WSIU. I'll get WPXS no matter what I do. I know people say to get a little more antenna than I need. If I get a CM4228HD, would I also need/want a CM7777 pre-amp? Is a 4228HD overkill by itself? Not having had real world experience with OTA, I have no practical experience to guide me here. What do you think?
A Preamp is a very good idea given multiple drops and long cables.
CM-7777 is probably okay for now, with only one very strong station, which would be
attenuated by nulls in the CM-4228's antenna pattern.

You have stations coming in from three directions, so you probably are considering a rotator.
Since the CM-4228 has moderate Hi-VHF gain, you may not need a separate VHF antenna.

On the other hand, a dual VHF and UHF antenna solution should also work.
Point a VHF (e.g. W-G YA-1713, Antennacraft Y-10-7-13 or Y-5-7-13) towards Ch8
and (using "UVSJ" combiner) point CM-4228 towards the West (or rotator)....
nearby Ch21 should come in on the sidelobe....if multipath isn't too bad.

Even with high gain antennas and a Preamp, the "pink" stations will be difficult and
below that will be nearly impossible except during anomalous propagation conditions.

Gandolf007:
Your signals are even weaker, so the CM-7777 and CM-4228 are good choices.
If the Hi-VHF performance of the CM-4228 is inadequate, you may need to add
a Hi-VHF antenna (e.g. W-G YA-1713, Antennacraft Y-10-7-13 or Y-5-7-13).

However, pointed SE, you probably won't pick up stations towards NW other
than maybe Ch12. These are duplicate networks, so perhaps it's not a problem.
[CM-4228 has much lower F/B Ratio for Hi-VHF channels.]

It states:

Quote:
“75 percent or more of the over-the-air households have only set-top antennas.”

So perhaps, it does not even include attic antennas in the 75%.

It all depends on how they phrased the phone query. I would expect:
"Do you have a roof-top antenna?" would result in attic antennas being "indoors"...

Why choose the CM7777 all of the time? Why not choose the CM7778 when you are not in the deepest fringe area with a bad (low sensitivity) receiver? Is there something wrong with the CM7778? How come no one recommends the CM7778?

To me the gain looks just fine on the CM7778. It is more balanced than the CM7777. I ran some link budget calculations on my home system with the CM7778 and four room splits, and still came out with "a little" more gain then system loss (see post 8319). That even included deducting the noise figures of the preamp. Why would you want to overload the front end of your receiver with excess preamp gain? How would that benefit reception? Wouldn't it hurt reception at some point?

I think it would. I have seen selectivity and image rejection fall apart with excessive preamp gain into a receiver. The only case where a little extra helps is with a deaf receiver, but even then the selectivity and image rejection are at risk. So wouldn't it make sense to design your antenna system with just enough preamp gain to overcome feedline and splitter losses and not much more?

And lots of people have foil backed insulation in the walls, like me. It also seems some of the newer shingles have something like ground up steel wool in them. Anything but outdoors is a poor mounting location.


Yes, I forgot the old foil-backed insulation. I have that too! It keeps the A/C bills down in HOT Florida. Those cheapskate homes I saw go up around me had none of that. Wait till they get the electric bill. Ouch! :D

The only way any signal is getting into the lower part of this house is through the large glass doors and windows!:p

Is a 4228HD overkill by itself?

Yes. The beamwidth of the 4228 is 19 degrees on channel 40. Your UHF stations are spread out by 18 degrees. A 4221 is more appropriate.

To me the gain looks just fine on the CM7778. It is more balanced than the CM7777.

It has 3dB less UHF gain and 7dB less VHF gain than the 7777, 23dB and 16dB respectively. So it probably makes sense for someone with either a much better VHF than UHF antenna (although a bigger UHF antenna would make more sense), or powerful VHF stations with weak UHF stations, or in situation where terrain is a bigger problem than distance and most channels are received by a diffraction path.

On the other hand, most people considering the CM7777 are probably looking at stations down below -90dBm anyway. With the input power that low, the extra gain of the 7777 isn't going to hurt and might help. Even if it does turn out to overload the receiver... splitters are cheap.

A couple of years back this forum helped me select my roof antennas a Wineguard P-8800 8 bay and a 5 element CH 3 only for my PBS station (nasty of them to go to ch 3). I have 2 locations 30 deg apart (23 miles and 47 miles) and a comprimise setting gets all with mostly good reception (ch 3 and 18 from 47 miles have some problems). Per TVFOOL all stations are green. They are combined with a CM7777 with about 40' of cable.
There is a Radio Shack large combo antenna in the attic that I decided to run to another TV and found it was better than the roof two antennas. I also have cable which I plan to cancel when I receive my DVT PAL DVR (2 tuner HD DVR).
I ran the attic cable into the Comcast cable 4 way splitter and all TV's had an acceptable redception - equal to the combined antennas on the roof.
The attic location seems to be better - it is below wires on the poles in front of it.
Th roof antennas are closser to the wire elevation - possible reason? Or just luck that the attic location is better
Another thought - the CM7777 is too much for the roof. If so how do I combine them?
How about moving the CM7777 (set with one input) to the attic and use the RS antenna with over 100' cable and a four way splitter with more cable runs.
How about moving the roof antennas to the attic (if they fit) with the CM7777 also going to the 4 way splitter.
If the attic works why not use it? Moving the CM7777 will be my first (and easiest move).
Any thoughts.
Bernieoc

Hi guys, I'm brand new to the AVS Forums but I joined mainly due to this thread. I've had cable from about the age of 8 (30 now and a pricey digital cable package to go with it!), but fondly remember the old OTA days at my parents' house. I am getting into OTA myself after purchasing a 50" HDTV and wanting the best picture possible for the local channels. I also want to protect myself after the digital transition if I move to satellite (7 TVs and I'd want at most 4 satellite STBs, leaving three more TVs to cover).

Anyway, on to the meat of the post. I want to dabble in DXing later on if time/money permit, but for now I want to keep it simple. I've attached the TV Fool report for my exact coordinates post-transition while leaving the antenna height blank. Here's what I want:

1) Roof mounted antenna on my single story home.
2) The St. Louis stations located from 255-273 degrees.
3) I'd like to have WSIU Ch. 8.
4) I want to view these on my two main TVs for sure but also if possible on two more tvs. The longest cable run should be 75 feet at most, less for the two main tvs centered in the house on the main floor and the finished basement family room.

After studying this for about a week, I think some type of Channel Master UHF antenna should do the trick and hopefully allow me to pull in WSIU. I'll get WPXS no matter what I do. I know people say to get a little more antenna than I need. If I get a CM4228HD, would I also need/want a CM7777 pre-amp? Is a 4228HD overkill by itself? Not having had real world experience with OTA, I have no practical experience to guide me here. What do you think?

I think you should try just the 4228 first directed toward St. Louis. mounted at least 25' AGL were signal strength is stronger. If needed to get channel 8 a inexpensive AntennaCraft Y5-7-13 added to the mast combined with a UVSJ will do the trick. I've got a similar set up in my attic with a DIY 4bay DB4 with slightly stronger signal strengths being about 35 miles from transmitters. This is your plot with antennas at 25' see the difference:D.
Combined antennas to a distribution amp for multiple receivers. Pico makes fine amps for pro setups. http://yhst-18278607509093.stores.yahoo.net/products-distribution-active-component-amplifiers.html

http://www.tvfool.com/modeling/tmp/37c7b60d76/Radar-Digital2.png

A couple of years back this forum helped me select my roof antennas a Wineguard P-8800 8 bay and a 5 element CH 3 only for my PBS station (nasty of them to go to ch 3). I have 2 locations 30 deg apart (23 miles and 47 miles) and a comprimise setting gets all with mostly good reception (ch 3 and 18 from 47 miles have some problems). Per TVFOOL all stations are green. They are combined with a CM7777 with about 40' of cable.
There is a Radio Shack large combo antenna in the attic that I decided to run to another TV and found it was better than the roof two antennas. I also have cable which I plan to cancel when I receive my DVT PAL DVR (2 tuner HD DVR).
I ran the attic cable into the Comcast cable 4 way splitter and all TV's had an acceptable redception - equal to the combined antennas on the roof.
The attic location seems to be better - it is below wires on the poles in front of it.
Th roof antennas are closser to the wire elevation - possible reason? Or just luck that the attic location is better
Another thought - the CM7777 is too much for the roof. If so how do I combine them?
How about moving the CM7777 (set with one input) to the attic and use the RS antenna with over 100' cable and a four way splitter with more cable runs.
How about moving the roof antennas to the attic (if they fit) with the CM7777 also going to the 4 way splitter.
If the attic works why not use it? Moving the CM7777 will be my first (and easiest move).
Any thoughts.
Bernieoc


The first rule in antenna placement: Location location location!

Or was that realestate? :D

I have had similar experiences with all sorts of antennas. This is how I choose an antenna location; I take a portable receiver (with signal meter) and move the antenna up and down over all possible mounting locations. Sure enough...some spots are HOT and others are NOT. Locate the hot spots and mount there. Higher is not always better. On UHF a few inches can make a huge difference...VHF a few feet can do the same.

One time I put a 52 MHz (ham) ground plane antenna on my lawn as a temporary install until I could get it up on the roof. That location was HOT! I was talking 100+ miles simplex with 100W FM. No matter where I tried it on the roof, it was never as good. I never got that same range and repeaters were much weaker. I could tell more tales about weird antenna results, but this is not the forum for it. One thing I can say...high gain antennas are not always better. Verry narrow and compressed patterns on UHF can make reception go in and out when the wind blows. There is such a thing as "too much gain". One 6 dB low band antenna missed almost all 500 (and under) mile band openings but excelled on 1,000 + miles. People near me were talking to stations 300 - 500 miles that could not hear at all. I was talking better to long E skip. Why? It turns out the angle of radiation was too low (compressed) on the high gain antenna to do short skip. That is why looking at polar patterns and choosing the right antenna is better than thinking "bigger has to be better". ;)

You make a good point... would the HD7697P be a better choice than the 7698? (Note, I didn't plan on using a 4228 -- I know I need a good VHF antenna to pick up ch. 8, 11, and 13 from 67 miles away, and the Winegard 769x line looks like a good way to get that in one antenna.) I'm still leaning towards getting the stronger 7698, but am having trouble deciding on a preamp. I know the CM7777 is good but I'm worried about KBTX overloading it. Other options are the CM7778 and Winegard AP8700, 8780, and 8800.

I don't care about the stations from the NW, since they're all duplicates. If they come in, great, but he doesn't get them with rabbit ears now, so he wouldn't miss them.

to be honest, I would not use the cm7778 or the other "16/23" gain preamps in the suburbs. too much gain. I stick with the hdp269. a ham tends to want extra amp gain to try to squeek more signal. I favor using less amp gain and larger antennas for more gain...even a few sizes larger than typical.

the cm7778 electronics are in the same class as the cm 0068 preamp but in a cm7777 case. from what I understood, the cm 7777 and cm 7778 are not of the same class.

http://www.solidsignal.com/antennas/preamplifiers.asp

In general, use the hdp 269 amp in the suburbs less than 25 or so miles from towers and all other amps, 30 or so miles from towers. ultimate amp selection depends on the several variables encountered on site.

holl_and's preamp tool and process gets you in the ball park. Use it often..thanks

Not in the same class? What does that mean? :confused:

Looking at the chart in the link you posted, they got it wrong on the combining issue. That is how they classified them, and they are wrong. Solid Signal is not the best source for information. Both the CM7777 and CM7778 can use separate antennas for V/U, or combine them with a switch inside. This is a better source for information:

http://www.channelmasterintl.com/amplifiers.html

The noise figures are close and the CM7778 has plenty of gain where you need it. All that extra gain on VHF is not needed. 3 dB on UHF is pointless if you are already ahead +8 on the link budget. Remember...a preamp does not give you "antenna gain". They are not designed to increase range. They are designed to overcome line loss and preserve antenna gain. The antenna is where you really get meaningful gain. A good receiver is also a major factor. A little extra preamp gain can't hurt, but too much can.

This is your plot with antennas at 25' see the difference


That brings up the question, are the dB's, dBi from antenna gain and dBm from TVFool, equivalent ?

That brings up the question, are the dB's, dBi from antenna gain and dBm from TVFool, equivalent ?
Here's a good link to Field Intensity Unit comparisons and formulae:

http://www.softwright.com/faq/engineering/FIELD%20INTENSITY%20UNITS.html

FYI - I know what an amp does.

Well good for you. :rolleyes:

...you see what I mean now ??? The cm7777.7775 are better.

NO. :mad:

Not better, just different. 0.2 dB NF difference is nothing.

And I know how the ap8700, 8780, 4700,cm7778, cm0068,cm7777, etc. generally perform in the suburbs. I do not use the higher gain amps there unless the signals levels are below typical for that zone and require an amp with higher gain. It all depends on the unique variables of antenna gain, distribution losses, transmitter powers, the combination of channels in the market, loss due to geography and other external factors, inside install, etc. at the site.

Well woopie! :rolleyes:

The challenge then is how to compromise when you want to receive both local and distant channels in the suburban environment with high signal levels. The higher gain amps generally make things worse under those conditions.

That is what I was saying all along. You're not saying anything I don't already know, so why bother? Never mind...it's not that important. :cool:

Thanks for the link Stampeder.

From the site:

When a "field strength contour" is plotted and identified in dBm or microvolts (dBµV), it is important to know these values of frequency and antenna gain. The user must understand that such "contours" are only valid for one frequency and the particular receiving antenna gain used for the prediction. There is also a fixed loss in the receiving antenna transmission line - often assumed to be lossless.

So, that meant I needed to know what gain antenna TVFool was using as a measurement reference. TVFools new FAQs gave me what I was was looking for :

Antenna gain is the only quantity that should ever be ADDed to the NM value. Most antennas will specify their gain in dBd or simply dB, and this is the value that should be used. If an antenna's gain is specified in dBi units, then you need to subtract 2.15 in order to get the equivalent value in dBd units. If an antenna has a built-in amp, the extra gain from the amp SHOULD NOT be included as part of the antenna gain (this actually subtracts from the Noise Margin as we'll see next). Only the raw intrinsic gain of the physical antenna should be added to the Noise Margin.

Be aware that amps and pre-amps will actually cause you to lower your Noise Margin. No matter how much gain an amp or pre-amp claims, it will actually reduce your Noise Margin by the amount listed as the Noise Figure (NF) in its specs. High quality consumer-grade amps usually have a Noise Figure of around 2-3 dB. Lower quality amps or ones that do not specify a noise figure at all will probably have a Noise Figure of around 6-10 dB. This is true for both stand-alone amps as well as antennas with built-in amps. This Noise Margin degradation is caused by limited efficiency of the electronics at the input of the amp prior to the signal being boosted. The primary benefit of the amp is to overcome further NM degradation from "downstream" losses (e.g., long cable runs, splitters, tuners with poor sensitivity, etc.). In other words, you suffer the amp's Noise Figure degradation once, and can usually ignore most of the other losses that occur after it.

See attachment for the SolidSignal Preamp Table, where I added a column
with the Max Input (dBm) for best Spurious Free Dynamic Range (SFDR)...
that is, minimal desensitization on weak channels due to intermod products.

Don't forget to adjust www.tvfool.com receive signal level (dBm), to add
antenna gain (dBd) and take away losses PRIOR to Preamp (e.g Balun/Coax).

Additional explanatory info and a detailed Calculator (incl LOS) were posted 4 Nov:
http://www.avsforum.com/avs-vb/showpost.php?p=15005797&postcount=8148

Fol. explanation from TVFool is close, but seems somewhat misleading:
Antenna gain is the only quantity that should ever be ADDed to the NM value. Most antennas will specify their gain in dBd or simply dB, and this is the value that should be used. If an antenna's gain is specified in dBi units, then you need to subtract 2.15 in order to get the equivalent value in dBd units. If an antenna has a built-in amp, the extra gain from the amp SHOULD NOT be included as part of the antenna gain (this actually subtracts from the Noise Margin as we'll see next). Only the raw intrinsic gain of the physical antenna should be added to the Noise Margin.

Be aware that amps and pre-amps will actually cause you to lower your Noise Margin. No matter how much gain an amp or pre-amp claims, it will actually reduce your Noise Margin by the amount listed as the Noise Figure (NF) in its specs. High quality consumer-grade amps usually have a Noise Figure of around 2-3 dB. Lower quality amps or ones that do not specify a noise figure at all will probably have a Noise Figure of around 6-10 dB. This is true for both stand-alone amps as well as antennas with built-in amps. This Noise Margin degradation is caused by limited efficiency of the electronics at the input of the amp prior to the signal being boosted. The primary benefit of the amp is to overcome further NM degradation from "downstream" losses (e.g., long cable runs, splitters, tuners with poor sensitivity, etc.). In other words, you suffer the amp's Noise Figure degradation once, and can usually ignore most of the other losses that occur after it.
The idealized receive sensitivity (-91 dBm) is calculated from knowing that DTV
requires the signal to be at least 15 dB above the thermal noise floor (-106 dBm).
In real systems, the System Noise Figure measures degradation from this ideal.

For example, if a DTV Tuner with NF=7 is connected directly to a 75-ohm antenna
(no Balun), sensitivity would be -84 dBm (CECB converter box spec is -83 dBm).

Without a Preamp, overall System Noise Figure is the sum of the Balun Loss (typ. 1.5-3 dB),
Antenna-to-Tuner Coax/Splitter Losses plus the Tuner Noise Figure (typ. 7-14 dB).

On the other hand, with a Preamp the overall System Noise Figure is the sum of the Balun Loss
(typ. 1.5-3 dB), Antenna-to-Preamp Coax Loss (hopefully very small), the Preamp Noise Figure
(typ. 2.2-3+ dB) and the post-Preamp Losses AS REDUCED by the Gain of the Preamp
(only about 1-2 dB).

So a Preamp has the POTENTIAL to improve sensitivity by 10+ dB...but ONLY IF it is
operated within the SFDR "linear" region....

Whenever input signal levels exceed numbers given above, intermod products
will pop up at various frequencies, desensitizing certain channels...

What is considered a strong signal? Here is my TV Fool plot. http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dcc5a3b06f0 I would like to add a CM 7777 preamp, but now I am a bit worried about overloading the preamp or overloading the TV tuner. I am looking at the stations 90 degrees east and also at 312 and 326 degrees northwest. The stations to the northwest could definitely use the amplification, but I am now worried about the overload issue if I introduce the 7777 and amplify the stations from the east. I use a pair of 91XGs for UHF and a pair of Funke PSP.1922s for VHF, each band combined with jointennas, then the bands combined with a UHF/VHF diplexer. I am hoping to swap the diplexer for the 7777. Hollands???

Any thoughts? (by the way, I have plugged in to your other spreadsheets, but it is greek to me...)

Bill

EDIT!!!!!: OOPS! This link only shows the current DTV signals. I am working to get the POST TRANSITION signals. You will need to change the chart to POST TRANSITION DIGITAL ONLY to view what I am looking for! Sorry about the confusion.

Bill

Green signals are strong signals on the TV Fool plots. I would anticipate problems if you use a 7777 with the antenna(s) pointed to the East. The other directions are probably ok with the 7777, but you may want to consider a higher input pre-amp if you want to use it for all of the stations on your plot.

What is considered a strong signal? Here is my TV Fool plot. http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dcc5a3b06f0 I would like to add a CM 7777 preamp, but now I am a bit worried about overloading the preamp or overloading the TV tuner. I am looking at the stations 90 degrees east and also at 312 and 326 degrees northwest. The stations to the northwest could definitely use the amplification, but I am now worried about the overload issue if I introduce the 7777 and amplify the stations from the east. I use a pair of 91XGs for UHF and a pair of Funke PSP.1922s for VHF, each band combined with jointennas, then the bands combined with a UHF/VHF diplexer. I am hoping to swap the diplexer for the 7777. Hollands???

Any thoughts? (by the way, I have plugged in to your other spreadsheets, but it is greek to me...)

Bill

EDIT!!!!!: OOPS! This link only shows the current DTV signals. I am working to get the POST TRANSITION signals. You will need to change the chart to POST TRANSITION DIGITAL ONLY to view what I am looking for! Sorry about the confusion.

Bill

Bill, you should be fine using the CM 7777 with your setup. You are 37 miles from your nearest station. I'm using the 7777 with virtually the same setup you have (pair of Triax Unix 100s instead of the 91XGs, and a single Funke PSP 1922) and I'm 3 - 5.5 miles from my local TV and FM radio towers. I do have a few overload issues with some analog channels, but to date, no noticeable overload issues caused by the 7777 with local or distant digital channels.

I've attached a pic of my setup, which does include a single 91XG about 2.5 feet below the Triax stack and about 4 feet above the Funke 1922.

Steve

See attachment for the SolidSignal Preamp Table, where I added a column
with the Max Input (dBm) for best Spurious Free Dynamic Range (SFDR)...
that is, minimal desensitization on weak channels due to intermod products.

Don't forget to adjust www.tvfool.com receive signal level (dBm), to add
antenna gain (dBd) and take away losses PRIOR to Preamp (e.g Balun/Coax).

Additional explanatory info and a detailed Calculator (incl LOS) were posted 4 Nov:
http://www.avsforum.com/avs-vb/showpost.php?p=15005797&postcount=8148

Holl_ands, could you help me pick a pre-amp? My tvfool results are attached. I'm using an attic mounted DIY antenna (assume gain at ~10 db). The distribution will include 120 ft rg-6, one 2-way splitter, and two a/b switches. My two highest power signals average -35 dbm. If I add antenna gain to highest power signals (-35 + 10 = 25) and then subtract for balun and pre amp noise figure (-25-2-3 = -30), I have a max input of -30 dbm (not subtracting losses from attic mount). Based on your table, I should stay away from a Channel Master 7777 and look for a lower gain pre-amp such as the Winegard 8700 or HDP269, correct? Which would you recommend? Thanks!

Bill, you should be fine using the CM 7777 with your setup. You are 37 miles from your nearest station. I'm using the 7777 with virtually the same setup you have (pair of Triax Unix 100s instead of the 91XGs, and a single Funke PSP 1922) and I'm 3 - 5.5 miles from my local TV and FM radio towers. I do have a few overload issues with some analog channels, but to date, no noticeable overload issues caused by the 7777 with local or distant digital channels.

I've attached a pic of my setup, which does include a single 91XG about 2.5 feet below the Triax stack and about 4 feet above the Funke 1922.

Steve

Like your setup, why have the 91XG pointed the same direction as the pair?

On the other hand, most people considering the CM7777 are probably looking at stations down below -90dBm anyway. With the input power that low, the extra gain of the 7777 isn't going to hurt and might help. Even if it does turn out to overload the receiver... splitters are cheap.

I find on most receivers, if there are not stations stronger than -40dbm, a 7777 should not overload. Now if all your stations are that strong, it's a waste of money, I agree. I have stations from -40 to -70 on a 4221 and it works fine.

I find from playing with preamps on TV/FM and ham bands that what becomes more important is the noise floor of the amp, not the gain. The 7777 has the best noise floor on the market. It's noise floor is better than most receivers. Putting a 7777 in the path lowers the noise floor for the entire system to the noise floor of the amp, since the amp brings the signal level up so high, the noise floor in the receiver becomes moot in most cases.

Another comment I heard is hams think more gain is better. You can be sure this Pig/Ham thinks you put as much metal in the sky as you can. The antenna determines how much signal you capture. The amp can't make up for that in raw RF. But the amp lowers the noise floor of the system, making it seem to add "gain" to the system.

I would love to be able to buy an amp with the noise floor of a 7777 but half the gain. My worst case on my highest channel (36) on 100 ft of coax and a splinter is only about 6 to 8 db of loss. Even adding a 4 way for more receivers would only up that 3db, hence about 20 to 30 db of gain would work.

Like your setup, why have the 91XG pointed the same direction as the pair?

It's aimed in the same direction as I've been testing and experimenting between the single antenna and the stack. Several weeks ago I had a CM 4228 mounted below the Triax stack instead of the 91XG. Overall, I tend to prefer the 91XG over the CM 4228.

Steve

Never mind, didn't read the FAQ.

Overall, I tend to prefer the 91XG over the CM 4228.

Today. But come February, the CM4228 should be your choice.

Today. But come February, the CM4228 should be your choice.

Even after Feb. 17, the CM 4228 (now the 4228HD) still won't be my top choice. With a Winegard YA 1026 for low band VHF, a Funke PSP 1922 for high band VHF and a pair of Triax Unix 100 W/B antennas stacked, I'm ready for local and distant (DX) DTV stations.

Steve

bernieoc:
1. Outdoor signal strengths now and Post-Feb are very strong. Preamps will
generate intermods, desensitizing the DTV tuner. Which would explain why
the extra loss in the attic location works better.

This extra attic loss may lower signal levels enough to use the HDP-269 Preamp....
or the CM-7777 with extra input attenuation.
Try putting 3-10 dB of attenuation between the antenna and the Preamp, such as
one or two RF Splitters (4 dB each) or an (OUTDOOR!!!) RF Attenuator:
http://search.solidsignal.com/?site=com&q=attenuator&I1.x=0&I1.y=0

2. WBRA-DT will remain on Ch3. Fortunately, a 6 dB signal increase should help.

HLSJ combines a Lo-VHF band (e.g. Ch3) antenna with a Hi-VHF band
(e.g. VHF portion of R-S Combo)....but it doesn't pass UHF....so you would need
to also add a UHF-Only antenna (or figure out how to split VHF & UHF on R-S):
http://yhst-18278607509093.stores.yahoo.net/products-distribution-passive-component-separators-combiners.html
Note that UVSJ combines entire VHF band with UHF.

This allows fol. options:
Alt1: R-S combo in the attic may be adequate for Ch3 in Feb2009. You might also try
it with a Preamp....plus perhaps a few dB of input attenuation.

Alt2: Combine Ch3 antenna with R-S Combo for VHF-Only using HLSJ and then,
using UVSJ, combine that with a UHF-Only antenna (or the UHF-Only section of R-S
if you can). If you still have problems, you could try a Preamp as described above.

IDRick:
FYI: For digital signals, need to add 7 dB to convert from average to peak.
Hence -30 dBm average becomes -23 dBm peak....which are what cause the most glitches.

UHF:
Attic loss is difficult to estimate....based on numerous studies, I assume a loss of 13 dB (+/- 7 dB).
With "typical" attic loss, RX level would be about -36 dBm peak, which is at Max Sip for CM7777.
Lower attic loss would reduce dynamic range.....so a higher overload Preamp would be
"better"....if the weak signals were actually above the sensitivity level....

You would need to crank the numbers to see which Preamp MAXIMIZES dynamic range....
However, I doubt you are going to NEED the maximum dynamic range, cuz
"grey" zone stations are probably going to be too weak (zero fade margin, or even below threshhold).

The max signal level into your TVs is about -14 dBm which shouldn't degrade it's sensitivity.
Although meaningful specs are mostly unknown, try to keep below -10 dBm...
[-30 dBm average + 26 dB gain - 6 dB coax - 4 dB splitter = -14 dBm TV Input]

VHF:
Note there is only ONE strong VHF signal, which can be tolerated much more than two,
in addition to CM7777's higher max signal input level for VHF.

IDRick:

VHF:
Note there is only ONE strong VHF signal, which can be tolerated much more than two,
in addition to CM7777's higher max signal input level for VHF.

thanks for your reply holl_ands! I attached my post transition digital plot in the original post. The current plot has 4 high vhf signals (3 analog and 1 digital). All are in the green range and similar in strength. A pre-amp is definitely out of the picture until after the transition! Yes, you are correct about the stations in the gray range. I cannot pick up any of those in the attic or outdoors on the roof.

Thanks,

Rick

> The 7777 has the best noise floor on the market.

CM 7777 has 2.2 dB. What about the Research Communications at 0.4 dB ?

> Even adding a 4 way for more receivers would only up that 3db

2-way splitter: 3.5 dB
4-way splitter: 7.4 dB
(some splitters will be worse)

As long as the amp itself is not overloading, you can always add
a $2 attenuator to keep tuners from overloading. The problem is
keeping the amp itself from overloading.

CM 7777 has 2.2 dB. What about the Research Communications at 0.4 dB ?

Isnt that the pricey one that needs to be imported from England ?

(some splitters will be worse)

Yeah, only the ones marked 3.5 db loss will be 3.5 db. The common unmarked ones are 4.5 db or worse from what Ive read.

willscary:
JoinTenna insertion loss specs only say that it will affect adjacent VHF and UHF
up to 5 channels away. So the Ch11 JoinTenna should be okay, but the Ch31 Jointenna
will ALSO attenuate Ch30 (Analog W30BU), which may or may not concern you.
BTW: My fading memory seems to think it's about 0.5 dB off-channel, so you're
avoiding a sensitivity loss of about 1 dB using them AFTER the Preamps...
and out of the elements.

=====================================
To determine which are the "strong signals"...and how many....
I'll do current situation and I'll let you calculate Post-Feb2009.

a. First of all, ADD +7 dB to the strongest DTV signals (only) to convert
from average to peak:
TVFool Pwr(dBm): -43.8, -44.6, -48.2, -48.6, -37.8 (A), -38.9 (A), -51.5
Add 7 dB for DTV: -36.8, -37.6, -41.2, -41.6, -37.8 (A), -38.9 (A), -44.5

b. Then ADD 12.0 dB for the Antenna Gain (14.5 dBd) less Losses in Balun (1.5 dB),
Coax Ant-to-Preamp (0 dB) and (if indoors) a "guestimate" for indoor/attic loss.
I use a spread sheet for S.D. and L.A., but let's assume 91XG has 14.5 dBd gain for
ALL channels, bearing in mind it's a max value (A-D website says 16.7 dBi max):
-24.8, -25.6, -29.2, -29.6, -25.8 (A), -26.9 (A), -32.5
[FYI: dBd = dBi - 2.15 dB is presumed in tvfool calculations.]

c. Ignore those that are more than 6 dB weaker than the strongest....since their
contribution is minimal:
-24.8, -25.6, -29.2, -29.6, -25.8 (A), -26.9 (A)
So there are SIX strong signals with average strength of about -27.0 dBm.

Per my chart, CM7777 maintains maximum SFDR up to Max Input of -36.5 dBm for
two strong signals
or -43.5 dBm for SIX strong signals after reducing 7 dB (per foot note).

=====================================
So you are severely "overloading" the CM7777 by about 16.5 dB...YIKES!!!
HOWEVER, if all you want is the locals, you don't NEED very much dynamic range,
so the CM7777 will probably work anyway....(go figure....)

Note that after 26 dB Preamp Gain, it's outputting -1.0 dBm (average), which,
after attenuation by Coax downlead and RF Splitters might not be providing the
maximum dynamic range within your DTV Tuners....so a small amount (6 dB?) of
additional post-Preamp attenuation would optimize performance....
[I don't recall you saying how long your coax runs were....]

DTV Tuner input specs are hard to come by, but should remain below about
-10 dBm to -15 dBm to minimize intermod desensitization in the DTV's Tuner.
FYI: CECB Converter Box spec max is -5 dBm for a SINGLE signal, but doesn't
address intermod desensitization due to multiple signals.

Your local stations don't really need a Preamp. Instead of CM7777, you could
use UVSJ VHF/UHF Antenna Coupler:
http://yhst-18278607509093.stores.yahoo.net/pico-0389.html
http://www.solidsignal.com/prod_display.asp?PROD=UVSJ
[PS: JVI and Holland also make UVSJ, but insertion spec is higher.]

If you still want a Preamp for more distant stations, use the low-gain, high-overload
W-G HDP-269 (with a UVSJ), which maintains SFDR at -21.6 dBm with SIX strong signals.
[Or use a 3 to 7 dB attenuator on CM7777's input...each dB reduces intermods 3 dB.]

Thanks Holl-ands!

I had gone through your spreadsheet several times and come to the same conclusion you did, but a lot of people tell me I am plenty far enough away that the 7777 would benefit me.

That being said, I have already installed a 91XG pointed east at 43' and a Funke psp.1922 at 36' also pointed east. I get all my locals perfectly without the amp.

My plan was to add a 4228HD for channel 31 and another Funke for channels 7 and 9, both pointed NW. I planned on running separate cables and seperate amps from both of the NW antennas, then joining all 4 together with the jointennas. However, I installed an antenna for my niece on Friday and I was able to pick up stations to the rear quite well with the 91XG. I am now considering pointing the two existing antennas NW to recieve the out of market stations, adding the 7777, and seeing if I can get enough signal from the rear of these two antennas to receive both markets. I am thinking that perhaps with the strong stations to the rear, the attenuation will make all of the signals roughly -50 to -60 dbm. The 7777 might just make them all come in well.

Any thoughts?

Bill

Can you locate the published maximum input spec? In my market, all of my MATV competitors have just cannon-balled into the swimming pool and all guarantee that their MATV 8VSB heterodyne-processed headends will develop a guaranteed 0 dBmV at each wallplate with loads of eight to fourteen channels, which is a physical impossibility since their launch level is over 20 dB below the launch level of their analog, high powered strip amplifier headends, but I have some trouble convincing prospective new clients that not only is what they all are proposing impossible, it is also undesirable.

It seems to me that a year or two ago, someone here, probably Holl_ands, had observed that the set top box tuners commonly had varactor controlled bandpass filters on their inputs that varied in bandwidth from 10 to 20 MHz, so a somewhat larger than normal channel load won't have much affect on the maximum input levels as long as they are not adjacent channels.


I've been installing UHF additions to existing MATV headends for the last eight years. Until about a month ago, none of the manufacturers of commercial distribution amplifiers were even furnishing any maximum output ratings for digital loads for their amplifiers, so I was just knocking 8dB off whatever they gave for maximum output levels for similar sized analog loads.

Blonder Tongue now gives some maximum output level benchmark numbers for digital loads, and, oversimplifying greatly, they basically say to run the distribution amps about 4 dB weaker than you would with an analog load.

Unfortunately for us, comparing maximum analog and digital power levels is at best an apples and oranges comparison. With a single amplifier in an analog system, one is concerned with the level at which some undesirable artifact becomes visible on an analog picture, whereas with the digital signals, we are concerned with the level at which a more robust signal cannot be reliably decoded. The matter is further complicated by the fact that the amplifier manufacturers pick the engineering benchmark levels they furnish to be those appropriate for loads of equal strength channels, whereas those who are amplifying the signals from a home antenna are dealing with significant signal strength differentials. I once fed a couple of +20 dBmV peak analog signals into a Winegard 23 dB gain preamp (the infamous, undocumented AP4727) along with a real weak (maybe -30 dBmV RMS) digital signal and the digital signal got beat to paste, whereas when I fed the same three signals into a Channel Master 23 dB amp with similar published output ratings, the digital signal held up well.

>> CM 7777 has 2.2 dB. What about the Research Communications at 0.4 dB ?

> Isnt that the pricey one that needs to be imported from England ?

IIRC it was something like $400. I don't know where it is made.

The last Research Communications preamp I bought at the end of the summer was $160including shipping. They do come from England.
John

Today I turned my two existing antennas. My 91XG was turned to 326 degrees to pick up channel 31 (post trans) and my Funke psp.1922 was turned to 283 degrees to face channel 13 (post trans). I added the 7777 preamp.

All of the stations to the west that I wanted to receive now come in with a full 100% signal strength. I even receive channel 12.1 out of Rhinelander with a signal strength of 60 and I even receive analog channel 13 out of Eau Claire!

My local channels all come in with a signal of between 55-60. However, there is a channel that has occational dropouts. Channel 2 (physical channel 23) is the strongest channel I have. Yet it is the only one dropping out. I an guessing that channel 24 from the west is interfering with it. Any Suggestions? Perhaps moving the 91XG a bit more towards the north would help?

Would a distribution amp help at all?

(See my TV Fool plot in the earlier post)

AltAntMike:
Can you locate the published maximum input spec?
"Overload" spec is the point at which intermod noise floor is -46 dB below the input signal levels.
Unfortunately B-T, C-M and W-G use different methods, e.g. number of strong signals and
referencing either OUTPUT or INPUT signal levels. See spread sheet for spec summary
and conversions between common set of assumptions here:
http://www.avsforum.com/avs-vb/showthread.php?p=15005797

CECB single signal input spec is -5 dBm. I've also seen several "typical" tin-can tuner specs
for max single signals in the -10 to 0 dBm range, but I haven't seen any multiple signal specs.
Input bandwidth spec of 20 to 10 MHz (low to high frequencies) comes from Tuner specs
and engineering estimate re a single tuned inductor coil with a "typical" low-"Q" Varactor Diode:
www.rf114.com/lib/download.php?code=pds_tech&uid=111
http://www.micrometrics.com/pdfs/TV_AppNotes.pdf
http://www.infineon.com/dgdl/bb535series_bb555series.pdf?folderId=db3a304313d846880113d98 def1d0130&fileId=db3a304313d846880113d99d5153013c

Generally, you won't find publicly disclosed Tuner specs...here's an exception:
http://www.infineon.com/dgdl/AppNote_TUA6034_PartIII_ATSC.pdf?folderId=db3a304412b4079501 12b41fb6f4376f&fileId=db3a304412b407950112b41fb7563770&LOCATION=Search.AppNote_TUA6034_PartIII_ATSC.pdf#42255871355 586483477

======================================
FCC-OET tests on (unknown) DTVs & HD-STBs are found on OET website:
http://www.fcc.gov/oet/info/documents/

Several 2005/2006 DTVs were tested using multiple input signals in FCC/OET 07-TR-1003:
http://www.fcc.gov/oet/info/documents/reports/DTV_Interference_Rejection_Thresholds-03-30-07.pdf

From this you can "see" the tuner input attenuation vs frequency curve by looking at how
much interfering signal must increase in level when moving further away from tuned channel.

"Overload" spec is the point at which intermod noise floor is -46 dB below the input signal levels.
Unfortunately B-T, C-M and W-G use different methods, e.g. number of strong signals and
referencing either OUTPUT or INPUT signal levels. See spread sheet for spec summary
and conversions between common set of assumptions here:
http://www.avsforum.com/avs-vb/showthread.php?p=15005797.

It is not surprising that Blonder Tongue would tend to use different assumptions than would Channel Master and Winegard, because Blonder Tongue products are commercial products most commonly used to amplify larger, balanced loads.

Channel Master and Winegard used to sometimes use 5% sync compression as the overloading benchmark level for their amplifiers. Then, some of their literature changed the overloading parameter to -46dBc (decibels below carrier) cross modulation and coincidentally, the dBmV max levels were exactly the same for-46dBc cross mod as they had been for 5% sync compression.

A benchmark level of -46dB of cross mod may not be useful for digital signal amplification planning. -46dB is the S/N ratio for a TASO Grade 1 NTSC picture. But if digital signals can reliably be decoded with a noise floor just 16dB below the signal, then I would think they could similarly withstand cross mod signals that strong. I have seen other manufacturers furnish benchmark levels of -40 dBc for their amplification products.

Generally, if you load up a Blonder Tongue broadband amplifier to the point where compression becomes visible, each time you double the number of equal strength carriers, the max output goes down by 3dB. Thus, a workhorse, Blonder Tongue BIDA 450 or 550 can put out 46dBmV with a 60 NTSC channel load, 49 dB with a 30 channel load, and 15 dBmV with a 15 channel load.

In engineering satellite TV system, the benchmark level that manufacturers used to use for 3rd Order IMD was -35 dBc for analog systems and -40 dBc for digital systems. They used to claim that every time an input was increased by one dB, the 3rd Order IMD went up by 2 dB, but most engineers I have discussed this with dispute that relationship. They tend to agree that 3rd order IMD goes up or down by 3dB for each 1 dB change in input.

FWIW, if someone producing sales literature mistakenly substituted the term 3rd Order IMD for 2nd Order IMD, then all the rest of the manufacturers might have just copied it. They have done that with other products in the satellite and off-air signal processing business.

Amplified signals interact with each other in lots of ways. Blonder Tongue produces tables that show various intermod products for their distribution amplifiers under different channel loads. Blonder Tongue amplifiers use different amplification architectures from one another, and one of them is called "power doubling". A power doubling amplifier develops the same maximum output power before reaching unacceptable sync compression as do their similar models that do not "power double". I asked a Blonder Tongue engineer why anyone would pay more for the power doubling model, and he said that there is some intermodulation artifact incurred in a cascaded system that will be at a lower level in a system that uses power doubling architecture, and so more amplifiers can be cascaded when it is used. That doesn't affect the hobbyists here, but it means a lot to those distribution signals in a large plant, like a hospital or a college campus.

Way back in this thread, there is an article linked that says that a single digital signal, if amplified to the level at which it develops -40dBc of 3rd Order IMD on-channel, will develop -52dBc of 3rd Order IMD on the adjacent channels. That is important to know, because if you have adjacent digital channels that vary in strength by more than 12 dB, then the point at which the 3rd Order IMD from the strong signal will unacceptably degrade the adjacent channel will be a lower power level than the one at which it unacceptably degrades itself.

We are a long way from being able to mathematically determine the point at which any real, uneven loading of an amplifier will unacceptably degrade weaker signals in the presence of stronger ones.

Channel 2 (physical channel 23) is the strongest channel I have. Yet it is the only one dropping out. I an guessing that channel 24 from the west is interfering with it. Any Suggestions?

It sounds like a classic case of the preamp overloading your channel 23. Try a variable attenuator. A distribution amp would be the worse thing you could do in that type of situation.

Preamp overload? The strong station is facing away from the antenna. Shouldn't I have 20+ db of attenuation there? My signal strength is only about 60%.

Bill

Preamp overload? The strong station is facing away from the antenna. Shouldn't I have 20+ db of attenuation there? My signal strength is only about 60%.

Bill
Hmm, wouldn't that 60% actually be signal quality rather than strength?

Ed

...Channel 2 (physical channel 23) is the strongest channel I have. Yet it is the only one dropping out. I an guessing that channel 24 from the west is interfering with it. Any Suggestions? Perhaps moving the 91XG a bit more towards the north would help?...
You could be receiving out-of-phase signals from the off-targeted antenna.

The wavelength of channel 23 in RG-6 with a velocity of .78 is about 17-1/2". You can make up half a dozen or more jumper wires that vary in length in three inch or smaller increments and insert one at a time (edit) between one of the antennas and your antenna combining splitter and evaluate the performance of each. You might find that a few of them make the problem go away. If three of them make the problem go away, use the one in the middle. You probably will not need to cut the wires to smaller increments than that.

I did that successfully last Friday in a nineteen channel, three antenna headend where I had some unintended channel 27 signal leaking through my channel 30 bandpass filter and degrading the desired channel 27.

FWIW, if someone producing sales literature mistakenly substituted the term 3rd Order IMD for 2nd Order IMD, then all the rest of the manufacturers might have just copied it. They have done that with other products in the satellite and off-air signal processing business.

I don't think 2nd order intermod matters for OTA purposes at all, provided VHF-Hi, VHF-Lo, and UHF are amplified separately and filtered both before and after amplification. It only becomes an issue when you have more than an octave range.

I don't think 2nd order intermod matters for OTA purposes at all, provided VHF-Hi, VHF-Lo, and UHF are amplified separately and filtered both before and after amplification. It only becomes an issue when you have more than an octave range.

And similarly, 5% sync compression doesn't mean a hell of a lot when estimating degradation thresholds for digital signals. What I was getting at is that the rating info in sales literature accompanying consumer amplifiers doesn't deserve the credence we often give it here.

(BTW, 2nd Order does matter a little for me because I sometimes heterodyne convert UHF off-air to midband and superband, but I'm the odd duck here)

As a general rule, amplifier power limits furnished by manufacturers are generally attempts to determine the point at which a bunch of similar strength signals unacceptably beat up another similar strength signal, whereas in residential off-air applications, we are concerned about the point at which they beat up signals that are sometimes 40dB weaker, and I doubt I'll ever be able to mathematize such an analysis with any tools that are available to me.

Blonder Tongue and Winegard have discontinued manufacture of most of their distribution amplifiers that had three separate amplifiers for low, mid and highband. Any you can still buy are, "old, new stock" which is to say, they are new in the box but the box has dust on it.

Some useful math:

http://www.minicircuits.com/pages/pdfs/Zrl.pdf

Ron

You could be receiving out-of-phase signals from the off-targeted antenna.

The wavelength of channel 23 in RG-6 with a velocity of .78 is about 17-1/2". You can make up half a dozen or more jumper wires that vary in length in three inch or smaller increments and insert one at a time and evaluate the performance of each. You might find that a few of them make the problem go away. If three of them make the problem go away, use the one in the middle. You probably will not need to cut the wires to smaller increments than that.

I did that successfully last Friday in a nineteen channel, three antenna headend where I had some unintended channel 27 signal leaking through my channel 30 bandpass filter and degrading the desired channel 27.


Thanks! I tried this and it worked! The station, and all others, are now rock solid!

Thanks again.

Bill

What antenna would I use in my attic? I'm only interested in main locals. I was thinking the Channel Master 4228, since it's a powerful antenna that should cut through the attic and it can pick up hi-VHF. All the main locals, except one (KPXC) is located at ~200 degrees. Will the 4228 pick up KPXC which is at 59 degrees, or should I pick up a DB8, instead?

I don't think I'll need a pre-amp, but I'm not sure. Any advice on this?

http://img187.imageshack.us/img187/9031/tvfooldn3.jpg (http://imageshack.us)

Attics are always tricky; signals bounce around in ways that are not always predictable. Your best bet might be a smallish UHF/VHF-Hi combo antenna; they tend to have significant pickup off the back.

avJohnny: Howdy, neighbor!

An attic antenna can work as long as there are no signal-blocking obstructions in front of it (i.e., the "open" end of the antenna, which you would point to the south-southwest). These include metal vents or ducts; aluminum, brick, stone or stucco siding; tiles or a radiant barrier on the roof; or foil-backed insulation. Asphalt shingles, a wooden roof deck, wood-frame construction or vinyl siding cause only modest signal attenuation in our dry climate.

Avoid the DB8. While a fine antenna, it's designed for UHF only, which leaves out 7, 9 and 12 after the transition in February. There are less-expensive alternatives to the 4228 that will provide good results. Per nybbler's suggestion, have a look at a Winegard HD-7694. At 65 inches long and 36 inches wide, it's small enough to fit inside most attics. It also has better gain on 7, 9 and 12 while providing solid signals on the rest of the channels.

At an ERP of 1 megawatt from 9 miles out, KPXC-DT 59.x is probably strong enough to be received on the back side of any antenna you decide on.

You don't need an amp unless the coax downlead from the antenna to a single TV would be more than 150 feet long, or you'll be connecting more than one tuner to the antenna. If so, the only one that will work well in your area is the Winegard HDP-269. Higher-gain pre-amps are likely to overload because of the strong signal from KPXC, among other stations.

What antenna would I use in my attic?

The 4228 is a UHF only antenna. You have three VHF stations. Some will suggest that a 4228 works on VHF, which is true, but it's worst VHF channel is 7 (KMGH) and the antenna will get less signal in the attic. Try it at your own risk.

Take a look at the Winegard HD76XX series of Hi-VHF/UHF antennas.

The Antennacraft HBU-22 might even work for you.

Add KPXC with a 4221 and a Jointenna tuned to channel 43.

Per nybbler's suggestion, have a look at a Winegard HD-7694. At 65 inches long and 36 inches wide, it's small enough to fit inside most attics. It also has better gain on 7, 9 and 12 while providing solid signals on the rest of the channels.

Sounds good. What's the easiest way to mount this antenna in an attic? Do I need to get any special mounting device?

What's the easiest way to mount this antenna in an attic?

Some folks simply place the antenna on the floor, which isn't advisable: You want as much separation as possible from any electrical wiring to reduce AC interference. You also want the ability to turn the antenna at least a little bit for precise aiming after it's installed. That means using brackets and masts.

I have two antennas, VHF and UHF, in separate attic locations. I picked up small, inexpensive antenna-mast wall brackets (sold in sets of two) at the home center. RS carries them as well. The brackets are screwed to roof rafters, above the antennas. For cheap masts, I cut up a 10-foot length of 1" I.D. white PVC water pipe. (For outdoor mounts, though, only a steel antenna mast and heavy-duty brackets will stand up to wind loads in the long term.)

You can either hang the mast from a single bracket screwed into a roof rafter and clamp the antenna to the bottom of the mast, or use both wall brackets attached to supports or trusses with the antenna mounted above the brackets. With the latter method, you may need to nail horizontal wood scraps to the supports/trusses wide enough to accept the bracket screws. If such a location makes for cumbersome installation or aiming, it may be best to attach longer boards a foot apart horizontally between two supports, then attach a bracket to the center of each. The brackets need to be level wherever you attach them.

Some folks simply place the antenna on the floor, which isn't advisable: You want as much separation as possible from any electrical wiring to reduce AC interference.

In most attics you can see if there is any nearby wiring underneath the location you chose.


You also want the ability to turn the antenna at least a little bit for precise aiming after it's installed.Which is a lot easier if the antenna is not attached to anything.

Ken, a lot of attics in homes on the CO Front Range, where we both live, have blown-in, loose fiber glass or cellulose insulation that just sits on top of the second-floor ceiling joists and drywall. There's frequently no attic floor at all. You can't see the wiring without digging for it.

As you might guess, working in such a space isn't exactly a day in the park. :eek:

As you might guess, working in such a space isn't exactly a day in the park. :eek:

Yes, it's not fun wading through a bunch of insulation, hoping you don't crash through the drywall floor. You have to find the narrow 2x4s by touch, and then, if you're concerned with energy savings, you have shift the insulation around to fill your walking path on your way out. In my last home I added a few outlets and moved some cabling around for the master bedroom system. You literally have to dig out a trench to do that kind of work.

Ken, a lot of attics in homes on the CO Front Range, where we both live, have blown-in, loose fiber glass or cellulose insulation that just sits on top of the second-floor ceiling joists and drywall. There's frequently no attic floor at all. You can't see the wiring without digging for it.

As you might guess, working in such a space isn't exactly a day in the park. :eek:Not even a little. I would say in those cases mounting an indoor antenna from the top of the structure would be a better idea.

What antenna would I use in my attic? I'm only interested in main locals. I was thinking the Channel Master 4228...

I used a Terk HDTV-O mounted inside my attic. It's a combination UHF /VHF-hi antenna and gets all the main channels from Lookout Mtn area perfectly (well almost, KRMA is dicey until they fix their transmit tower). I have almost the same TVFool results as you.

The HDTVo package includes an adjustable mount and switchable preamp for about $75 from Amazon. As Ken H noted, it was easiest to mount it hanging down from the attic rafters, then use the adjustments to aim according to TVFool.

Oftentimes, the single 91XG will outperform a stack. (Based on my testing)

Looks like you are missing the first director on your 91XG.

Bill, you should be fine using the CM 7777 with your setup. You are 37 miles from your nearest station. I'm using the 7777 with virtually the same setup you have (pair of Triax Unix 100s instead of the 91XGs, and a single Funke PSP 1922) and I'm 3 - 5.5 miles from my local TV and FM radio towers. I do have a few overload issues with some analog channels, but to date, no noticeable overload issues caused by the 7777 with local or distant digital channels.

I've attached a pic of my setup, which does include a single 91XG about 2.5 feet below the Triax stack and about 4 feet above the Funke 1922.

Steve

Oftentimes, the single 91XG will outperform a stack. (Based on my testing)

Looks like you are missing the first director on your 91XG.

On occasion, I have found the same to be true. Sometimes the single antenna will outperform the stack, but not very often. For local reception, the single might be a better performer because the azimuth reading is not as critical. But if attempting to tame multipath and/or receive distant stations, the stack will generally deliver better results. Here are some examples I was able to capture this morning.
http://www.wtfda.info/showpost.php?p=6715&postcount=13

And, yes, the first director on my 91XG is missing. Last year this antenna was mounted on a mast instead of a tower and was fairly close to a number of tree limbs. During a thunderstorm last year, a tree limb swiped the front of the antenna and broke it off. I have the two pieces but to date I haven't repaired it.

Steve

(I first posted this on another thread, but thought I should also post it here because it might help a few others.)

I have been making measurements of digital signals with my Sadelco 719E signal level meter (SLM) for about a year. Even though it is calibrated for peak reading of analog signals, I have found that it is very useful for making comparative measurements of antennas and digital signals:
http://www.avsforum.com/avs-vb/showthread.php?t=1084674

I would like to have a new SLM that is designed for digital signals, but it is not now in the budget. But what about the people that don't have either? I keep thinking of a poster who lived close to the transmitter towers and had an attic antenna. He was having trouble receiving signals. Was it that the signals were so strong they were causing overload because they only had to go thru wooden siding or were they too weak because they were blocked by aluminum siding or an aluminum foil vapor barrier? I made some signal measurements with my Apex DT502 to see how it would do as a SLM. After the antenna, I used a switched attenuator (actually 2 in series) with 3dB steps (as in the Kelvin link in my signature) going to a splitter and then to the DT502 and the SLM; first in a strong signal location:
Attenuator Quality Strength dBmV dBm
dB % %

0 100 84 +12.5 -36.3
3 100 84 +9 -39.8
6 100 83 +6.1 -42.7
9 100 83 +2.9 -45.9
12 100 83 +1.4 -47.4
15 100 81 -2 -50.8
18 100 78 -4.9 -53.7
21 100 74 -8.5 -57.3
24 100 69 -12 -60.8
27 100 65 -15 -63.8
30 100 61 -18.5 -67.3
33 100 59 -20.5 -69.3
36 100 54 -24 -72.8
39 100 51 -27 -75.8
42 100 46 -30 -78.8
I next added a preamp to simulate a very strong signal bringing it up to +36 dBmV, but the DT502 signal strength never went any higher than 84%. I was also looking for signs of overload, but didn't see any. I would have to drive about 100 miles round trip to pick up an extremely strong signal, but it doesn't seem worth the trouble right now. The ultimate test of a tuner would be to see how it would handle a very weak signal when other very strong signals are on the band. That's for another day.

and then in a weak signal location:
Attenuator Quality Strength dBmV dBm
dB % %
0 100 59 -18.3 -67.1
3 100 55 -21.8 -70.6
6 100 50 -25.0 -73.8
9 100 44 -29.0 -77.8
12 100 42
15 67 33
18 30 18
21 0 0 Dropout
I was able to test a 2nd DT502, and the results were similar: It maxed out at 87% strength at +2.2 dBmV with an increasing signal, and held 100% quality down to 51% strength just below -30 dBmV with a decreasing signal.

It looks like the DT502 can be used as a SLM. Its tuner is even more sensitive than my SLM.

CAUTION: As Trip correctly pointed out to me, this CECB doesn't allow you to add other channels after the scan. See wiki other features note code "-N" of CECB comparisons:
http://en.wikipedia.org/wiki/Comparison_of_CECB_units

I have an Sansonic FT300A that also has separate signal quality and signal strength meters. Unlike your examples above, the signal quality varies a lot more, and can sometimes be less than half of signal strength. I wonder what that signifies ?

I have an Sansonic FT300A that also has separate signal quality and signal strength meters. Unlike your examples above, the signal quality varies a lot more, and can sometimes be less than half of signal strength. I wonder what that signifies ?
At my location the signal quality also varies a lot because my antenna is aimed across a well-traveled street which causes a lot of reflections from the tops of the cars when they pass by. But as long as the signal is strong, I don't see any change on the monitor. I do notice a change in PQ on my marginal channel which is why I went across the road to make the weak signal measurements without the multipath interference from the cars.

The quality bar is usually related to bit error rate/ratio (BER). Each manufacturer gets to decide what percentage equals what level of error rate. It would be necessary to connect the FT300A and the DT502 to a splitter to see how they each react to changes in the signal as the attenuation is increased. The ideal test setup would be a 4way splitter (with DA if necessary) connected to the 2 boxes, a signal level meter, and a BER meter. This would tell you everything you would want to know about the relationship between the 2 bars on each box, the signal level, and the BER.

While I certainly agree that there are far better tools for measurement, the CECB's can be very useful for finetuning antenna location. In my case, I have broadcast towers in two directions (200 and 270 degrees). My DIY 4-bay does a nice job of receiving signal from both directions with proper placement in the attic. The APEX 502 was invaluable for optimizing signal strength of my two lowest channels (1 at 270 and 1 at 200 degrees) and deciding final antenna location/orientation.

Signal quality readings from the APEX also had practical application. My antenna is connected to two tvs and a computer capture card. Anything less than 100 on signal quality scale results in audio and video dropouts with the capture card. I get marvelous recordings with proper placement of the antenna (optimized signal strength and signal quality = 100). I'm sure top quality equipment could fine tune my setup even further. I'm satisfied with a $20 tool versus a several hundred dollar tool, especially for a one time use.

Downunder in .au land, they have a good understanding of the importance signal quality, BER, and MER:
http://www.dtvforum.info/index.php?showtopic=18627 see post #11
http://www.dtvforum.info/index.php?showtopic=11399&st=360&start=360 #366 & 369
http://www.hillsantenna.com.au/arbitrage/pages/61 BER
http://www.hillsantenna.com.au/arbitrage/pages/60 MER
http://users.tpg.com.au/bitek500/Downloads/HDTM%20instal.pdf p4 DVB-T digital cliff
http://www.bbc.co.uk/rd/pubs/papers/pdffiles/crn-dvbtm.pdf ATSC vs DVB-T, excellent charts on p3
http://www.wowvision.tv/signal_strength_meters_BER.htm Signal strength meters and BER

The factors that reduce signal quality and cause a higher BER are:

1. Improper signal level: A weak signal will cause a poor signal-to-noise ratio; a signal that is too strong can overload a tuner or preamp. A nearby FM transmitter can also cause overload, which would require an FM trap.
2. Reflections from multipath problems.
3. Impulse noise in the reception area.

I don't know what kind of signals you have but I suspect that they are affected by 1. and 2.

When I was testing the DT502 with my CM4221 antenna on my marginal signal (13.1 on RF41) back at my apartment, I got:
Signal Quality 60%
Signal Strength 55%

I had aimed the antenna with my SLM, but when I rotated the 4221 slightly to the right I got:
Signal Quality 100%
Signal Strength 56%
Note the BIG change in signal quality with only a slight change in signal strength.

It seems that the signal quality indication is a more sensitive aiming tool than signal strength, because it shows the increase in BER from multipath reflections. In my situation the BER is affected by the weak signal, the fixed multipath reflections, and the changing multipath reflections (Which shows the need for the new ATSC M/H standard).

Hi Guys,
I am pretty bad with my geography and I need a favor here. Can anyone help me with the interpretations and tell me if they are situated within 15 degrees of each other?

Transmitter A is located at 01° 21' 07"N, 103° 45' 57"E while
Transmitter B is located at 01° 36' 12"N, 103° 32' 50"E

Do u think the transmitters are within the beamwidth of channelmaster 4228? And if I decide to get 4228, can it receive signals from both transmitters say if I point it towards that single direction?

Thanks for helping me out, have a wonderful year ahead!

regards
samstom

It depends on where you are in relation to the transmitters in order to say whether they are within 15 degrees of each other. If you are exactly between them then they will be 180 degrees apart. The further away you are from them, then the closer together they will appear to be.

Go to TVfool.com, enter your address and it will tell you the degrees the towers are from you. Then if the values are within 15 they will be within 15 degrees of each other.

While at TVfool, look at the post-transition chart. The 4228 is designed for channels above 14 while some users claim success with channels 12 & 13. It will be important to know the channels the towers are transmitting on post-transition to determine if the 4228 is your best option. Post the TVfool results here and others will assist you with an antenna selection/options.

Depending on the sign of the Longitude those locations are either in Singapore or in the Pacific Ocean West of Equador.
John

Hi Guys,
I am pretty bad with my geography and I need a favor here. Can anyone help me...
To find the latitude and longitude using tvfool, click on the line that contains the callsign of the transmitter and up will come another page giving transmitter ERP and the coordinates. When I click on the WREG-DT post transition line in the Memphis table I get Coordinates: 35.181200 -89.832308.

You can also go to Tiger Map Server Browser at:
http://tiger.census.gov/cgi-bin/mapbrowse-tbl to find the coordinates.
For example, it gives (Centered at Lat: 35.10560 Lon: -90.00699) for Memphis. Note the all important minus sign before the 90.

To answer your original question hdtvluvr has given you good advice:
Go to www.tvfool.com, enter your address and it will tell you the degrees the towers are from you.

Guys,
Well, I am currently working in Singapore and sites like Tiger Map Server Browser or tvfool do not work for me.

I just need to know if the transmitters are pretty close to each other and decide if I want the 4228 and my gf from Michigan can have it shipped to me. I'll see if I can use google earth to plot out a map and maybe the kind folks here can help me out.

In that case, use google earth to pinpoint the towers. Transfer those points to a map of the area that also includes your location. Draw a straight line from your location to each of the tower locations. You can then use a protractor and measure the angle. You can print a protractor from here:

Protractor (http://www.ossmann.com/protractor/)

Guys,
Well, I am currently working in Singapore and sites like Tiger Map Server Browser or tvfool do not work for me.

I just need to know if the transmitters are pretty close to each other.

It depends on your location. Determine your own location and use this tool:
http://www.fcc.gov/mb/audio/bickel/distance.html

Do that for each transmitter, determine the angle between them, and then the antenna choice will be much clearer. There are VHF channels in Singapore, so the UHF only 4228 may not be the best choice.

The original transmitters in Singapore are on a hill toward the north, near the WW II memorial. Others are on high rise buildings near Orchard Street.

Those two locations are seperated by about 23 miles.
John

Hi Guys,
I am pretty bad with my geography and I need a favor here. Can anyone help me with the interpretations and tell me if they are situated within 15 degrees of each other?

Transmitter A is located at 01° 21' 07"N, 103° 45' 57"E while
Transmitter B is located at 01° 36' 12"N, 103° 32' 50"E

Do u think the transmitters are within the beamwidth of channelmaster 4228? And if I decide to get 4228, can it receive signals from both transmitters say if I point it towards that single direction?

Thanks for helping me out, have a wonderful year ahead!

regards
samstom
You need to provide YOUR location as well....
You might find the following on-line calculator to be useful:
http://www.movable-type.co.uk/scripts/latlong.html

BTW: The FREE downloadable Radio Mobile program is designed for
predicting signal strength (like tvfool), including when blocked by terrain:
http://www.cplus.org/rmw/english1.html
http://www.pizon.org/radio-mobile-tutorial/index.html
Here is how I set it up:
http://hdtv.forsandiego.com/messages/1/6255.html#POST27302
Archiving deletes the zip files...but they won't help you anyway.
It AUTOMATICALLY downloads low-rez SRTM-3 topographic files and there is a link
to download hi-rez SRTM-1 files.

Here are some R-M examples:
http://www.avsforum.com/avs-vb/showpost.php?p=6206737&postcount=111
http://www.avsforum.com/avs-vb/showpost.php?p=6286128&postcount=2828
http://hdtv.forsandiego.com/messages/1/7063.html#POST36187

I have attached 2 files. Point B is 10 miles from me while Point A is 30 miles from me. The landscape of Singapore is flat but there are a lot of tall buildings on the island so reception tends to be a bit shaky. I live pretty high up , no problems for me, I receive rather clear signals, no grains, with my 4221 other than multiple ghosts towards the right of my TV screen after the 50 storey units are built.

The 4221 you now have has plenty of gain for 10 and 30 miles. Have you tried turning the antenna away from the building to get rid of the ghosts ?

I hope my mapping helps!

It helps alot. I had assumed that you wanted only Singapore stations. Now I see that you are trying for Malaysia as well.

The two sites that you want are in line such that a 4228 will work. Yet, the 4228 is a UHF antenna. There are VHF stations at site A, I don't know about site B.

Attached is a picture that I took of the two TCS VHF transmitters at site A.

How did u get the photos from inside?

Thanks for reminding me of the name of the Hill.

I toured the transmitter building during a consulting contract for TCS.

The station link that you provided is very interesting!

Preparing for 17Feb, I analyzed High-Performance (i.e. not small) DIY
Zig-Zag Hi-VHF Band Antennas (such as would be installed in an ATTIC).
See post in DIY VHF Thread:
http://www.avsforum.com/avs-vb/showthread.php?p=15451710

Although I've read many NEC Sim antenna studies over the years,
this the first time I've had time to analyze what I built in my parents attic
some 40-years ago....comments would be appreciated....

======================================
PS: I also confirmed W-G YA-1713 Hi-VHF Antenna NEC Sim results posted on HDTVPRIMER wherein gain across Ch13 is dropping precipitously:
http://www.hdtvprimer.com/ANTENNAS/COMPARING.html
Presuming we can believe what we THINK we are modeling in NEC Sim....

I'm still looking at how to simulate the 50pF capacitor on the output
of my antenna's 1:1 Balun, which seems to make the situation even
worse....any suggestions???
And what value should be used for Crossover Transmission Line
Impedance...and more importantly, Why??? The antenna impedance is all over the
place in the YA-1713, and Sweeping the impedance value doesn't yield a clear "best".

About ghosting from multipath signal reception:

Assuming SD broadcast in NTSC, i.e. 525 lines 29.94 times per seconds (or exactly 15734 Hz). That is 63.56us per line, of which 52.66us are actually the visible video.
http://www.ntsc-tv.com/images/tv/sync-wf.gif

Assuming the visible image is 640 pixels wide (although this is not digital TV),
1 pixel is 1/640 of the image width, i.e. 1 pixel is ~82.28ns long.
That is about 24.7 meters (81 feet) at the speed of light.

If you had a ghost image 5% of the image width (not your 16:9 screen but the 4:3 screen), you would be victim of a second signal path that has travelled an extra 790 meters (0.49 miles). Every 1% of ghosting is roughly 0.1 mile at light speed (0.981 mile, 158 meters, or 518 feet).

When you have very thin ghost image, it may be explained by nearby buildings reflection.
When you have a largely offset ghost image, you are more likely victim of a geographical reflection, like a mountain side or diffraction from a mountain top.

You can ignore people telling you to move your antenna a few dozen feet away from walls or buildings in order to eliminate 'visible' ghost image. However, that recommendation stands when you are having a bad reception but don't quite know why. Nanoseconds or less order ghosting can mess up ntsc colors, luminance or audio by cancelling/interfering with any of those signals inside the 6 Mhz channel, while atsc DTV could have a high error rate for similar reasons (hence the upcoming 6th generation of atsc decoding that can deal with multipath more efficiently).

...If you had a ghost image 5% of the image width (not your 16:9 screen but the 4:3 screen), you would be victim of a second signal path that has travelled an extra 790 meters (0.49 miles). Every 1% of ghosting is roughly 0.1 mile at light speed (0.981 mile, 158 meters, or 518 feet)...

Frank Baylin's late 1980s book on Satellite TV has a chart in it that shows how many inches of horizontal ghost displacement on different, common sized CRT screens converts to how much extra distance that the multipath signal traveled. From that, you can generate an ellipse and then intersect that with the direction from which the ghost signal is coming and that will be the location of the reflecting object.

I used that methodology to determine that Byrd Stadium in College Park, MD was the reflecting object, even though I could not see the stadium because of the vegetation. I then moved the mast about a hundred feet closer to the TV transmitters and that location was clear of most of the reflection.

I could do that because I had the budget to work with, since that antenna sourced a 400 drop MATV system. For most of you, the best you can do to mitigate a ghost is to rotate your antenna so that the undesired signal component falls in an antenna reception "null". Good luck doing that when the analog signals are gone.

Hey folks,

Pretty new to OTA and just wondering a few things about optimizing my setup.

I put a CM4228HD in my attic, and after dialing it in I can get all my locals great (Greensboro, NC) plus Roanoke, VA. The transmitters locally are south of me, but pointing it north let me pull in Roanoke and maintains great signal strength for the locals (using my Mits TV to measure, not sure how good of a measure that is).

When setting up, I routed it directly to the TV for my readings. Next I wanted to split it for the other TVs in the house. Signal seemed great from the ANT to the TV (each run is about 50'), I figure no preamp is necessary. So I hooked all of the rooms that are homerun to a Antronix ARA4-8 (4 way, 8 db gain) powered amp (previously used for the cable).

Rechecked the signal strength, all seemed good. So up till this point, no problem.

In one room, I had wanted to split the signal again, one for my DirecTv AM21 (which internally splits it again, but that's besides the point as I didn't get that far), the other leg to the TV. I checked the TV, and lost a bunch of channels. So clearly, splitting it again is too weak. (As it turns out, the AM21 is just fine splitting it internally as long as it is fed directly from the ARA4-8.)

I was really thinking that a decent signal into the ARA4-8 would be fine to split again given the gain. Some of my channels are near 100% signal strength so I'm assuming a preamp is out? Any tips on how to deliver a better signal throughout the house so it can withstand another split? Or is it the best I can do OTA in the attic?

Thx for the advice!

I was really thinking that a decent signal into the ARA4-8 would be fine to split again given the gain. Some of my channels are near 100% signal strength so I'm assuming a preamp is out? Any tips on how to deliver a better signal throughout the house so it can withstand another split?

Run individual cables directly from the distribution amp's ports to each TV or STB. That second splitter is apparently chewing up the gain from the amp, and maybe then some. Home runs from a single split point are the best workaround for issues like these. Also, try to get the amp as close to the antenna as you can, because the cable between the two system components loses signal at the rate of roughly 1.5 dB for every 20 feet in the UHF band.

A pre-amp is not a good idea in addition to the distribution amp based on what you said about high signal strengths from some channels. Together, they would likely result in tuner overload at one or more of the receivers, causing loss of more channels.

I looked up the specs on the ARA4-8, attached below, and you won't find a better performer among pre-amps than what you have now. (Rarely does one see such a wealth of information in a spec sheet, always a solid hint of a good product.)

Run individual cables directly from the distribution amp's ports to each TV or STB. That second splitter is apparently chewing up the gain from the amp, and maybe then some. Home runs from a single split point are the best workaround for issues like these. Also, try to get the amp as close to the antenna as you can, because the cable between the two system components loses signal at the rate of roughly 1.5 dB for every 20 feet in the UHF band.

A pre-amp is not a good idea in addition to the distribution amp based on what you said about high signal strengths from some channels. Together, they would likely result in tuner overload at one or more of the receivers, causing loss of more channels.

I looked up the specs on the ARA4-8, attached below, and you won't find a better performer among pre-amps than what you have now. (Rarely does one see such a wealth of information in a spec sheet, always a solid hint of a good product.)

Thanks Don! Very helpful feedback. Sounds like things are reasonably as best as I can get them as is. That loss-rate of 1.5db per 20 feet is much higher than I would've guessed. The amp is within 6 feet of the antenna, but the runs from the amp are fairly long (50 feet, on average).

I'll keep everything as a home run. I've seen various posts regarding signal strength vs signal quality. To me it seems surprising that a reasonably strong signal (say, 75-80%) drops almost completely with a splitter, but probably not worth the effort to dig into it (I tried 2 different splitters, too, just to see if it was the splitter -- same effect.) Thx again!

I'm still looking at how to simulate the 50pF capacitor on the output
of my antenna's 1:1 Balun, which seems to make the situation even
worse....any suggestions???

It's just a small increase in insertion loss, and shouldn't affect the modeling in any significant way.

And what value should be used for Crossover Transmission Line
Impedance...

The crossover transmission line impedence is determined by the geometry of the transmission line -- the radius of the two conductors and the distance between them.

Is there an antenna that will give me better UHF performance in my attic than a Winegard HD-7084P?

I currently have this antenna with a Winegard AP-8700 preamp in my attic.

Using a Zenith DTT901, I found that I had a 20-33% signal strength on all of the UHF channels I want to receive, which isn't enough to get a lock (TV fool map is attached with the channels I want circled in red). I do have at least some signal on all channels I want to receive.

Is there something else I can add in my attic that will give me a better UHF signal than the 7084P? Maybe a CM 4228 with 7777 preamp? I am ok with spending whatever here if I can keep it in the attic.

My other option is to install a Winegard Square Shooter on the roof, is this a better idea?

Is there an antenna that will give me better UHF performance in my attic than a Winegard HD-7084P?

I currently have this antenna with a Winegard AP-8700 preamp in my attic.

Using a Zenith DTT901, I found that I had a 20-33% signal strength on all of the UHF channels I want to receive, which isn't enough to get a lock (TV fool map is attached with the channels I want circled in red). I do have at least some signal on all channels I want to receive.

Is there something else I can add in my attic that will give me a better UHF signal than the 7084P? Maybe a CM 4228 with 7777 preamp? I am ok with spending whatever here if I can keep it in the attic.

My other option is to install a Winegard Square Shooter on the roof, is this a better idea?

There is no way that you can mount it outdoors? That may make the difference, because of the height difference, plus the getting rid of the loss due to the attic??

There is no way that you can mount it outdoors? That may make the difference, because of the height difference, plus the getting rid of the loss due to the attic??

Due to spousal constraints a roof mount would have to be the last option :). My order of preference would be:

1. CM 4228 in attic.
2. Square shooter on roof.
3. CM 4228 on roof.

I'm just not sure if I'm wasting time trying to put something like the CM 4228 in the attic.

My other option is to install a Winegard Square Shooter on the roof, is this a better idea?

No, it isn't. The SS is not nearly as good a performer as what you have now.

The pre-amp may be overloading with KUTH so close by; its signal is thousands of times stronger than the strongest desired station. Try taking the amp out, including the power inserter, and run the downlead directly from the antenna to the CECB to see what happens.

I'm with the previous poster: The 7084 probably needs to go outside, and up high. Noise margins that low (in the "NM dB" column) usually rule out an attic antenna, regardless of model. For reference: Under ideal circumstances, NMs no lower than 15-20 dB are typically necessary for successful attic installations. The threshold is even higher in situations like yours where there is no line of sight. (That's what "1-edge" and "2-edge" mean.)

Rather than moving the 7084, could I use a CM 4228 mounted outside? The 4228 will be an easier sell to the spouse, and the 7084 was hard enough to get in the attic--not sure I can even get it out! :)

The pre-amp may be overloading with KUTH so close by; its signal is thousands of times stronger than the strongest desired station.
Thanks for the tip, I'll try this.

Rather than moving the 7084, could I use a CM 4228 mounted outside?

Sure. It's got better UHF gain than the 7084 and should be adequate for receiving Fox 13.1 from outdoors after the transition. Be aware that it's a fairly heavy antenna, so if you get lots of high winds, be sure to mount it on a steel mast and sturdy, well-anchored mounting brackets.

Forgot about those wide elements on the 7084. Yah, it would be a challenge to pull it out of most attics without damage. :(

Its time for another round of Name That Antenna!


http://i302.photobucket.com/albums/nn88/EscapeVelo/IMG_0443.jpg

Out of curiosity, does anyone (or is it feasible) mount an antenna such as the CM4228 (that's fairly flat) parallel with the roof, much like a solar panel?

I'm happy with my reception in the attic so have no plans to change, but just curious. My roof pitch is incredibly high, and having such an option would meet WAF.

Out of curiosity, does anyone (or is it feasible) mount an antenna such as the CM4228 (that's fairly flat) parallel with the roof, much like a solar panel?

I'm happy with my reception in the attic so have no plans to change, but just curious. My roof pitch is incredibly high, and having such an option would meet WAF.

There are smaller antennas that can mount along a rake or ridge of the house, depends on what you need for your location...

Depending on where you live, it could also get buried in snow and not preform at ALL in the winter, in theory, a 4228 mounted that way could work, it would prolly make a little gain loss, or in some cases, tipping back can increase signal.....

Other then those thoughts, I have not seen antenna such as you describe....

Out of curiosity, does anyone (or is it feasible) mount an antenna such as the CM4228 (that's fairly flat) parallel with the roof, much like a solar panel?


It would still work, but like noted, youll lose some gain.

Its time for another round of Name That Antenna!



Heh, it would be better if we had a picture of it fully assembled and right side up. Do you know if its North American or European ?

It looks like that antenna is skewed towards the high uhf channels, 52 - 83, soon to be completely out of date.

Wade-Dehli HD-2500?

I have an antenna on the roof. I think it's a ChannelMaster, it's huge. I am splitting the signal and sending it 2 places. My most desired channel, KCET HD, comes in @ ~60 and so goes in and out a bit. My problem is this: I am only a few miles from the transmission station in Pasadena, but there are trees on my lot and a hill in the way. Ironically, I have an indoor antenna that does get KCET HD, but it's in the other room and it doesn't get a lot of the other channels.

Any advice appreciated. Thanks.

I have an antenna on the roof. I think it's a ChannelMaster, it's huge. I am splitting the signal and sending it 2 places. My most desired channel, KCET HD, comes in @ ~60 and so goes in and out a bit. My problem is this: I am only a few miles from the transmission station in Pasadena, but there are trees on my lot and a hill in the way. Ironically, I have an indoor antenna that does get KCET HD, but it's in the other room and it doesn't get a lot of the other channels.

Any advice appreciated. Thanks.

Can you post your tvfool results? Also, any chance you know the model of the antenna or can post pictures?

I have a Samsung plasma tv and receive broadcasts using an OTA antenna. I use one antenna, amplifier and a rotator to align with two different transmitters approximately 60 degrees apart. I receive multiple channels both UHF and VHF from both(Phoenix and Tucson). The problem is I have to memorize channels each time I change the antenna angle. This Samsung does not allow the manual addition of channels. I do not want to memorize each time, so I have two thoughts about circumventing this problem; first, two antennas, each pointing at a different transmitter, or second, placing an HDTV tuner before the Samsung in the current configuration. The tuner must allow the manual addition of channels. Thoughts and suggestions would be appreciated.

Always do the cheapest thing first. How far are you from each set of transmitters? The problem with combining antennas is that you open yourself to more multipath possibilities. However, if you have the spare antenna lying around, then by all means stick a splitter/combiner in the line, hang 'em both and give it a try.

If you get too much multipath, you could always use an A/B switch between the two antennas instead of combining. Then just switch it back and forth as necessary as the set scans the channels. Which should be pretty fun to try, though the wife might get a laugh from watching you.

It would depend on your distance from the towers and the terrain.

A Winegard YA-1713 will give you 0 dbd gain at channels 7-13 if you point it directly between the stations. Along the same lines, a Channel Master 4221 will give you about 4-5 dbd in gain over most of the UHF channels when pointed in the same midpoint direction. This would be perfectly fine if you ar in a good reception area.

http://img266.imageshack.us/img266/219/radardigital22cs7.png

I live on the bottom floor of a large 2 story 4-plex. Immediate terrain is generally flat, or low grade hills. I'm surrounded by many large 2-story dwellings. Mounting in attic or outdoors are not an option. I only care about local nets + PBS and KCAL9. So.... Winegard ss-3000 my best bet? I'm currently using a DIY rack that works okay, but requires a ton of fiddling depending on what station I need.

I'm very new to OTA reception and HDTV in general, if you can't tell. Thanks everyone for all the help.

EDIT: Ignore the subject heading; I meant the SS-3000, not the SS-2000

Hey guys, need an outdoor antenna recommendation. I need VHF-channel 11 and 13. Do they make antennas that only cover like 11-13. I have a channel master 4248 in the attic and getting baltimore channel 38 uhf great at 58 miles. No breakups. I live pretty high up. But next month they will be switching to channel 13. Thanks

Hey guys, need an outdoor antenna recommendation. I need VHF-channel 11 and 13. Do they make antennas that only cover like 11-13. I have a channel master 4248 in the attic and getting baltimore channel 38 uhf great at 58 miles. No breakups. I live pretty high up. But next month they will be switching to channel 13. Thanks

Antennacraft Y10-7-13

Winegard also makes one, but it's deficient on channel 13.

Antennacraft Y10-7-13

Winegard also makes one, but it's deficient on channel 13.

Thanks

I have a Samsung plasma tv and receive broadcasts using an OTA antenna. I use one antenna, amplifier and a rotator to align with two different transmitters approximately 60 degrees apart. I receive multiple channels both UHF and VHF from both(Phoenix and Tucson). The problem is I have to memorize channels each time I change the antenna angle. This Samsung does not allow the manual addition of channels. I do not want to memorize each time, so I have two thoughts about circumventing this problem; first, two antennas, each pointing at a different transmitter, or second, placing an HDTV tuner before the Samsung in the current configuration. The tuner must allow the manual addition of channels. Thoughts and suggestions would be appreciated.
You might try doing a partial scan.
Tune to the actual unused RF channel just before the channel you wish to add then start a scan. The scan should begin at the tuned channel and then detect the next active channel, adding it to your list (and remapping it to the virtual channel). As soon as the TV detects the new wanted channel, stop the scan and exit menu. It should have added the one channel to your list without erasing any others.

I've successfully done this on many Samsung TV's and tuners.

Good luck.

-ML

I just hooked up my Terk HDTVO Antenna rated Blue Zone to my Samsung HDTV and I received with the help of TVfool.com 11 digital channels and 9 analog . I installed the HDTVO antenna in my attic and pointed it toward syracuse, figuring I am about 5-10 miles from the binghamton towers and I picked up 2 syracuse stations. I hooked the amplifier up as directed but do not have it on as it seems to overload most channels.

12.1 WBNG (CBS) 4 miles
20 WBGH (NBC)
26 W26bS(TBN)
34.1 WIVT (ABC)
40.1 WICZ (FOX)
40.2 MYNetwork
42.6 (Assuming PBS Radio)
42.7 (Assuming PBS Radio)
43.1 WNYS(MyN-Syracuse) 54.6 miles
46.1 WSKG(PBS)
46.2 WSKG(PBS)
46.3 WSKG Create(PBS)
68.1 WSYT(Fox Syracuse) 54.6 miles

I am tried pulling stations from the scranton/wilkesbarre area couldnt get anything in the few times I tried, probably due to my antenna being in the attic. Is there anything I can do to pull in more channels or should I be happy with my results? I attached my tvfool results for analysis. I really would like to pull in more syracuse stations or scranton, but the scranton stations i have to look thru the local towers, is that a problem?


Thanks for listening

Sustorm,

Your antenna is doing quite well given the challenging reception area that you live in and an attic install. To get more stations, you probably will need to move the antenna out on to the roof this spring. I would seriously consider the tigerbangs solution for deep fringe if you want more OTA. see: http://www.highdefforum.com/local-hdtv-info-reception/14818-tigerbangs-prescription-deep-fringe-reception.html

Thanks Rick for the fast reply, when using TVfools offline google maps, I only show 4 channels that have a reception coverage area for my home that I am not currently receiving, two in Elmira and two in the Scranton PA Area.

Now that we're really getting the cold weather, if your having signal problems, don't forget to look at the dish to see if there's snow.
I bought the AC powered Hot Shot from the SatPro and haven't had any problems since.:D

http://i241.photobucket.com/albums/ff124/rgjraccoon/6039680c.jpg
http://i241.photobucket.com/albums/ff124/rgjraccoon/d9722eab.jpg
http://i241.photobucket.com/albums/ff124/rgjraccoon/b3d63314.jpg
http://i241.photobucket.com/albums/ff124/rgjraccoon/53293dad.jpg
http://i241.photobucket.com/albums/ff124/rgjraccoon/11304308.jpg
http://i241.photobucket.com/albums/ff124/rgjraccoon/971fbbb7.jpg

Yep, those are all DTV ready. At least for the channels they can receive. But, they probably are not even analog ready for today's TV markets, since there are now, and will be in the digital future, channels in the UHF band.

Hey guys, need an outdoor antenna recommendation. I need VHF-channel 11 and 13. Do they make antennas that only cover like 11-13. I have a channel master 4248 in the attic and getting baltimore channel 38 uhf great at 58 miles. No breakups. I live pretty high up. But next month they will be switching to channel 13. ThanksWhere do you live? WJZ-13 will be operating at "very low" power after the transition until their new directional antenna is installed.(9.8kw) Once the directional antenna is installed the power will be increased (28.8kw), but the directional pattern of their antenna will favor areas east of Baltimore.

WBAL-11 will also be running at a low power level (5kw-omni), but so far there are no plans to increase power. Things should be quite interesting!!

Antennacraft Y10-7-13

Winegard also makes one, but it's deficient on channel 13.Thanks Tower Guy,

Do you prefer the Antennacraft over the Winegard YA-1713 in general? How does it compare to the YA-1713 on channels 7-12?

Glen

Where do you live? WJZ-13 will be operating at "very low" power after the transition until their new directional antenna is installed.(9.8kw) Once the directional antenna is installed the power will be increased (28.8kw), but the directional pattern of their antenna will favor areas east of Baltimore.

WBAL-11 will also be running at a low power level (5kw-omni), but so far there are no plans to increase power. Things should be quite interesting!!

I live in Dillsburg,Pa. I get WJZ very well with no breakups at 58 miles with an attic antenna. Why in the world would they wait to install this antenna?

I live in Dillsburg,Pa. I get WJZ very well with no breakups at 58 miles with an attic antenna. Why in the world would they wait to install this antenna?They have to limit their power to areas west in order to protect WWPX-12 Martinsburg, WV.

I'm wondering if I will have issues at my location????????

They have to limit their power to areas west in order to protect WWPX-12 Martinsburg, WV.

I'm wondering if I will have issues at my location????????

I hope that I'm still able to recieve them. WJZ is a great channel. I can't get my harrisburg cbs because of a mountain. I don't even get a blip on WV channels. I would hope that from Frederick, MD to Dillsburg,Pa they still shoot their signal as strong as before. There is a mountain that would stop any interference of WV channels.

Does the TVFool site take into account these sort of directional vs omni broadcasting changes as well as power changes?

I'm considering adding OTA and I'm in a fringy area per TVFool but I'm wondering if it's going to be actually worse than currently predicted.

tnx
jtm

I hope that I'm still able to recieve them. WJZ is a great channel. I can't get my harrisburg cbs because of a mountain. I don't even get a blip on WV channels. I would hope that from Frederick, MD to Dillsburg,Pa they still shoot their signal as strong as before. There is a mountain that would stop any interference of WV channels.

I agree. WJZ has been my CBS replacement for a while since WHP 21 is broadcasting on channel 4 till the change over. Where exactly are you that you can't get WHP...I'm down at Lake Meade (south of you) and it was one of my strongest stations before I switched over to a UHF antenna (SBGH/DBGH)?

BTW, I thought WJZ broadcast towers were closer to Baltimore, not Frederick.

Craig

alDoes the TVFool site take into account these sort of directional vs omni broadcasting changes as well as power changes?

I'm considering adding OTA and I'm in a fringy area per TVFool but I'm wondering if it's going to be actually worse than currently predicted.

tnx
jtmYes, they do take those things into account.

I find the predictions to be fairly accurate, more so with UHF.

BTW, I thought WJZ broadcast towers were closer to Baltimore, not Frederick.Yes, WMAR-2, WBAL-11, & WJZ-13 all broadcast from the same tower on TV Hill in Baltimore. I think WBFF-45 is on the same tower, but not 100% sure.

Yes, WMAR-2, WBAL-11, & WJZ-13 all broadcast from the same tower on TV Hill in Baltimore. I think WBFF-45 is on the same tower, but not 100% sure.

What I was referring to is they should cover from the mountain from Frederick to Dillsburg. They do that now. If that is not the case I won't be covered by any CBS station. I live West of rt 15 at the base of the mountain. At the very north-western edge of York County. I get all Baltimore stations with an attic antenna. Nbc 11 being the worst and WJZ the best.

I agree. WJZ has been my CBS replacement for a while since WHP 21 is broadcasting on channel 4 till the change over. Where exactly are you that you can't get WHP...I'm down at Lake Meade (south of you) and it was one of my strongest stations before I switched over to a UHF antenna (SBGH/DBGH)?

BTW, I thought WJZ broadcast towers were closer to Baltimore, not Frederick.

Craig

When I lived in Thurmont MD- WHP analog came in great. There is a mountain directly west and north of me blocking cbs and abc in Harrisburg.

Here is a doc on WJZs new antenna. I can't make much out of it.
http://fjallfoss.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=624669

Are you over behind the Boy Scout camp? That would kinda mess up things, like WHP, WITF and WHTM. I guess I should consider my location very lucky! I'd love to have a little more altitude...I can only get WJZ, WNUV, and WMPT at around 50%, on a good day.

Craig

BTW, thanks for the WJZ attachment. Looks like I'm awful close to not getting it after transition.

Are you over behind the Boy Scout camp? That would kinda mess up things, like WHP, WITF and WHTM. I guess I should consider my location very lucky! I'd love to have a little more altitude...I can only get WJZ, WNUV, and WMPT at around 50%, on a good day.

Craig

BTW, thanks for the WJZ attachment. Looks like I'm awful close to not getting it after transition.

Yes, pretty close to the camp. I get good reception here but if they change their direct of the antenna I will be in trouble. In reading the attachment what line do you think is the cut off line? Dotted or red? Its hard to understand.

I have an old BELL expressVU dish which is no longer in use. can i connect it to my new sony HDtv with tv tuner in order to receive over the air HD signal? I am very new at this and thinking if there is a use of this abandon dish... thanks for help.

thmswng,

No. A dish antenna is for microwave frequencies such as come off a satellite. OTA TV channels are much longer wavelength frequencies known as UHF and VHF. You will need a TV antenna.

Yes, pretty close to the camp. I get good reception here but if they change their direct of the antenna I will be in trouble. In reading the attachment what line do you think is the cut off line? Dotted or red? Its hard to understand.

I'm thinking the red line. I don't quite understand the dotted 5 mi extension. Maybe one of the many engineers looking on could clarify that for us. I'm more worried that if the waiver doesn't pass, we'll be totally excluded (see last map).

Craig

I'm thinking the red line. I don't quite understand the dotted 5 mi extension. Maybe one of the many engineers looking on could clarify that for us. I'm more worried that if the waiver doesn't pass, we'll be totally excluded (see last map).

Craig

I just found this on the Wash/Balt thread. It looks better once they go to full power. Probably more up to date also.
Attachment won't work, page 261 of that thread.

Thanks Tower Guy,

Do you prefer the Antennacraft over the Winegard YA-1713 in general? How does it compare to the YA-1713 on channels 7-12?

Glen


Look here for the data on the YA-1713.

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

Note that the net gain drops from +9.7 db on channel 10 to -6 db on the top of channel 13.

I'd expect that the performance of the Winegard and Antennacraft would be similar on channels 7-12.

I'm thinking the red line. I don't quite understand the dotted 5 mi extension.

The FCC has already granted the waiver to 28.8 KW. WJZ has an application for temporary operation at 9.8 KW, but using their old analog antenna. It will take a few months after the analog shutdown to switch to this power.

http://fjallfoss.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=695542

The 5 mile dotted line is the maximum that the FCC would allow them to extend their coverage. Note that the actual proposed coverage just touches the line.

The FCC has already granted the waiver to 28.8 KW. WJZ has an application for temporary operation at 9.8 KW, but using their old analog antenna. It will take a few months after the analog shutdown to switch to this power.

http://fjallfoss.fcc.gov/prod/cdbs/forms/prod/getattachment_exh.cgi?exhibit_id=695542

The 5 mile dotted line is the maximum that the FCC would allow them to extend their coverage. Note that the actual proposed coverage just touches the line.

I'm still confused on this. Will WJZ cover the 5mile area to the black dotted line or will they give up those potential viewers when they go full power?

Re: are they DTV ready.

Yeah, they are all vhf antennas. Theyre going to miss a lot of uhf programming. That vhf-hi/lo antenna from the late 1940's is in need of repair, its sagging.

I'm still confused on this. Will WJZ cover the 5mile area to the black dotted line or will they give up those potential viewers when they go full power?

It depends on the direction.

Re: are they DTV ready? :):confused::)

I'm surprised no one noticed the old twin lead coming down the masts of most of the antennas I posted. Some, still have nice, orderly, twisted downlead. Others are just dangling in the breeze. So, there's some RG-6 in order, to start.

Not much ice or severe wind here in Canon (read: microclimates) so these old soldiers are still up long after their counterparts elsewhere got turned into beer cans. While it's dry here, there's still got to be some corrosion to clean up.

So, not are they only missing the U's, they'd probably be pretty numb in the V dept., too. I love these old beasts, and I'd love them even better hanging from the ceiling of a TV/radio museum or the big garage I'll never have.

I'm guessing, after looking at old catalogs, the oldest of the bunch is from the late 50's to early 60's. That's still 50 years.

The oddest of the bunch in my book is the last one, the Finco "Bedspring", the one that looks a bit like the beginnings of a humongo 4228. Prior to moving here, I'd only seen one in the last 40 years. Andthat includes living in fringe areas my first 20. There are at least four in this area.

I'm guessing, after looking at old catalogs, the oldest of the bunch is from the late 50's to early 60's. That's still 50 years.

I think that folded dipole vhf-hi-lo is a little older than that, late 1940's maybe when it first came out ??

When I was a kid, we used to have a double bay vhf bowtie similiar to the one pictured, except it had straight reflectors not the x type. It pulled in stations fairly well from over 70 miles away.

Guys,
Is it possible for the strongest channel, which means that this channel is easily received to suffer from the worst multi-path? I do not have serious multipath with those that are harder to receive. But this particular one which is easier to get on my 4221, I see more ghostings than anything.

Do they make such a thing as a cut to channel antenna that is geared toward maximizing reception of one channel only? Like a channel 13 Yagi? Where does one find these if they exist? Thanks

Do they make such a thing as a cut to channel antenna that is geared toward maximizing reception of one channel only? Like a channel 13 Yagi? Where does one find these if they exist? Thanks

Yes, they exist, or at least they used to exist, but are becoming very difficult to locate. Stark Electronic still has the Winegard "CC" series listed and some Blonder Tongue models on their website, but little info about ordering and availability. You could call them and check to see if they are still available.
http://www.starkelectronic.com/vhf.htm

Guys,
Is it possible for the strongest channel, which means that this channel is easily received to suffer from the worst multi-path? I do not have serious multipath with those that are harder to receive. But this particular one which is easier to get on my 4221, I see more ghostings than anything.

Yes

There may be some things you could to to the 4221 to make it better but more than likely you will have to go to a more directional antenna.

Hi ALL,

I am currently using a 91XG yagi antenna. I am behind hills and trees with no line-of-sight to transmitters (at best 2 edge reception). I have one UHF channel that I have poor reception on (real channel 44) and the 91XG barely does the job for this channel. I can move it up/down as little as 1 foot from where it is currently positioned and will get almost nothing. I have found a "hot-spot" that barely works for the channel.

I was considering buying a CM4228 or trying to build a double bay Gray-Hoverman antenna but believe that it will not be an improvement for the following reason... Please correct me if you think I am wrong here. That is why I am posting this.

Bay antennas seem to be designed for uniform signal field strength situations where the signal from many elements are combined to increase gain. The field strength in the area of the hot-spot where my antenna is located does not appear to be uniform. I believe that the yagi (91XG) works as well as it does only because its directors can be inserted in the hot-spot and it only has one driven element. I am given to understand with antennas that have multiple elements that if some elements have a higher signal than others that the extra signal will be broadcast out thru the weaker elements causing an effective averaging of signal across all elements and a reduction of gain from what would be expected in a uniform signal field. With a bay antenna would this apply when it is in a non-uniform signal field?

In short, do you think a 91XG yagi would perform better in a grossly non-uniform signal field (when in a hot-spot) than a CM4228 bay antenna?

dmatch

Where is the best place to pick up the old style Channel Master 4221? I meant to do this earlier, and now it seems to be getting a bit harry. Solid Signal is sold out. Amazon ditto.

I am currently using a 91XG yagi antenna. I am behind hills and trees with no line-of-sight to transmitters (at best 2 edge reception). I have one UHF channel that I have poor reception on (real channel 44) and the 91XG barely does the job for this channel. I can move it up/down as little as 1 foot from where it is currently positioned and will get almost nothing. I have found a "hot-spot" that barely works for the channel.

I was considering buying a CM4228 or trying to build a double bay Gray-Hoverman antenna but believe that it will not be an improvement for the following reason... Please correct me if you think I am wrong here. That is why I am posting this.


Well thats the thing with the corner reflector yagis, you have to find that hot spot. In my experience, the bay type antennas are better for getting signals thru the trees, in that there is more front facing metal presented towards the transmitter and at different levels, increasing the chances that it will fall into a hot spot.

keeper:

Wade Antenna Inc. in Brantford, Ontario manufactures consumer VHF channel-cut antennas. They have both 5 and 10 element antennas offering 7.5 dBd and 10 dBd gain respectively.

The channel 13 model would be the 5Y13S or the 10Y13S. You can find more information here: www dot wade-antenna dot com/Wade/cutchannel.pdf [Sorry, I couldn't post link as I have < 3 posts.]

I have a 10Y13S myself and paid C$75 retail for it. These antennas are good for eliminating adjacent channel interference because their frequency response is so narrow.

YUL-STL

keeper:

Wade Antenna Inc. in Brantford, Ontario manufactures consumer VHF channel-cut antennas. They have both 5 and 10 element antennas offering 7.5 dBd and 10 dBd gain respectively.

The channel 13 model would be the 5Y13S or the 10Y13S. You can find more information here: www dot wade-antenna dot com/Wade/cutchannel.pdf [Sorry, I couldn't post link as I have < 3 posts.]

I have a 10Y13S myself and paid C$75 retail for it. These antennas are good for eliminating adjacent channel interference because their frequency response is so narrow.

YUL-STL

Thanks

Zip code is 71260.


My wife's parents are wanting to install a Outside antenna.
With this zip code, can someone give me some advice on what antenna to purchase?
I considered the CM 4221HD or CM4228HD. I do have some VHF channels to deal with specifically VHF 7 which will be 8 after 2/17 per TVFOOL. COM, Channel 11 and channel 13.

I am trying to keep this as simple as possible. They are both pushing 80 years of age.

Here is the tvfool for your zip. I'll let the big guns give you antenna advice because I have to see about dinner.

You can do it yourself with more accurate results if you enter your exact address at tvfool.com. The exact address will not show up when you post it as an attachment on this thread. Click on "save" for post transition to combine all the info and select the results as an attachment up loaded from your hard drive to the manage attachments window.

The Channel Master 4220, 4221, 4228 old Made in America style are becoming harder to find already.

Zip code is 71260.
With this zip code, can someone give me some advice on what antenna to purchase?

Let's assume that you don't want a rotor.

Start with a 7-69 antenna aimed at 170 degrees. A Winegard HD76XX series would be a good option. It's best mounted on the roof.

Next you need a second UHF only antenna for NBC & MyNet. A 2 or 4 bay bow tie array is one choice. Aim it at 11 degrees. Try to add it to the 7-69 antenna with a splitter used as a combiner. This antenna could be mounted in the attic.

If you want a CW, you'll have to go on the roof with a third antenna. (Most 80 year olds don't watch CW.)

I currently have a Radio Shack 190 antenna (outside, 20 feet high) pointed at 320-340. It receives 13, 14, 21, 36 and 38, the stations I am interested in. Channel 38 is problematic, with macroblocking and other problems occasionally. What antenna would best receive those stations? TVFool below.

I currently have a Radio Shack 190 antenna (outside, 20 feet high) pointed at 320-340. receive those stations? Your antenna may be just fine. You may just need a rotator. Have you ever tried pointing your antenna more towards 356 degrees to see if channel 38 improves?

Thanks for the reply.

If I go more north I start to lose the others. I'm hoping for a wide angle UHF that can see ch 13.

I think a DB4/4221 may be a good choice, wide beam width of the 4221 should make it easier to aim in between... How many devices are hooked up to your antenna? If more then a few, you may want a low gain amp, the HDP-269 would be a good choice, if you are splitting the signal more then 2 ways

Thanks for the reply.

If I go more north I start to lose the others. I'm hoping for a wide angle UHF that can see ch 13.

13 is strong enough, I would bet that a paper clip in the rf connector would pick it up some of the time, so I think any outdoor UHF antenna should be ok with it....

How many devices are hooked up to your antenna? If more then a few, you may want a low gain amp, the HDP-269 would be a good choice, if you are splitting the signal more then 2 ways

IMHO, with four stations strong enough to overload any preamp, I think I'd ditch any thought about a preamp unless you are using rabbit ears inside, even then, with four of them you might get an overload with that....I wish I had his problem...

Craig

Thanks for the reply.

If I go more north I start to lose the others. I'm hoping for a wide angle UHF that can see ch 13.

This may be close to what you're thinking.

Antennacraft HBU-22

Thanks for the help. Right now I have an RS inline amp feeding 3 TVs, although there are but 2 hooked up. Would a Clear Stream 1, or DB2, or CM 4220 do the job?

Ok, I've now moved.

I have a DB4 and a Motorola BDA-S1 broadband amplifier. I'm having a few dropouts on the more distant Chicago stations (60 miles South) but the antenna is temporarily indoors while I get my cabling situated. I imagine it will clear up with the antenna moved outdoors.

The problem is right now I will have a few VHF stations after the transition. Channel 10 from Milwaukee is staying VHF and channel 7 from Chicago is reverting to VHF IIRC. What should I look at for an antenna? At another location in this city I was able to pull in channel 10 with just the DB4.

I am guessing a set of rabbit ears zip tied to the top of or the reflector on the DB4 with a VHF/UHF combiner should help? Should the combiner be placed before or after the amplifier?

I'm in Plant City, FL about 40 miles from the towers that would give me ABC, CBS, Fox and NBC. I'd like those 4, at minimum.

Here's my plan: I'm wired for cable. I was going to get a new signal splitter, leave the cable feed for my cable-modem, and run the new splitter from an attic-based antenna to the rest of the house (that's three drops in 1400 sq feet of space).

Tv Fool is attached.

What's my cheapest option? Is DIY necessarily cheaper than store-bought? How do I best aim my antenna without fancy equipment?

Thanks for the advice!

Don't know where the 40 mile figure came from but you're less than 20 miles from the antenna farm in Riverview--only more distant station is CBS channel 10, they are close to 40 at 37. If there are no obstructions between you and Riverview then a Radio Shack V/U combo would probably go in the attic. When the digital switch occurs we will have 4 stations on VHF, the rest on UHF. I'm NW of you in Wesley Chapel and I use separate VHF-UHF antennas with a rotator. if you only want an attic antenna I would go to good old Radio Shack and get there smallest VHF/UHF combo and try it in the attic to see how well you receive digital channels--make sure you can take it back if it doesn't suit you. I tried their U-75R here (UHF only) and didn't suit me so I got the separate antennas. All you can do is try thier combo and see how it works; channel 10 will be the bugaboo (their antenna is in tarpon Springs) maybe but you might be able to split the difference between Riverview and Tarpon Springs and still recieve good signals. I found out already that regardless of what people are saying these digital signals are finicky and using an antenna especially in the attic is a trial and error deal around here.

What's my cheapest option? Is DIY necessarily cheaper than store-bought? How do I best aim my antenna without fancy equipment?

Your cheapest option is an Antennacraft HBU-22 plus an Antennacraft Y5-7-13. Aim them using a compass or topo map and a nearby landmark.

To add the two antennas you can try a splitter backwards. If that doesn't work for you, a Jointenna tuned to channel 10 will be needed.

Can you post your tvfool results? Also, any chance you know the model of the antenna or can post pictures?

I currently have a Winegard PR-7000 (lite green zone) and checked TV fool for my channels post 2/17/09. I found a replacement antenna PR-7013 that is supposed to be better, but I'm not sure it really is. I get good reception on analog and digital channels presently and the antenna is in the attic. If I get another one, I'd probably put it up there too.

Currently use an older Panasonic Analog TV, Panasonic EZ48V DVR, Dish 501 PVR, Yamaha V663 Receiver, and a Tivax STB-T8 CECB. I also need to know how to hook this mess up properly in order to record on the DVR with the CECB NOT in standby. The DVR records fine if the CECB is in standby, but does NOT record if the CECB is on. I obviously have something connected incorrectly.

Here is the TV Fool info and info on my current antenna. Will it be good enough for the transition?

Linda

Currently use an older Panasonic Analog TV, Panasonic EZ48V DVR, Dish 501 PVR, Yamaha V663 Receiver, and a Tivax STB-T8 CECB. I also need to know how to hook this mess up properly in order to record on the DVR with the CECB NOT in standby. The DVR records fine if the CECB is in standby, but does NOT record if the CECB is on. I obviously have something connected incorrectly.

Linda

Isn't the Panasonic EZ48V a DVD recorder with a built-in ATSC and NTSC tuner rather than a DVR? If that's the case, you don't need to and shouldn't use the CECB with the Panasonic EZ48V. You'll get better quality recording using a direct connection between the antenna and the Panasonic EZ48V, which can also be used like an expensive converter box itself (but you should use the cheaper Tivax instead).

(I couldn't find a Panasonic EZ48V DVR on the first page of a Google search.)

Isn't the Panasonic EZ48V a DVD recorder with a built-in ATSC and NTSC tuner rather than a DVR? If that's the case, you don't need to and shouldn't use the CECB with the Panasonic EZ48V. You'll get better quality recording using a direct connection between the antenna and the Panasonic EZ48V, which can also be used like an expensive converter box itself (but you should use the cheaper Tivax instead).

(I couldn't find a Panasonic EZ48V DVR on the first page of a Google search.)

Sorry, It is a Panasonic DMR-EZ48V and when the Tivax is connected and turned on, the Panny starts up from its scheduled timed program but then does not record until I turn the Tivax to standby. This is even though I am recording a digital channel.

I guess I don't understand the way the signals all work. The only way I can figure to connect everything, is to run a splitter and send one end of the antenna to the DMR and one to the Tivax box. I'm still concerned however that the timed program will not work.

The Panny recorded fine and started up correctly BEFORE I put the Tivax box in the mix.

Yes, the Panasonic DMR-EZ48V has a digital tuner and I've been watching digital channels with it and recording digital channels. My TV is analog, so I wanted to be able to watch a digital channel (after the transition) while the DMR was turned OFF in order to start a recording. If it is turned off, then I don't have any way except a converter box to watch digital channels. Am I really messed up or what?

Linda

Linda, Are you running the antenna signal through the Tivax and on to your DVD recorder? If so, the CSEB is blocking the antenna signal when it is on as the RF output if supplying a channel 3 or 4 for older TV's with no other inputs. When the CSEB is off it passes the entire antenna signal especially if it is a newer "analog pass" model.
I think you have already hit upon the solution of installing a signal splitter and running separate antenna cables to the CSEB and DVD recorder. You will loose a bit of signal with the splitter but that is happening anyway inside of the Tivax. Your signal and antenna set-up appear to be very strong.
Good Luck from down I-25 in El Paso.

I currently have a Winegard PR-7000 (lite green zone) and checked TV fool for my channels post 2/17/09. I found a replacement antenna PR-7013 that is supposed to be better, but I'm not sure it really is. I get good reception on analog and digital channels presently and the antenna is in the attic. If I get another one, I'd probably put it up there too.

Currently use an older Panasonic Analog TV, Panasonic EZ48V DVR, Dish 501 PVR, Yamaha V663 Receiver, and a Tivax STB-T8 CECB. I also need to know how to hook this mess up properly in order to record on the DVR with the CECB NOT in standby. The DVR records fine if the CECB is in standby, but does NOT record if the CECB is on. I obviously have something connected incorrectly.

Here is the TV Fool info and info on my current antenna. Will it be good enough for the transition?

Linda

Linda:

Your signals are very high, your antenna attic mounted should be good for all the stations at 110 heading... You would not want to use an amp either, as it would almost certainly overload... I would wait and see how it works, if you get dropouts on the lower stations on the chart like KAZQ-DT, you could get a little higher gain antenna... Most attic installs eat up at least -13dB of signal, so that puts that station near -56dB, which most CECBs and good tv tuners should lock on pretty easily...

Linda-

You don't need a splitter.

Take your coax cable from the antenna and connect it to the EZ48V's "RF IN" jack.

Install a piece of coax cable from the EZ48V's "RF OUT" jack and connect it to the CECB's "RF IN" jack (it might be called "Ant In" or something similar, I'm not sure).

Install a piece of coax cable from the CECB's "RF OUT" jack to the antenna input on your TV.

The EZ48V will see the antenna signals at all times with this, and the EZ48V will either pass the antenna signal unaltered through to the CECB at all times, or if it has a modulated signal (a channel 3 or channel 4 signal) coming out of its RF OUT jack, you can push a button on your EZ48V's remote to switch it into passthrough mode just like we've all been doing with VCRs for the last 20 years.

Linda-

You don't need a splitter.

Take your coax cable from the antenna and connect it to the EZ48V's "RF IN" jack.

Install a piece of coax cable from the EZ48V's "RF OUT" jack and connect it to the CECB's "RF IN" jack (it might be called "Ant In" or something similar, I'm not sure).

Install a piece of coax cable from the CECB's "RF OUT" jack to the antenna input on your TV.

The EZ48V will see the antenna signals at all times with this, and the EZ48V will either pass the antenna signal unaltered through to the CECB at all times, or if it has a modulated signal (a channel 3 or channel 4 signal) coming out of its RF OUT jack, you can push a button on your EZ48V's remote to switch it into passthrough mode just like we've all been doing with VCRs for the last 20 years.

That is the way Systems2000 said to do it too. I think right now I DON'T have the antenna directly to the EZ48V.

The passthrough seems to be my problem, and of course I won't know for sure until I am able to switch the coax around behind everything!

Currently, the EZ48V turns on at the set time with no problem, but if the Tivax is "ON" (w/green light) then the EZ48V just sits there and will NOT record until I put the Tivax on standby. I still want to watch Digital channels while the EZ48V is recording a timed program. If the Tivax is on standby all I will receive is snow!

Wouldn't the splitter provide a clearer picture, or will I lose too much signal by using a splitter?

I don't know how to figure the dB on signal loss and noise etc., so I am trusting all you A/V "specialists" to help me out. LOL

Linda

Thank you all for your help! Very much appreciated and I hooked up components like most of you all said to do....

Antenna - ->DMR-EZ48V - ->Tivax STB T8- ->Dish PVR501 - ->TV

It all works great! Thank you again. Next time, (IF..God forbid) I'll ask the questions first and try to be more specific.

I think the DTV people for the government and all others should post a "help" with a simple diagram for those of us who are using a recorder with a digital tuner and a converter box who have the same situation as I do. Believe me, no one I found has that scenario.:rolleyes::rolleyes::D:D:D

About 6 or 7 years ago, my antenna was struck my lightning. We had it installed a few years prior when we had DirecTV so we could pull in the local channels. At the time it was struck by lightning, we had switched to cable and were rarely using the antenna. I don't know when we found out that the antenna stopped working, but it hasn't worked since.

The antenna was professionally installed so I can hesitantly assume that it was properly grounded. However it hasn't been able to pull in any signal (analog or digital) and the rotator doesn't work. I'm not an electrician or an antenna expert but what kind of repair am I in for if I want to get it working again? Can I do it myself?

About 6 or 7 years ago, my antenna was struck my lightning. We had it installed a few years prior when we had DirecTV so we could pull in the local channels. At the time it was struck by lightning, we had switched to cable and were rarely using the antenna. I don't know when we found out that the antenna stopped working, but it hasn't worked since.

The antenna was professionally installed so I can hesitantly assume that it was properly grounded. However it hasn't been able to pull in any signal (analog or digital) and the rotator doesn't work. I'm not an electrician or an antenna expert but what kind of repair am I in for if I want to get it working again? Can I do it myself?

Kind of hard to say. If it was directly struck by lightning, I'd suspect you'd have a melted ball of metal. Antennas are surprisingly simple so if it doesn't work and shows no sign of damage, it could be a connection issue -- corroded or such. The rotor is another story -- can't be sure without looking at it.

I'd use tvfool to check out your location, dial it in manually so you know which station you should get, and try redoing the connections. If that fails, you may need a new antenna.

...was professionally installed so I can hesitantly assume that it was properly grounded.

Double check it was done properly, refer to the end of
http://www.hdtvprimer.com/ANTENNAS/basics.html

About 6 or 7 years ago, my antenna was struck my lightning. We had it installed a few years prior when we had DirecTV so we could pull in the local channels. At the time it was struck by lightning, we had switched to cable and were rarely using the antenna. I don't know when we found out that the antenna stopped working, but it hasn't worked since.

The antenna was professionally installed so I can hesitantly assume that it was properly grounded. However it hasn't been able to pull in any signal (analog or digital) and the rotator doesn't work. I'm not an electrician or an antenna expert but what kind of repair am I in for if I want to get it working again? Can I do it myself?

the 300 to 75 ohm transformer on the antenna could have easily been destroyed by a nearby or partial lightning strike. also the coax could have been damaged any where along its length.

go to tvfool.com and look for what real channels will exist after the transition. does your current antenna (assuming it still works) fit the antenna that you will need? if they are in more than one direction (i assume because you had a rotor) then you will need to replace or fix (if you aren't an electronics diy then that would be a bad idea, give it to someone for parts) the rotor.

for this antenna you can do a test now, go up to the antenna, replace the 300 to 75 ohm transformer (just need a screwdriver and maybe pliers). the coax end that connects to the antenna may have to be redone. even without a working rotor if the antenna is pointed towards a station you should be able to see if you get a signal.

if you could do now using an NTSC TV to check if it works it would be easier. trying to test antenna with an unknown digital receiving situation would be more difficult (you don'r see picture as quickly and easily as with analog NTSC).

Hi, Can I make a 2 or 4 bay UHF antenna by connecting 2-4 of R.S. UHF Outline Bow-Tie Antenna's to one 300 to 75 balun?

I dont have the materials for a DYI but I thought this might work as well. I am looking to pick up channels 18, 19, 36, and 44 (zip code 13790) I currently pick up 19 and 44 with a TERK HDTVO and I am looking to do some experimenting with the UHF channels.

These channels are in different directions, but my real question is;

would connecting 2 or 4 of the UHF Bowties from radio shack to 1 balun work as a 2 or 4 bay antenna? Here is the link to the RS bowtiehttp://www.radioshack.com/product/index.jsp?productId=2062017

Any comments would be appreciated Thanks!

Also posted in the how to build UHF topic

Hi, Can I make a 2 or 4 bay UHF antenna by connecting 2-4 of R.S. UHF Outline Bow-Tie Antenna's to one 300 to 75 balun?

You can, but without a lot of modeling work, the phasing line spacing would probably be all out of whack and performance would suffer badly. Plus they cost at least $3.95 each. Much cheaper to buy house wiring at the home center and follow a modeled design.

thanks!

Hi. Hope I can get some recommendations on an outdoor antenna that will be split to 3, possibly 4 tv's. I do not want an amp or rotor in this setup. Trying to keep it simple. This week I'll be getting rid of DirecTV and going with only OTA until FiOS is up in my city by end of summer. Would like to maximize channels received.

I'm 31 miles west of Boston. Current OTA is with a DirecTV HR10-250 and Zenith SS through an east facing first floor wall. I get all the Boston locals now but have signal issues sometimes with Fox 25-1. All these stations are roughly 31 miles and 121 degrees.

I also have a 20 LG TV also on a SS (different location) east facing wall. This setup has issues with 25-1 (LG tuner possibly) but I can pull some Providence signals from 52 miles and 153 degrees. The HR10-250 cannot.

Wednesday I'll have a new Tivo HD S3 to add to the HR10-250 and LG. I'd like to receive the Boston content including WHDH moving to hi-vhf 7 at 121 degrees and also get the Providence at 153 without a rotor or amp if possible. The new antenna will be located where my 3lnb dish is now and I'll try to use the existing dish j-mount with a 10 ft extension that will clear the roofline by a few feet.

I'm looking for a less directionally sensitive antenna so I can get 121-153 degrees.

Antennas being considered.

Wineguard 7694P, 7695P, 7696P, 1080HD
AD DB2 or DB4
CM 4221 or 4228 (I'm guessing I'd want the older non HD versions)

Am I missing any options?

All recommendations appreciated. Thanks. TVFool attached.

Your goal includes several high vhf stations (7, 9, 11, 12 and 13). I definitely consider the Winegard 7695 or 7696. The DB-2, DB-4, and CM 4221 have limited high VHF capability. The CM 4228 HD has lower gain than the old 4228 but has better high VHF reception. IMO, the winegard is a better choice, given the spread between your desired stations.

Your goal includes several high vhf stations (7, 9, 11, 12 and 13). I definitely consider the Winegard 7695 or 7696. The DB-2, DB-4, and CM 4221 have limited high VHF capability. The CM 4228 HD has lower gain than the old 4228 but has better high VHF reception. IMO, the winegard is a better choice, given the spread between your desired stations.

Exactly what I was looking for. Thanks IDRick.

I'm looking at larger antennas and those with more power. I found a Winegard that is either a HD7010 or PR5646 with coverage to the Red Zone or UHF 30 miles and VHF 45 miles. Right around $40. Or, would the Winegard PR9032 Directional Yagi be better? It is ONLY UHF. Also there is a Winegard PR7013 or HD7015 and also an Antenna Craft HBU-22 or Channel Master CM2016. These are all about the same price and would fit in my attic or on the roof if needed. I'd like VHF/UHF/FM if possible.

After hooking everything up, I lost ABC on KOAT 7.1. Even on Analog, it has what looks like little diamonds falling down toward the bottom. I did NOT have that problem prior to connecting the CECB. I switched out the Tivax for the Zinwell 950A and it seems a little better, but Channel 7.1 has NO signal this evening on the CECB. I can still pull it in on the Digital Recorder, but it is not as clear as it was. I don't understand why...

Supposedly 7.1 has the highest signal of the channels I receive. It is at 109 degrees where all the rest I get are at 110. Could that be the problem? I can't see where 1 degree would make that much difference, but as I said before, I don't understand these signals anyway.

That's why I come here and ask a lot of questions!:p

Linda

I am a new poster so please forgive my little knowledge on the topic. I am located in rural Alabama, in a relatively low part of the landscape, and have an antenna question. I currently have a rooftop mounted directional old-style conventional antenna (do not know make, but I estimate it to be 15 to 20 yrs old) on a rotor with a Radio Shack mast mounted preamp. I used to have a Channel Master preamp- I switched it out and have seen little difference between the two; at least with regard to analog reception. The antenna feeds two tv’s; I have a splitter after the preamp. I have worked to ensure no other splitters or coupling in the cables.

The issue- There are three channels (networks) we are interested in receiving (I have attached my tv fool report); channel 15 (41 miles, 115 deg), channel 9 (41 miles, 115 deg), and channel 12 (58 miles, 227 deg). Through mast rotation, I can receive channel 15 (88% digital tuner strength) and channel 9 (35%) digitally, but not 12 (15 to 20%). Thus, my main issues are 9 (which is sporadic) and 12.

My basic questions- 1) do ya’ll think that investing in a newer antenna (e.g. DB8 etc…) could likely improve this situation, 2) is an omnidirectional even a possibility for functioning here (considering the spread of 115 vs 227 degrees), and 3) what looks to be my best option (or am I already doing it)?

Again, I am very appreciative of any response.

Are the stations you are trying to get WFSA and WTVM? Take a look at a pretransition TVFool report. It looks like they are now on channels 47 and 14. These are UHF channels and will come in best with a UHF antenna. Your antenna might be VHF only. Can you post the model or a picture? These channels will change their physical channel after the Analog shut off which will probably in June.
John

After hooking everything up, I lost ABC on KOAT 7.1. Even on Analog, it has what looks like little diamonds falling down toward the bottom. I did NOT have that problem prior to connecting the CECB. I switched out the Tivax for the Zinwell 950A and it seems a little better, but Channel 7.1 has NO signal this evening on the CECB. I can still pull it in on the Digital Recorder, but it is not as clear as it was. I don't understand why...

Supposedly 7.1 has the highest signal of the channels I receive. It is at 109 degrees where all the rest I get are at 110. Could that be the problem? I can't see where 1 degree would make that much difference, but as I said before, I don't understand these signals anyway.

That's why I come here and ask a lot of questions!:p

Linda
KOAT is a VHF station and at the bottom of the VHF high scale.
Do you have a VHF antenna?
I'm thinking no, and at 16 miles its possible that your UHF antenna was pulling it in.
Once you added the CECB it knocked a few db off your signal so it no longer comes in.
So if you don't have a VHF antenna get one, it should solve your problem.
At 16 miles rabbit ears may do the trick.

KOAT is a VHF station and at the bottom of the VHF high scale.
Do you have a VHF antenna?
I'm thinking no, and at 16 miles its possible that your UHF antenna was pulling it in.
Once you added the CECB it knocked a few db off your signal so it no longer comes in.
So if you don't have a VHF antenna get one, it should solve your problem.
At 16 miles rabbit ears may do the trick.

Yes, I have a combo Winegard Prostar 1000 model PR-7000 (replaced by the PR-7013) and according to the engineering specs, "Channel 7 has a 5 dB gain over reference dipole with a front-to-back ratio of 8.5dB." (whatever that means??:confused:) The only difference that I wonder about is that 7.1 is at 109 degrees whereas all the rest are coming through at 110 True Azimuth. 7.1 has a higher NM(dB) than 13 and I receive 13 very clearly.

All the transmitters for the channels I receive are 15.9 to 16.1 miles away all in the 109 to 110 degree range according to TV fool. dB is from NM(60.5 dB) to NM(dB 56.3) and power (dBm) from -30.4 to -34.6. 13.1 is transmitting at 75KW at 110 degrees and I get it fine. It will be going back to 13 also.

Fox on 2.1 has the highest KW power with 4.1, 5.1 and 7.1 from 180KW to 150KW. I get 4.1, 5.1 fine too. I even called the Engineer at 7.1 and asked him what they were doing differently in the past week. He said all is the same.

13.1 and 7.1 will be transmitting on vhf and channel 7.1 is my favorite station. I also have a great receiver that needs an FM antenna too. Someone recommended the Winegard 7694. Would that be better?

Actually, in looking at TVFool, channel 7 is the only one that is at 109 True Azimuth. All the others are at 110 and Magnetic North at 100-101. Could the True Azimuth be the problem? (I don't know anything about any of this except what I read.)

Linda

Are the stations you are trying to get WFSA and WTVM? Take a look at a pretransition TVFool report. It looks like they are now on channels 47 and 14. These are UHF channels and will come in best with a UHF antenna. Your antenna might be VHF only. Can you post the model or a picture? These channels will change their physical channel after the Analog shut off which will probably in June.
John

Yes, stations in question are WSFA (pre 14, post 12) and WTVM (47,9). Thus, they will be switching to VHF post transition. The station I receive the best digitally (WRBL, 15 pre and post) is UHF, so I assume my UHF reception is decent (maybe incorrectly?). I will check the antenna more closely for an exact model- but it is old, and I could find no legible markings (I'll also get a picture). It looks like post-transition, I will need VHF and UHF (9,12 and 15), with same constraints as discussed above. Any suggestions- and thanks so much-

We should be able to tell a lot about the antenna once the picture is posted. Do you get any other digital channels and how do analog channels from the markets that you want look?
John

Could the True Azimuth be the problem? (I don't know anything about any of this except what I read.)
Linda
Yes, The compass that you used to align the antenna points to magnetic north.
So if you pointed the antenna to 110 on the compass I would definitely go back and realign it to 100.
Hope this solves the issue.

With the British pound at historic lows, and some price reduction on the manufactures part, this low noise preamp is tempting me, more than ever. You can buy the package, with shipping, for about $160 US. My question is this, how much improvement can I expect from going from a 2dB noise factor to a .4 dB noise factor? Is it just the 1.6 dB, or is there more to it than that? Thanks, Walter

Actually, in looking at TVFool, channel 7 is the only one that is at 109 True Azimuth. All the others are at 110 and Magnetic North at 100-101. Could the True Azimuth be the problem? (I don't know anything about any of this except what I read.)
Linda,

I don't think the 1 degree is going to be the concern here. When the antenna was aimed, was a compass used to set to the "true" azimuth? If so, you'll be close to 10º off -- pointing closer to a true 120º.

When the antenna is actually pointing at a true 110º in your location, the compass will show it as about 101º (relative to *magnetic* north). If that's the case, then perhaps the antenna should be re-aimed with a compass reading of about 100º or 101º. That would point in a *true* azimuth of 110º.

With the British pound at historic lows, and some price reduction on the manufactures part, this low noise preamp is tempting me, more than ever. You can buy the package, with shipping, for about $160 US. My question is this, how much improvement can I expect from going from a 2dB noise factor to a .4 dB noise factor? Is it just the 1.6 dB, or is there more to it than that? Thanks, Walter

The answer is that it depends more on antenna noise than noise figure. Noise figure is not proportional to power but Deg. K is. The noise temperature of 0.4 dB is 28 deg. K and 2 dB 170 deg. That is a reduction in noise power of almost 8 dB. If you have enough preamp gain, low enough transmittion line loss and a good receiver frontend, the system noise temperature will be slightly higher than the sum of preamp noise power and antenna noise power. Without additional manmade noise an antenna pointed at the ground will pick up about 300 deg K and a high gain antenna pointed up will be 20 to 30 Deg. A guess of our antennas pointed at the horizon in an RF quite neighborhood is 150 Deg. This gives a system noise temp of 178 for the .4 dB preamp and 320 for the 2 dB preamp. This is about a 2.5 dB reduction in system noise. If you live in a noisy RF neighborhood and the antenna noise was 450 deg. you would only see a 1.5 dB system improvement with the better preamp. If either preamp goes into clipping its noise temperature can get to thousands of degrees causing reception to be non exsistant or seriously degraded.
I switched from an AP4700 to ResearchCom unit a weak digital station with a lot of dropouts improved to almost no dropouts. An snowy anlog station showed reduced snow but it was not eliminated.
John

The answer is that it depends more on antenna noise than noise figure. Noise figure is not proportional to power but Deg. K is. The noise temperature of 0.4 dB is 28 deg. K and 2 dB 170 deg. That is a reduction in noise power of almost 8 dB. If you have enough preamp gain, low enough transmittion line loss and a good receiver frontend, the system noise temperature will be slightly higher than the sum of preamp noise power and antenna noise power. Without additional manmade noise an antenna pointed at the ground will pick up about 300 deg K and a high gain antenna pointed up will be 20 to 30 Deg. A guess of our antennas pointed at the horizon in an RF quite neighborhood is 150 Deg. This gives a system noise temp of 178 for the .4 dB preamp and 320 for the 2 dB preamp. This is about a 2.5 dB reduction in system noise. If you live in a noisy RF neighborhood and the antenna noise was 450 deg. you would only see a 1.5 dB system improvement with the better preamp. If either preamp goes into clipping its noise temperature can get to thousands of degrees causing reception to be non exsistant or seriously degraded.
I switched from an AP4700 to ResearchCom unit a weak digital station with a lot of dropouts improved to almost no dropouts. An snowy anlog station showed reduced snow but it was not eliminated.
John

Thanks, John, Sounds like it might be worth a try. By the way, any ideas on why WSBE-PBS is so weak? I can get WNAC- FOX most of the time, this time of year, with no problems, but that PBS station, almost never. Thanks. Walter

It probably depends on where you live. Both WNAC and WSBE use directional antennas. I live is SE CT and the digital version of WSBE is considerably stronger than WNAC. See how they compare on TVFool. Here WSBE comes out 4 dB stronger in the prediction and in reality it is probably even stronger than that.
John

Linda,

I don't think the 1 degree is going to be the concern here. When the antenna was aimed, was a compass used to set to the "true" azimuth? If so, you'll be close to 10º off -- pointing closer to a true 120º.

When the antenna is actually pointing at a true 110º in your location, the compass will show it as about 101º (relative to *magnetic* north). If that's the case, then perhaps the antenna should be re-aimed with a compass reading of about 100º or 101º. That would point in a *true* azimuth of 110º.


That was so long ago (1994) that I don't remember.....:o I WILL use a compass this time though. I think I'm going to get a Medium Directional for Suburban distance for a little more power. I understand I lose about 30-40% by mounting it in the attic. And, I don't know how to figure all those dB's and dBi's.

The winds are sooooo strong here, that I don't want to put it on the roof, even though I know I'd get a better signal.;)

In hdtvprimer antenna chart, Winegard YA-1713 is depicted with a big Gain Loss across Ch13:
www.hdtvprimer.com/ANTENNAS/comparing.html
These results are based on Ken Nist's NEC simulation runs from several years ago....

The link at the top of that webpage leads to Ken Nist's w1713a.ez NEC file and ant.xls summary.
Neither of these depict a big Gain Loss across Ch13!!!!!

I have been trying to reproduce Ken Nist's results as well as calculate 4nec2 results for a
recently purchased YA-1713....which appears to have different element diameters and other
measurements than the one modeled by Ken Nist....perhaps there are two different models....
Furthermore, Nist assumed/found a better match to 300-ohm, whereas mine is 75-ohm.
Both 4nec2 files are attached below.

Can anyone verify their YA-1713 antenna measurements against either antenna???
Has anyone conducted any ON-AIR measurements???
Does anyone have problems with Analog Ch13???

Updated summary of NEC Simulation results can be found here:
http://imageevent.com/holl_ands/wgya1713

As described in the above link, I conducted an ON-AIR TEST with an RF attenuator to see if Analog
Ch13's audio/video dropped out any earlier than other Hi-VHF channels and whether Ch13's audio
dropped out early, in comparison to Ch13's video. All channels performed THE SAME.
Hence I concluded the Big Gain Loss across Ch13 was NOT FOUND in a 70-mile live test and must
be an artifact of the incomplete NEC Simulation process (still working on a more detailed model).

Hollands,

thanks for the great post! Along the same lines, would it be possible for you to show us how the YA-1713 compares to a Funke PSP.1922? I would love to see the two of them head to head, as I have owned both.

Bill

It probably depends on where you live. Both WNAC and WSBE use directional antennas. I live is SE CT and the digital version of WSBE is considerably stronger than WNAC. See how they compare on TVFool. Here WSBE comes out 4 dB stronger in the prediction and in reality it is probably even stronger than that.
John

John, I live in Westerly, real close to you. TVfool has WLWC at the same strength as WSBE and I can almost always get it without dropouts, but almost never can I get that PBS station. Do you think I am some how just out of range of were this signal is being directed? Walter

I'm not going up on my roof to measure my year-old YA-1713, nor can I compare it directly with another antenna, but I do have an anecdotal data point on using it to receive channel 13.

The station in question is WLOS in Asheville NC, which has its transmitter on top of a high mountain so I have LOS to it even though I'm 82 miles away. It's currently using analog 13 and digital 56, and will move digital to 13 (about 30 kW) after analog shutdown.

I was worried a bit about my future reception on digital 13 because of the reported deficiency of the YA-1713 on that channel, and because WLOS's digital service contour will shrink in my direction when they move from 56 to 13. Instead of being right on the service contour as I am now, I'll be several miles outside.

Two weeks ago, WLOS did a middle-of-the-night test in which they shut down both analog 13 and digital 56, and fired up digital 13 for about an hour. I was very pleased with the results, getting a good strong signal in the 90% ballpark on all my DTV tuners, pretty much in line with what I've been getting on 56 with my 91XG.

Analog 13 (178 kW) isn't quite as good as 7 (WSPA) which is stronger (265 kW) and closer (53 miles), but it's still pretty good, just a little bit of noise that isn't visible at normal viewing distance.

jtbell,

I'm not sure who to believe. The YA-1713 looks good according to the Winegard specs.(10.3 db gain over reference dipole). The HDTV primer shows quite a deficit at the right edge of frequency. How does channel 13 analog look to you? My analog channel 13 is a little snowy, but plagued with electrical interference from nearby power lines. My digital channel 13 will be @ only 9.8 kw-omni @ 40 miles. Not sure what to expect after the switch.

Anybody out there have much personal experience with channel 13 issues on the YA-1713? Is the Antennacraft noticably better?

Thanks, Glen

I was worried a bit about my future reception on digital 13 because of the reported deficiency of the YA-1713 on that channel, and because WLOS's digital service contour will shrink in my direction when they move from 56 to 13. Instead of being right on the service contour as I am now, I'll be several miles outside.

Two weeks ago, WLOS did a middle-of-the-night test in which they shut down both analog 13 and digital 56, and fired up digital 13 for about an hour. I was very pleased with the results, getting a good strong signal in the 90% ballpark on all my DTV tuners, pretty much in line with what I've been getting on 56 with my 91XG.

Here's another data point. I have a YA-1713 mounted outdoors, about 10 feet high just above the roof line and about 30" below a 91XG on the same mast. Our antennas are fixed at about 120º toward the main Austin cluster. The tower for KAKW (channel 62.1, digital RF 13) is 40 miles away at a direction of 92º.

With the antenna skewed almost 30º from the channel 13 transmitter and a distance of 40 hilly miles between us, with my tuner (a D* HR20-700) the signal regularly comes in at 90-95%.

God, I cannot wait to get my Funke psp.1922... Cannot wait to see what it does for my super weak area... I have a channel 9 and 11 at 78 miles, tropo on tvfool, with horrible terrain and a channel 13 from 86 miles also tropo on tvfool, but much more open for a few miles before hitting the hills and the station on 13 I am after, is a 2000ft tower.... I can measure and post the specs of the YA-1713, once I switch it out with the Funke....

Question I'm hoping someone can help me answer. What pre-amp should I add to my DB4 antenna?

I have DB4 UHF antenna mounted in my attic that does not have a preamp. I plan to connect it to an HD tuner that, according to the manual, doesn't have built in gain/amplification and requires an "amplified antenna" to receive off-air signals. (It's an ATI TV Wonder 650 HDTV tuner card for Media Center.) I've tested this statement and found it to be true. Without amplification, the tuner picks up very little. Hooked up to a friends amplified antenna it picked up all my stations clearly.

I'm only interested in main local channels and, according to the TVFool.com analysis of the stations in my area (attached,) all the main locals are located within 15 miles of me at ~70 degrees and all but one will be transmitting in UHF after the switch in Feb.

I was thinking the Channel Master 7777 or 7778, or the Winegard AP-8700. I've spent some time reading through the threads and have only confused myself further with discussions of overloading, separate VHF/UHF preamps versus combined, etc.

This HD tuner will be the only tuner connected to the antenna, but there is a remote possibility I will split it to two locations in the far future. Currently the tuner will be connected to the antenna via 70ft of RG6 cable.

Does anyone have a suggestion beyond the preamps I'm considering? Thanks for your help.

Question I'm hoping someone can help me answer. What pre-amp should I add to my DB4 antenna?

I have DB4 UHF antenna mounted in my attic that does not have a preamp. I plan to connect it to an HD tuner that, according to the manual, doesn't have built in gain/amplification and requires an "amplified antenna" to receive off-air signals. (It's an ATI TV Wonder 650 HDTV tuner card for Media Center.) I've tested this statement and found it to be true. Without amplification, the tuner picks up very little. Hooked up to a friends amplified antenna it picked up all my stations clearly.

I'm only interested in main local channels and, according to the TVFool.com analysis of the stations in my area (attached,) all the main locals are located within 15 miles of me at ~70 degrees and all but one will be transmitting in UHF after the switch in Feb.

I was thinking the Channel Master 7777 or 7778, or the Winegard AP-8700. I've spent some time reading through the threads and have only confused myself further with discussions of overloading, separate VHF/UHF preamps versus combined, etc.

This HD tuner will be the only tuner connected to the antenna, but there is a remote possibility I will split it to two locations in the far future. Currently the tuner will be connected to the antenna via 70ft of RG6 cable.

Does anyone have a suggestion beyond the preamps I'm considering? Thanks for your help.

Maybe a Winegard AP-8700, but to be safe, go with a Winegard HDP-269, that will be sure not to overload on your strong signals... Gut says that the 8700 would be fine....

Maybe a Winegard AP-8700, but to be safe, go with a Winegard HDP-269, that will be sure not to overload on your strong signals... Gut says that the 8700 would be fine....

Thanks gjvrieze. I'll take a look at the Winegard HDP-269. I keep falling into the mental trap that a little higher gain (18.7dB UHF gain on the 8700 vs. 12dB UHF gain for the HDP-269) would be better to overcome the loss from being an attic antenna, and the tuner not having any gain/amplification of its own.

What I'm having trouble understanding is where the dBmV comes into play, leading to possible overloading. It's more than 10dBmV higher on the HDP-269 (39dBmV UHF on the 8700 vs. 49.5dBmV UHF gain for the HDP-269.) Several posts by holl_ands prompted a lot of discussion about the topic, but I’m having some difficulty understanding how to use his spreadsheet.

I guess it’s just my obsessive nature, but I’m determined to better understand the whole topic.

How does channel 13 analog look to you?

Here are some samples from my YA-1713 by way of a DVD recorder (XP mode):

Channel 13 is 178 kW at 82 miles.

Channel 7 is 265 kW at 53 miles.

And just for fun, channel 4 is 100 kW at 60 miles (remember this is a high-VHF antenna). There's usually more impulse noise on this channel, but I was lucky this morning.

I have line of sight to all three transmitters.

If you already have the antenna try it without a preamp. You have a large number of huge signals and even if the tunner card is relatively deaf you should be able to receive OK. If you do try a preamp get the lowest gain one you can find, although it may overload anyway and an overloaded preamp is worse than no preamp.
You are showing a couple of VHF channels in your area. The DB 2 and 4 are designed only for UHF. One of the new combo VHF high/UHF antennas may be a better match for your location.
John


Question I'm hoping someone can help me answer. What pre-amp should I add to my DB4 antenna?

I have DB4 UHF antenna mounted in my attic that does not have a preamp. I plan to connect it to an HD tuner that, according to the manual, doesn't have built in gain/amplification and requires an "amplified antenna" to receive off-air signals. (It's an ATI TV Wonder 650 HDTV tuner card for Media Center.) I've tested this statement and found it to be true. Without amplification, the tuner picks up very little. Hooked up to a friends amplified antenna it picked up all my stations clearly.

I'm only interested in main local channels and, according to the TVFool.com analysis of the stations in my area (attached,) all the main locals are located within 15 miles of me at ~70 degrees and all but one will be transmitting in UHF after the switch in Feb.

I was thinking the Channel Master 7777 or 7778, or the Winegard AP-8700. I've spent some time reading through the threads and have only confused myself further with discussions of overloading, separate VHF/UHF preamps versus combined, etc.

This HD tuner will be the only tuner connected to the antenna, but there is a remote possibility I will split it to two locations in the far future. Currently the tuner will be connected to the antenna via 70ft of RG6 cable.

Does anyone have a suggestion beyond the preamps I'm considering? Thanks for your help.

I'm not sure who to believe. The YA-1713 looks good according to the Winegard specs.(10.3 db gain over reference dipole). The HDTV primer shows quite a deficit at the right edge of frequency.
Thats the thing, at what point does Winegard measure the channel 13 (or other channel) data, the beginning, middle or end ?

It sounds like everyone posting here so far are using later model YA-1713s. Its good to know channel 13 performance is better than the model shows. At VHF-HI frequencies, small changes in the build can skew the gain curve for the distance of 6 mhz (14%) on an antenna designed for 42 mhz bandwidth. Too bad there isnt a channel that goes from 216 mhz to 222 mhz or higher, so the real drop off point could be determined.

Channel 13 is 178 kW at 82 miles.

Channel 7 is 265 kW at 53 miles.

I have line of sight to all three transmitters.Wow, they look pretty good!! My channel 13 doesn't look nearly as good at only 40 miles with 316 kw. TV FOOL lists it as LOS now(was 2 edge a month ago), but my antenna is level with the ground only 1 street away. I'm basically pointing right into a gradual incline for about an 1/8th of a mile. For some reason TV FOOL doesn't seem accurate for my location anymore???

Anyone else noticed a change?

As requested, I have attached my pre and post-transition TV Fool Report and a picture of my current antenna. For background purposes: I am located in rural Alabama, in a relatively low part of the landscape. I currently have a rooftop mounted directional old-style conventional antenna (see picture) on a rotor with a Radio Shack mast mounted preamp. The antenna feeds two tv’s; I have a splitter after the preamp. I have worked to ensure no other splitters or coupling in the cables.

There are three channels (networks) we are interested in receiving; channel 15 (WRBL-41 miles, 115 deg), channel 9 (WTVM-41 miles, 115 deg), and channel 12 (WSFA-58 miles, 227 deg). Through mast rotation, I receive WRBL (88% digital tuner strength) and WTVM (35%, sporadic signal) digitally, but not WSFA (15 to 20%). WSFA is located in Montgomery (227 deg), WRBL and WTVM are in Columbus, GA (115 deg). Thus, the stations with problems are WSFA (pre 14, post 12) and WTVM (47,9). Post-transition, I will need VHF (WTVM and WSFA) and UHF (WRBL).

My questions: 1) will a new antenna (e.g. DB8 etc…) likely improve this situation significantly compared to what I have, 2) is an omnidirectional even a possibility for functioning here (considering the spread of 115 vs 227 degrees), and 3) any suggestions on which antenna I should obtain? Any information greatly appreciated.

As requested, I have attached my pre and post-transition TV Fool Report and a picture of my current antenna. For background purposes: I am located in rural Alabama, in a relatively low part of the landscape. I currently have a rooftop mounted directional old-style conventional antenna (see picture) on a rotor with a Radio Shack mast mounted preamp. The antenna feeds two tv’s; I have a splitter after the preamp. I have worked to ensure no other splitters or coupling in the cables.

There are three channels (networks) we are interested in receiving; channel 15 (WRBL-41 miles, 115 deg), channel 9 (WTVM-41 miles, 115 deg), and channel 12 (WSFA-58 miles, 227 deg). Through mast rotation, I receive WRBL (88% digital tuner strength) and WTVM (35%, sporadic signal) digitally, but not WSFA (15 to 20%). WSFA is located in Montgomery (227 deg), WRBL and WTVM are in Columbus, GA (115 deg). Thus, the stations with problems are WSFA (pre 14, post 12) and WTVM (47,9). Post-transition, I will need VHF (WTVM and WSFA) and UHF (WRBL).

My questions: 1) will a new antenna (e.g. DB8 etc…) likely improve this situation significantly compared to what I have, 2) is an omnidirectional even a possibility for functioning here (considering the spread of 115 vs 227 degrees), and 3) any suggestions on which antenna I should obtain? Any information greatly appreciated.

First, your antenna is a small-mid range antenna, not a deep fringe, which is needed... No omni will work with signals that are as low as yours... I would say go with a 91XG mounted 4ft over a YA-1713, with a CM7777 amp, but I am little worried about WELL-FM (60kW) and WSTH-FM (86kW) being somewhere between 8-12 miles from you... Could you post your fmfool results as well... With the setup, I described, you could get all of the stations in the red, prolly with ease....(just need to check the signals on FM, to make sure a 7777 would not overload...)

First, your antenna is a small-mid range antenna, not a deep fringe, which is needed... No omni will work with signals that are as low as yours... I would say go with a 91XG mounted 4ft over a YA-1713, with a CM7777 amp, but I am little worried about WELL-FM (60kW) and WSTH-FM (86kW) being somewhere between 8-12 miles from you... Could you post your fmfool results as well... With the setup, I described, you could get all of the stations in the red, prolly with ease....(just need to check the signals on FM, to make sure a 7777 would not overload...)

Thanks for the quick advice. Question, considering WRBL (post-transition 15) will be the only UHF station of interest, and I receive it with my current set up at 88-90% signal strength (it's my best channel), do you think I would be able to get by with just the YA-1713 (and still get this UHF station) on a rotating mast with preamp (CM7777 or similar). I understand this antenna is good for high end VHF (which will be good for 9 and 12) , but I read it has some UHF capacity? Any advice greatly appreciated-

Hollands,

thanks for the great post! Along the same lines, would it be possible for you to show us how the YA-1713 compares to a Funke PSP.1922? I would love to see the two of them head to head, as I have owned both.

Bill
I can't even "see" it....Funke changed their website...and only lists a couple antennas!!!!

If you are asking if I could model it, I would need precise measurements and photos.

gjvrieze,

Any chance of you taking some measurements before you mount yours????

Mine are 43' up!

Bill

By the way, here is a link for the original specs page:

http://www.funke.nl/library/1190_098502_psp1922_051203_790500985.pdf?PHPSESSID=5d4a8e9e5 10fc10921e3962619c17526

Thanks for the quick advice. Question, considering WRBL (post-transition 15) will be the only UHF station of interest, and I receive it with my current set up at 88-90% signal strength (it's my best channel), do you think I would be able to get by with just the YA-1713 (and still get this UHF station) on a rotating mast with preamp (CM7777 or similar). I understand this antenna is good for high end VHF (which will be good for 9 and 12) , but I read it has some UHF capacity? Any advice greatly appreciated-

No way that the YA-1713 would get WRBL, that signal is not that strong (and the VHF to UHF HUGE loss!), if you want to keep the price down a bit, get a YA-1713 for VHF and use your old antenna for UHF, separated by the CM7777 amp which takes a separate VHF and UHF antennas or a combined.... You could even aim the separate antennas in different directions, if that would help cut down on the amount of rotoring that you have to do... (would make using the rotator control weird, as one antenna would line up with what it shows and other would be xxx degrees off)
Channels 7,9, and 12 are weak enough, they need some good measures to get reliably....

I can't even "see" it....Funke changed their website...and only lists a couple antennas!!!!

If you are asking if I could model it, I would need precise measurements and photos.

gjvrieze,

Any chance of you taking some measurements before you mount yours????

Mine are 43' up!

Bill

By the way, here is a link for the original specs page:

http://www.funke.nl/library/1190_098502_psp1922_051203_790500985.pdf?PHPSESSID=5d4a8e9e5 10fc10921e3962619c17526

Yes, I will get tons of pictures and measurements indoors first.. It is winter here in MN, and I need to find the correct safety belt before installing it:)

Well, guys, my moment of truth has arrived. Here are my measurements of digital and analog signals using both a digital and an analog signal level meter (SLM).

Because my wife and my friends were VERY generous to me at Christmas, I am now able to compare readings from my Sadelco 719E with readings from a DisplayMax 800.

http://i496.photobucket.com/albums/rr328/rabbit73_photos/IMG_0144_1_1.jpg

I wanted to do this before the transition while I still had a good selection of digital and analog signals coming from Norfolk. I picked 6 signals, 3 digital and 3 analog. The virtual number indicates digital. The measurements, including the ones for CH13, were made using a CM4221 antenna. I used a splitter to make simultaneous readings on both meters because OTA signals don't stay at the same level.

Channel 719E 800
dBmV dBmV
13 -9.5 -11.4
16(15.1) -0.5 +2.9
27 +6.8 +4.5
31(10.1) -0.5 +1.2
43 +9.5 +7.6
50(27.1) -2.8 -2.3
And as a chart:
http://i496.photobucket.com/albums/rr328/rabbit73_photos/2SLMsforAVS.png
...you can use an inexpensive analog signal meter and add 8dB to whatever it says the signal level is. I often use a Leader LF941 analog signal meter with a digital display when working on digital antenna reception because it weighs less than my other meters. You can get an analog (NTSC) signal meter...with a digital readout for $200 or less. You can even do the job with a clunker with a rotary dial and a needle meter for maybe $10 to $30.

On the other hand, if someone wants to use a meter to aid in developing quality antenna reception in a poor reception environment with multipath, the signal strength measurement, which just becomes an extrapolation of the signal level at and around 1.25 MHz above the lower channel band edge, does not show the signal quality the way that a spectrum analyzer can. If you are getting nailed by multipath, the waveform will usually have a big notch in it, whereas if it is pure, it will be a level plateau.

The chart gives me the corrections needed to make correct readings of digital signals with my analog signal SLM, but I'm really not too concerned about corrections because I mostly use my SLM for comparative readings to aim antennas, compare antennas, and find the "hot spot" location for an antenna. These comparisons rely on the the linearity of my meter which is easy to check by inserting a 20dB attenuator to see if the reading drops by 20dB.

The corrections are the result of differences in the calibration of the SLMs, the tolerance allowed for each SLM, and the fact that analog signals are measured with a peak value of the video and sound carriers and digital signals are measured with an average value across most of the 6MHz channel. Sadelco says in the manual that two 800 meters can differ by as much as 2dB and still be in spec.

My 719E is reading too high on digital and analog signals because it is off calibration on both. If it were on calibration the red line would be lower all across the chart, its readings of analog signals would be the same as the 800 readings, and its readings of digital signals would be a lot lower. This would make it necessary to add a positive correction to the 719E reading for digital signals, which is what it is supposed to be. It was just a matter of luck that both meters were fairly close together.

The engineers at Potomac Instruments seem to think it's OK to measure digital signals with an analog signal meter if the proper corrections are applied: http://www.pi-usa.com/pdf/dtva.pdf

Highdefjeff seems to think it's OK to use an analog signal meter to measure digital signals (He is talking about digital signals coming from a satellite, but the digital signals coming from a terrestrial transmitting tower are similar). To quote him:
Here I am in the digital world suggesting that you use an "older" analog type meter. Sounds wrong, doesn't it? It's not. Let me explain "why?" starting with a little background.

What If I asked you "Why are you using a digital meter to read an analog signal?" Many of you would say I'm full of "it", or I couldn't be talking about satellite signal. But, I am talking about satellite signal, the signal at the "front end" that you measure is analog. That's another story, and you can read about it: www.designlinenetwork.com (http://newsletter.designlinenetwork.com/cgi-bin4/DM/y/nBH6t0OQ2OT0QTC0FoXc0Eq)
http://www.wowvision.tv/signal%20meters.htm
http://www.wowvision.tv/signal_strength_meters_BER.htm
http://www.wowvision.tv/HDglossary.htm
http://www.wowvision.tv / (http://www.wowvision.tv/) Home

To anyone who thinks that an analog SLM couldn't possibly be of any use for digital signals I say: Try it for yourself first.

Interesting that the 800 gave higher readings than the 719E did on the digital encoded signals (average value) and lower readings on the analog signals (peak value).

The 2db difference with analog is understandable, what I don't understand is the lack of difference between meters with a digital signal.
FWIW, I never stated that a analog meter couldn't be used for digital, only that the readings won't be correct because of the way it measures those signals.

The readings of the digital signals with the 800 are supposed to be higher than the readings with the 719E. This is because digital makes more efficient use of the 6MHz bandwidth and is why digital transmitters can use less power for the same coverage area. The broadcasters are looking forward to lower electric bills, and the back-up generators can be smaller.

Take a look at pp 1-4 of Analyzing the Signal Quality of NTSC and ATSC Television RF Signals:http://www.sencore.com/uploads/files/Analyzing_Signal_Quality_of_TV_RF_Signals.pdf

And look at the spectrum analyzer displays of NTSC & ATSC signals in fig. 6 & 7 of:
http://www.popular-communications.com/23-AntennasWeb92708.pdf

The readings of the digital signals with the 800 are supposed to be higher than the readings with the 719E.But, on average they are only 2db higher, not 8-15 which I and others have reported.My 719E is reading too high on digital and analog signalsAnd that would bring the difference to around 4db instead of 2.
I will do another comparision between my two digital SLM's and my analog meter and will post back. The orginal comparision was with another digital DLM which wasn't mine. That was where I saw the 8-15db difference that I also read shortly after I did the compairison.

That last quote wasn't meant towards you. It was meant to anyone that might suggest I said otherwise. ;)

What confuses the issue is that we have learned that the output voltage of a simple diode peak detector is higher than one designed for average or RMS. This leads us to the wrong conclusion about NTSC vs ATSC signals because we are measuring power (which is what dB is all about), not voltage and it doesn't take into consideration bandwidth or the efficiency of different modulation systems. Hams know that SSB(SC) is much more efficient than AM. With PSK31 you work the world very near the noise level with only 20 watts.

If I still don't have it right, I defer to holl_ands, who can give a much better explanation.

I recorded the readings as I saw them. It's not good science to "fudge" the figures. This is a Science forum, isn't it?

You are perfectly free to draw your own conclusions based on the data that I have presented. Or, better yet, you can run your own test with your own equipment, and post the results here.

As far as I'm concerned, this test proves that an analog SLM can be very useful when dealing with digital signals, which is what I set out to prove. Or, as my math teacher used to say, QED.

I think one possible problem or issue, is what the sampling width is set for with a digital SLM. On my Tektronix RFM151, I can change it to whatever I want. Tek. states "the channel edge should be one half of the channel width" which makes it the full 6MHz. Anaolg is set for -1.25 MHz and digital itn would be set for -3 MHz.

What I now question is how the pilot affects the overall level. For QAM, it doesn't matter, since there is no pilot, but for 8VSB there is. If a meter that is set for a slightly narrower width to exclude the pilot, I would assume it would affect the reading. I would further assume it would be lower than another meter set for the full width.

I apologize if this topic has been discussed.

I have been using with my Insignia CECB (to analog tv's and vcrs) antennas that consist of either a separate UHF antenna or a VHF antenna. With the exception of reception in one room, I am able to receive the broadcast of every major station (I live in the suburbs of a large metro area, on the middle floor of a multilevel apt. building.) I do have to ensure that the antennas are positioned exactly to avoid signal dropout or pixillation. My UHF antennas consist of an unamplified Radio Shack grid-type structure I bought years ago, also have a loop for another tv. The VHF antennas simply consist of pull out full length rabbit ear dipoles, easy to reposition.

I thought that since transmission of digital signals is UHF related, that a VHF antenna wouldn't be effective, but I have not found that to be the case.

Would the Zenith ZHDTV1Z antenna be overkill for my use? I don't have HDTV television sets, and the sets are all more than 5 years old. I am looking at getting a stronger antenna if I find that I am getting too many signal dropouts. (Also, when I begin using my Zinwell CECB 950-A which allows for station changing for recording, I may need a better overall antenna to pick up stronger signals given that the antenna will be one position for this recording when I am away.)

So, to summarize, I have found that the use of EITHER, a separate dipole rabbit ears, or, a separate stand alone UHF antenna, has been sufficient if receiving both VHF and UHF stations with the use of the Insignia CECB. How can this be given the discussion of needing both VHF and UHF antennas?

I thought that since transmission of digital signals is UHF related, that a VHF antenna wouldn't be effective, but I have not found that to be the case.

Basically, UHF antennas are optimzed for UHF reception and VHF antennas are optimized for VHF reception, but there is some crossover. With the upcoming DTV transition, many cities will have UHF only, but some cities will still have both UHF and VHF.

Would the Zenith ZHDTV1Z antenna be overkill for my use?

It certainly wouldn't be overkill, but it may or may not be the antenna for you. The first thing I would suggest is to checkout AntennaWeb (http://www.antennaweb.org)and TVFool (http://www.tvfool.com). Both of these web sites will show you what stations are available in your area, how far they are from you, and whether they are UHF or VHF. This is very useful information and should assist you in choosing and aiming your antennas.

So, to summarize, I have found that the use of EITHER, a separate dipole rabbit ears, or, a separate stand alone UHF antenna, has been sufficient if receiving both VHF and UHF stations with the use of the Insignia CECB. How can this be given the discussion of needing both VHF and UHF antennas?

In reference to your other questions, please checkout the following thread which is dedicated to indoor antennas and should answer a lot of questions.

EV's Best Top Rated HDTV Indoor Antenna Review Test Round-Up Guide (http://www.avsforum.com/avs-vb/showthread.php?t=1037779)

I have been having drop outs on 7.1 digital and Analog 7 has a lot of pixilation. Now I am starting to get dropouts on other channels too. It is not too bad during the day, but the evening is miserable.

But....I just noticed something else about 7.1! My Mitsubishi that is hooked up with red, white, yellow connecters to an AV modulator then to a Panny DMR EZ475 gets 7.1 just fine! It also receives analog channel 7 with no problem. I tried looking for a signal, but the DMR won't display it due to the single RF on the Mits.

Now, I wonder if 7 and 7.1 are having problems due to something touching??? Due to converter boxes? Due to a bad connector???? This is the Panasonic TV that is hooked up to a Zinwell ZAT-950A, a Panny DMR-EZ48V, a Dish 501PVR and a Yamaha V663 Receiver. The Tivax STB-T8 wouldn't keep 7.1 at all and Channel 7.1 is broadcasting at 280W and is only 16 miles from my home.

I should get my new Winegard HD7694 antenna Thursday or Friday and will hook it up Saturday, and I will also recheck my connections on my Panasonic TV to see if something is loose or missing or something. Looks like it may NOT be the antenna strength....Oh Well, I wanted to spend some money anyway......LOL:p

gjvrieze,

Here is the low power analog WEAU with the Funke at 112 miles.

http://webpages.charter.net/willscarlett/WEAU%20low%20power.jpg

This is actually watchable. I think it looks worse because I am so close to the TV. The sound is perfectly clear and in stereo.

Bill

gjvrieze,

Here is the low power analog WEAU with the Funke at 112 miles.

http://webpages.charter.net/willscarlett/WEAU%20low%20power.jpg

This is actually watchable. I think it looks worse because I am so close to the TV. The sound is perfectly clear and in stereo.

Bill
Wow that is better then my YA-1713 showed when WEAU-TV was full power...

rabbit73,

Id be interested in seeing a comparison analysis of your new digital meter compared to the two signal meters on your Apex DT502 CECB.

I'm interested too, and am working on that.

Good man !

It seems logical to me that in some future CECB or tuners, that they might include the digital waveform display in with the tuners signal meter. All the hardware (the display etc) is there as well as the digital info coming in over the air. Or am I just dreaming, heh. Or like on cars, they prefer to keep giving us just idiot lights, heh.

maybe it's already possible with secret key combinations or some hacks

Good man !

It seems logical to me that in some future CECB or tuners, that they might include the digital waveform display in with the tuners signal meter. All the hardware (the display etc) is there as well as the digital info coming in over the air. Or am I just dreaming, heh. Or like on cars, they prefer to keep giving us just idiot lights, heh.

Every piece they DONT include saves them money over production of say 1 million units...if a part cost 50 cents that would cost them 500K in profit....
Hardware may be there but it will take hacking to be able to use it (too bad they just cant provide some jack with the signal present.....but again, 10-25cents on the jack and the engineering mods to the PC board?? There goes, ah, profit (straight to China)!

I have been having drop outs on 7.1 digital and Analog 7 has a lot of pixilation. Now I am starting to get dropouts on other channels too. It is not too bad during the day, but the evening is miserable.

Curious....how do you get pixelation on an ANALOG channel??? (unless its in their digital STL or sat/network rcvr!)

Basically, UHF antennas are optimzed for UHF reception and VHF antennas are optimized for VHF reception, but there is some crossover. With the upcoming DTV transition, many cities will have UHF only, but some cities will still have both UHF and VHF.

In Texas and La, it will be a mix of V and U in most markets....those that are High Vs are flash cutting or returning to them....I would not say many or most will be UHF only....

Hardware may be there but it will take hacking to be able to use it (too bad they just cant provide some jack with the signal present.....but again, 10-25cents on the jack and the engineering mods to the PC board?? There goes, ah, profit (straight to China)!

I know. But look at all the useless extras and options found on typical consumer electronics. It would be nice for a change to include something half way useful. Or maybe theyre paid not to ????

Just like in the case of those cheap portable dvd players with the 7 inch LCD screens. Would it have killed them to include an NTSC tuner in them and charged maybe $10 more ? 5 inch CRT TVs with the tuners sold for $10 on sale. I know NTSC is doomed, but originally when the dvd players came out cheap, there was still a couple of years left. /end rant, heh/

Could someone recommend a good indoor antenna for me? I'm ditching my cable and going back to OTA. Here's my chart:

http://www.thejokell.com/avs/Radar-Digital2.png

I'm in a townhouse but the antenna will be on the first floor. There are apartments behind me (3 stories) and trees all around. I already have an RCA ANT537 and a Winegard Sharpshooter 3000, neither of which seem to do the job very well.

Any help? Thanks!

Theres a thread on this forum that has tons of indoor antenna comparisons. The Radio Shack $3.99 classic bowtie is a pretty high ranking one, heh.

Could someone recommend a good indoor antenna for me? I'm ditching my cable and going back to OTA. Here's my chart:

<snipped image>

I'm in a townhouse but the antenna will be on the first floor. There are apartments behind me (3 stories) and trees all around. I already have an RCA ANT537 and a Winegard Sharpshooter 3000, neither of which seem to do the job very well.

Any help? Thanks!Hmm, looks like the antenna farm is west of northwest of you...what is between you and the farm? The three story apartments? The tvfool results indicate that you should be getting very good reception...unless, of course, you have something blocking the signals. Elevation and height is your friend...if you could snake some coax cable up to an upstairs location. For a simple experiment you could run some coax up the stairs to the 2nd floor and try your existing antennas to see if the extra height helps. Also, be sure that the channel scan that you're doing is for OTA channels.

An outdoor 4-bay CM4421 wouldn't be *too* big...not exactly designer art, but could be concealed in a closet or either "boxed" artistically.

Best wishes,
Ed

I have decided to purchase a CM4228-HD for my second antenna, as it seems to have the highest gain on UHF channels 14-20 of any other antenna... and the two stations I want from that direction are 15 and 17. I have a digital 18 that would come from the backside, it's 1edge and 28 miles away, no LOS, Noise margin +32.6 ... do you think I will have to worry about adjacent channel interference on 17? And if so, is there some physical barrier one can install to keep signal coming in the backside down to a minimum?

Could someone recommend a good indoor antenna for me? I'm ditching my cable and going back to OTA. Here's my chart:

http://www.thejokell.com/avs/Radar-Digital2.png

I'm in a townhouse but the antenna will be on the first floor. There are apartments behind me (3 stories) and trees all around. I already have an RCA ANT537 and a Winegard Sharpshooter 3000, neither of which seem to do the job very well.

Any help? Thanks!
You have very high signal levels that are no doubt bouncing back and forth
between your surrounding buildings, creating serious multipath.

SS-3000 Sharpshooter should be fairly good at suppressing multipath from
one or two directions, but you are surrounded.....

Unless you are using a new 6th Gen tuner chip (e.g. CECB coupon converter)
the remaining multipath may be more than your DTV can overcome.

SS-3000 also has a high tolerance of strong signal levels, but the built-in
Preamp may still be overloaded.

RCA 537 has a built-in, very high gain Preamp that is readily overloaded.

First try a good NON-amplified antenna....and if no-go, back to cable...

Hmm, looks like the antenna farm is west of northwest of you...what is between you and the farm? The three story apartments? The tvfool results indicate that you should be getting very good reception...unless, of course, you have something blocking the signals. Elevation and height is your friend...if you could snake some coax cable up to an upstairs location. For a simple experiment you could run some coax up the stairs to the 2nd floor and try your existing antennas to see if the extra height helps. Also, be sure that the channel scan that you're doing is for OTA channels.

An outdoor 4-bay CM4421 wouldn't be *too* big...not exactly designer art, but could be concealed in a closet or either "boxed" artistically.

Best wishes,
Ed
Winegard HD-4400 has more WAF for indoor use than CM4221:
http://www.solidsignal.com/prod_display.asp?prod=HD-4400&main_cat=03&source=googleps

I have decided to purchase a CM4228-HD for my second antenna, as it seems to have the highest gain on UHF channels 14-20 of any other antenna... and the two stations I want from that direction are 15 and 17. I have a digital 18 that would come from the backside, it's 1edge and 28 miles away, no LOS, Noise margin +32.6 ... do you think I will have to worry about adjacent channel interference on 17? And if so, is there some physical barrier one can install to keep signal coming in the backside down to a minimum?

There are several antennas that have more gain from 14 to 20 than the CM4228-HD

You have very high signal levels that are no doubt bouncing back and forth
between your surrounding buildings, creating serious multipath.

SS-3000 Sharpshooter should be fairly good at suppressing multipath from
one or two directions, but you are surrounded.....

Unless you are using a new 6th Gen tuner chip (e.g. CECB coupon converter)
the remaining multipath may be more than your DTV can overcome.

SS-3000 also has a high tolerance of strong signal levels, but the built-in
Preamp may still be overloaded.

RCA 537 has a built-in, very high gain Preamp that is readily overloaded.

First try a good NON-amplified antenna....and if no-go, back to cable...How about a directional antenna pointed toward the main strong stations, which would reduce the off axis strong signals, with some attenuators inline before the receiver, to reduce the really strong main signals?

I'm in a townhouse but the antenna will be on the first floor.

Is that really necessary? Even a simple single bowtie on the top floor of the house, facing the towers, especially through a window, will likely work better for UHF than anything you can set up on the first floor.

Otherwise, check out the indoor antenna thread. Reject anything amplified. A reflector on the UHF element will be helpful. For VHF, there's not much indoor which does better than rabbit ears, because of space issues.

Is that really necessary? Even a simple single bowtie on the top floor of the house, facing the towers, especially through a window, will likely work better for UHF than anything you can set up on the first floor.

Otherwise, check out the indoor antenna thread. Reject anything amplified. A reflector on the UHF element will be helpful. For VHF, there's not much indoor which does better than rabbit ears, because of space issues.

Well I rent and can't run new wires. And I don't really want a coax cable coming down loose from the second story.

So far I've only tried amplified solutions - I'll look into unamplified ones.

There are several antennas that have more gain from 14 to 20 than the CM4228-HD

There's only one that I can think of that is readily available and that would be the Triax Unix 100A. It's a little pricey after paying overseas shipping but worth it IMO if that's what you need.

http://cpc.farnell.com/jsp/level5/module.jsp?moduleId=cpc/253254.xml

There's only one that I can think of that is readily available and that would be the Triax Unix 100A. It's a little pricey after paying overseas shipping but worth it IMO if that's what you need.

http://cpc.farnell.com/jsp/level5/module.jsp?moduleId=cpc/253254.xml

The specs that I can find for the CM4228-HD is RF14 - 11.2db, RF19 - 11.6db
The Winegard PR9018, 9022 & 9032 have higher gain from RF 14 to 20 @ 13.3db to 14.9db...HD7084P, HD8200P, HD9095P, PR7052, HD7697P & HD7698P...ALL of these have higher gain from RF 14 to 20...Have you not seen any of these?

There are several antennas that have more gain from 14 to 20 than the CM4228-HD

According to these measurements, the Winegard PR-8800 is the winner.

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

The specs that I can find for the CM4228-HD is RF14 - 11.2db, RF19 - 11.6db
The Winegard PR9018, 9022 & 9032 have higher gain from RF 14 to 20 @ 13.3db to 14.9db...HD7084P, HD8200P, HD9095P, PR7052, HD7697P & HD7698P...ALL of these have higher gain from RF 14 to 20...Have you not seen any of these?

Where have you seen data on the new 4228HD?

Where have you seen data on the new 4228HD?

Right here:

http://www.digitalhome.ca/forum/showthread.php?t=95467&page=5

According to these measurements, the Winegard PR-8800 is the winner.

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

That PR-8800 has a nice flat curve.

According to these measurements, the Winegard PR-8800 is the winner.

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

According to that HDTVprimer comparison chart, the Winegard pr-9032 has a gain at channel 14 of 10db... the technical specs at solid signal's website give the gain for that model at channel 14 at 14.9 db.... which one is telling the truth?

According to that HDTVprimer comparison chart, the Winegard pr-9032 has a gain at channel 14 of 10db... the technical specs at solid signal's website give the gain for that model at channel 14 at 14.9 db.... which one is telling the truth?

Depends on what they are comparing it with....10db vs WHAT???? there SHOULD be an i or d after the db.....dbi is referenced to an non existant, theoretical antenna that radiates equally in all directions (doesnt exist in real life)....dbd references to a 1/2wave dipole which radiates in a figure 8 pattern broadside and around the dipole itself...
Any else (db) can be reference to a piece of spaghetti as far as we know....
unless the gain figures show dbi (which is 2.15db higher than dbd) or dbd, you cannot really take the figures given as fact!

According to Winegard's website, the pr-9032's gain at channel 14 over a referenced dipole is 14.9. According to the HDTVprimer chart, the pr-9032's gain at channel 14 is 10dbi, or 8 dbd. I'm like.... WTF?