This site is about the only site I've seen that shows the 4221, DB4, and others.

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

If two antennas look alike, then they will perform alike. Polar plots are more useful in helping you determine that one type of antenna is better for your situation than is another.

I have yet to build my HTPC w/ the HD tuners, and before I do, I want to ensure that I'm going to pick up the local HD channels. I thought the question I have might apply to more than just my area, so I'm not posting in my specific locale (I live in Tucson, AZ).

All/most of the local VHF SD channels and the UHF HD channels are broadcast from a local mountain about 20 miles from my home. My indoor antenna is picking up the VHF channels without a problem. Is it safe to assume that if I'm getting the VHF signals indoors from that location that I'll get the UHF signals from the same location?

If two antennas look alike, then they will perform alike.

I am so glad someone finally said that...

Well, I figured out the problem. He and I both miss-read the box, and his TV does NOT have an HDTV tuner.

Is there any Antennas that have a tuner, or even a separate tuner, he could consider?

For a general question, the general answer is 'go to antennaweb.org'.

If you get the VHF indoors, then you should be able to get UHF, but will never know till you try.

I have yet to build my HTPC w/ the HD tuners, and before I do, I want to ensure that I'm going to pick up the local HD channels. I thought the question I have might apply to more than just my area, so I'm not posting in my specific locale (I live in Tucson, AZ).

All/most of the local VHF SD channels and the UHF HD channels are broadcast from a local mountain about 20 miles from my home. My indoor antenna is picking up the VHF channels without a problem. Is it safe to assume that if I'm getting the VHF signals indoors from that location that I'll get the UHF signals from the same location?

Well, I figured out the problem. He and I both miss-read the box, and his TV does NOT have an HDTV tuner.

Is there any Antennas that have a tuner, or even a separate tuner, he could consider? Looks like your "cheap" friend is going to have to shell out some more bucks for a separate, standalone, over-the-air set-top digital HD tuner. (There is no such thing as an antenna with a built-in tuner. It's either built-in to the set or has to be added externally. He either has to rent one along with paid satellite/cable service or buy outright a separate tuner of his own from a manufacturer for OTA reception. Welcome to the Catch-22 world of HDTV.

Thanks. I know the 4221 is good - I have one on my roof. :) What I'm looking for is some hard data on the DB4, preferrably side-by-side tests with 4221 or similar. One guy in our local HD reception forum says the DB4 is junk and I just don't believe it. I can see how the construction might not be as good but the performance should be nearly identical to the 4221.

I think the problem is that the DB-4 may not be as durable, doesn't perform any better, and costs twice as much. Most Terk antennas work. We bust on them because they cost 3x antennas that work better.

For the price of a DB-4, you can get the CM4228, which is at least twice as good.

Well, I figured out the problem. He and I both miss-read the box, and his TV does NOT have an HDTV tuner.

Is there any Antennas that have a tuner, or even a separate tuner, he could consider?

Look here: http://www.avsforum.com/avs-vb/showthread.php?t=179095

Especially the part labeled "Over The Air DTV/HDTV"

I have yet to build my HTPC w/ the HD tuners, and before I do, I want to ensure that I'm going to pick up the local HD channels. I thought the question I have might apply to more than just my area, so I'm not posting in my specific locale (I live in Tucson, AZ).

All/most of the local VHF SD channels and the UHF HD channels are broadcast from a local mountain about 20 miles from my home. My indoor antenna is picking up the VHF channels without a problem. Is it safe to assume that if I'm getting the VHF signals indoors from that location that I'll get the UHF signals from the same location?
No, UHF has much higher propagation loss than VHF, may be lower in trasmitted power and suffers from much more diffraction loss, building loss (for indoor antennas) and esp. multipath effects.

First start by punching in your location at www.antennaweb.org.
You'll quickly see that Tucson has TWO very different antenna tower locations.
Most of the digital stations are on the same towers as their analog counterparts.
However, note that VHF analog CBS & UPN are on one, and their UHF Digital counterparts are on the other.

I think the problem is that the DB-4 may not be as durable, doesn't perform any better, and costs twice as much. Most Terk antennas work. We bust on them because they cost 3x antennas that work better.

For the price of a DB-4, you can get the CM4228, which is at least twice as good.

The phrase "may not be as durable" is based on what? I agree it is overpriced but most AntennasDirect stuff gets high marks for quality. Does anyone have first-hand knowledge of the DB4's quality?

I recently upgraded my 25 yr. old RS 160 " vhf/uhf on a 30' tower /w rotor. I used the following:
CM 4228 UHF
Wade VIP-306 VHF
CM 7777 Titan pre-amp
CM 9521A rotor/controller
All new RG-6 coax/ rotor wiring

I now get all Cleveland HD stations with no drop-offs and 92-98 Signal strength. Live about 45 miles south of Parma Farm. Below are some pics.

I like your set-up! I just purchased my Wade VIP-307SR. I did not put up the CM 4228, due to its inability to have a tight back door. Instead, went with the Winegard PR-9032. Lastly, tried both the CM 7777 and the Winegard AP2870, and had an improved picture withe the Winegard. This is because of the higher threshold in input capabilites.

On another note, in comparing the PR-9032 to the 91XG, the 91XG looks like a fraile piece of crap. The constuction of that thing is just piss poor!

No, UHF has much higher propagation loss than VHF.....
There is no additional propagation loss with increased frequency. Electromagnetic waves of all frequencies travel through free space with equal loss per unit of distance. The 20 log (Fo in MHz) term in the equation:

Free Space Loss = 36.58 dB + 20 log (Fo in MHz) + 20 log (Dtr in miles)

is really isotropic (0 dBi) antenna aperture versus frequency.

Ron

I like your set-up! I just purchased my Wade VIP-307SR. I did not put up the CM 4228, due to its inability to have a tight back door. Instead, went with the Winegard PR-9032. Lastly, tried both the CM 7777 and the Winegard AP2870, and had an improved picture withe the Winegard. This is because of the higher threshold in input capabilites.

On another note, in comparing the PR-9032 to the 91XG, the 91XG looks like a fraile piece of crap. The constuction of that thing is just piss poor!

Sounds like Winegard works for you.

I think if you'll check the specs the 4228 has comparable f/b ratio to the 9032. Directivity is probably even higher. The main drawbacks are weight, windload, and difficulty with stacking.

On another note, in comparing the PR-9032 to the 91XG, the 91XG looks like a fraile piece of crap. The constuction of that thing is just piss poor!

Yes, yes. We hear this all the time. But mine is still holding together and I haven't heard of anyone having problems with them.

It seems that everybody looks at this thing and says, "What a piece of junk!" and toss it before giving it a chance. The 91XG will soundly outperform the 9032.

Yes, yes. We hear this all the time. But mine is still holding together and I haven't heard of anyone having problems with them.

It seems that everybody looks at this thing and says, "What a piece of junk!" and toss it before giving it a chance. The 91XG will soundly outperform the 9032.


Actually, I teseted both antennas, under near identical conditions and the 9032 captured additional signal. Again, the 91XG is OVER RATED! I know you have one and like it, however, I am used to working with antennas all of time and do some design work with them, and the 91XG is rubbish.

Stick with the PR-9032!

Actually, I teseted both antennas, under near identical conditions and the 9032 captured additional signal.

I'm sure we'd all be interested in the documentation of your test. Things like when it was tested. Where. Under what type of weather conditions. Channels used and statistics of each, etc. What means was used to measure the signal. Stuff like that. No offense, but any test can be jury-rigged to give a desired result, and we have nothing but your say-so that you are an expert, or that you even did a test based on the little info you give above.

What's interesting is that according to computer modeling (http://www.hdtvprimer.com/ANTENNAS/comparing.html), the 91XG is very similar to the 9032 in net gain at channel 56 and above, but the 9032 begins to drop off below that point to a gap of almost 3dB at channel 28. The curves converge again below that point, with the advantage at channel 14 being about 1dB. Since most digital channels are not above 56 currently, and none will be above 51 come March of 2009, that type of advantage isn't saying much in favor of the 9032. The 9032 is larger, and has higher wind load. Computer modeling has its critics, but without a large amount of real-world data I tend to trust it over single-session, single-location testing.

I've always been impressed with Winegard's build quality, but remain unconvinced that the 9032 is a superior deep-fringe antenna. For anyone inside of 60 miles under typical terrain, I think either would work just fine. Beyond Grade B contours without line-of-sight, I give the nod to the 91XG.

In all fairness sregener, his name is AntennaMaster, so he knows more than everyone else by default.

...I am used to working with antennas all of time and do some design work with them, and the 91XG is rubbish.

I'm sure we'll hit my maximum bandwidth per hour limit on Geocities with everybody checking out this page, but I took some 6MP pictures using a 450mm zoom of my antenna this morning. You can inspect the images (over 1MB each, so dial-up users beware!) for any signs of wear. I couldn't see any at 400%.

http://www.geocities.com/figbert/91xgwear.html

Edit: Here's a full-rez crop, and a low-rez picture of the image without cropping. Make sure to look at the low-rez version at full (not scaled) resolution, as my browser shows the scaled image with very noticable warp of the screen due to problems with a low-rez image and slanted lines.)

I am using a 91 XG at 57 feet...I have no tests of other UHF antennas to compare it to but I can receive analog UHF at 81 miles with perfect signal quality 100% of the time...there are a couple at around 100 miles that are clear but slightly snowy. I know it outperforms anything I have ever used or seen used. I wish I had a 9032 to do my own test. As you said sregener, people are saying they are crap without any data to back up their claim...I believe it is because the 91XG is radically different from what they are used to and they refuse to accept change.

...people are saying they are crap without any data to back up their claim...I believe it is because the 91XG is radically different from what they are used to and they refuse to accept change.

Actually, the 91XG looks identical to the Funke 4591. It may even *be* a rebranded Funke 4591. I don't hear anyone complaining about the durability of those.

My first impression of the 91XG was similar to those who say it isn't durable; I wondered if it would last. So far it has, in what I think is a rather hostile environment. Maybe it really is falling apart, but it just isn't visible from ground level. Maybe I've been lucky. Maybe it will break tomorrow. Who knows?

If I read about people swapping their 9032s for 91XGs and getting worse performance, or heard of people swapping out their 91XGs for 9032s and getting better results, I'd be tempted to try it myself. But I haven't heard or read much like that (other than AntennaMaster's claim of better performance from the 9032) so I'm inclined to leave my antenna up there for now.

The DXers love the Funke 4591. They spend the dollars to get every ounce of performance they can. There aren't many stacking 9032s.

Think I've posted this a few times here. Think the XG91 and all of it's other names across the world(funke is but one, there's also one that looks the same from australia with a "jaycar" brand name, and one from another european country with a "dipol" brand name) probably all come from the company at below link --- I think The driven element may differ between different antenna models/"brands"/etc ... (note - just choose "cancel" when it says you need chinese language support - you don't, it's in english) :

http://www.ceda-antenna.com/index.htm

Details on their so called "91 element" antenna(or whatever you want to call it) - along with very detailed pictures of it are here :

http://www.ceda-antenna.com/91EL.htm

Update: Oh yes. Note that the box my XG91 from antennasdirect came in said such things as 91EL and "Made in China" on it .... I'm certianly happy with it, regardless, and don't think it is likely to fall apart any time soon ...

Actually, the 91XG looks identical to the Funke 4591. It may even *be* a rebranded Funke 4591. I don't hear anyone complaining about the durability of those.
The DXers love the Funke 4591. They spend the dollars to get every ounce of performance they can. There aren't many stacking 9032s.

The XG91 is identical except for the pickup element.The Funke was the original.A Dxer in Cape Cod has used one for several years.I'll get in touch with him and see how long he's had it in the air,and how it's holding up.The only deterioration I've seen is the gold anodizing on the director elements has faded away.Big deal.

I just got rid of a couple of 9032's.A good durable well-built antenna,but inferior bandwidth compared to the Quad-X design.As a Dxer,good performance on every channel is a must.

The Quad-X is rated for 80mph wind(1-1/2 sq.ft/35 lb lateral load).Good enough for me.

I've had this latest stack arrangement in the air since Feb 4th and it's a real "scatter-gitter".Been picking up Fox 53 from Pittsburgh(>300mi) on a daily basis under dead-band conditions.

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

So, how did you find the performace of the 91XG against the 9032's? We will not judge it on the appearance, just performance! My findings, still working on the charts, shows the 9032 to perform significantly better above Channel 35. I have the images from the scope that I will post.

I know the 9032 inside and out! It is a performer.

Srenger, you may want to just try the 9032 on your set-up. You may be surprised. Heck, I will send you a free one if you want one. Maybe, then you may understand.

So, how did you find the performace of the 91XG against the 9032's? We will not judge it on the appearance, just performance! My findings, still working on the charts, shows the 9032 to perform significantly better above Channel 35. I have the images from the scope that I will post.

I know the 9032 inside and out! It is a performer.

Srenger, you may want to just try the 9032 on your set-up. You may be surprised. Heck, I will send you a free one if you want one. Maybe, then you may understand.


I have two 9032's that I played around with for awhile. Singly, it was inferior pretty much up and down the band to both the 4228 and the DAT 75. Comparing a 9032 stack to a DAT 75 stack the DAT also won handily. It is also a little flimsy at the boom section and requires propping it up so it won't sag in the front. Winegard is widely known for exaggerating their antenna specs and I think the 9032 is a prime example. It's a decent antenna for the money though as it can be had for around 35 bucks. Here's a pic of my 9032 stack:

Srenger, you may want to just try the 9032 on your set-up. You may be surprised. Heck, I will send you a free one if you want one. Maybe, then you may understand.

Based on real-world testing done by others here, my conclusion remains the same: the 9032 is an upper-tier performer that doesn't quite reach the elite status of other models. It's not worth the $60 I'd have to pay to have the antenna put up on my tower (I don't do heights) and then $60 more to replace the inferior 9032 with my original antenna.

But the fact that you're willing to give one to me suggests that you have ulterior motives that have nothing to do with believing the 9032 is the best antenna out there. I suspect you either sell them or work for someone who does. Your tests will be interesting, but without verification that you "did everything honestly" they're going to have to be taken with a grain of salt. You also haven't given any indication of whether your tests are for near-fringe, fringe or deep-fringe. It is in the latter that I think the 91XG really shows its stuff.

Hello, I'm new here, and I was just curious to get some of your opinions on the Radio Shack VU-190 XR. I just bought it, and was checking to see some opinions. Thanks!

Hello, I'm new here, and I was just curious to get some of your opinions on the Radio Shack VU-190 XR. I just bought it, and was checking to see some opinions. Thanks!

The knock on the 190XR is durability - the Radio Shack VHF elements don't hold up well to weather (and in some cases, large birds) and will break off in a few years. The UHF section is about average - nothing special, but not the worst by far. If you need VHF, you could do far worse than the 190XR, especially if you got it at one of their half price sales. The 190XR is a tried-and-true design and will perform great as long as it takes to rust or break.

A pigeon took out an element on my VU-160XR last month. I know it was a pigeon from the gray and white fluff stuck to the end.

Wow, Greywolf, you've had an extreme makeover! :)

Sorry if this is old news, but I haven't been here in a while.

I've been playing with Avatars. The picture with the beard is 25 years old.

What phase was the moon in when it was taken?

"Warewolf!"

"Warewolf?"

"Where wolf? There! There wolf. There castle."

"Igor, why are you talking like that?"

"I thought you want to talk like that."

"I don't want to talk like that."

"Suit yourself, I'm easy"

I thought about getting the CM 3671...but already purchased the 190...by the time I found out about it. Oh well, thanks for the info!

I'm trying to sort out which kind of antenna to buy. I'll need both VHF/UHF capability and stations are at 344 degrees and 102 degrees, 13 & 3 miles away respectively. I was hoping that a stationary antenna like the two on ebay might work. One is a Terk HDTV-S outdoor and the other is a Wineguard SS-1000. You can see them if you type in ebay's search "HDTV Antenna".

Both station sites are on unobstructed mountain tops.

TV is still in the box and I will start out with some rabbit ears and work up. Please don't make it too technical for me!

Thanks,

Tom

girzzfan,
My guess is that the rabbit ears will work well enough that you won't want to change.

I'll give the ole rabbit ears a try! Thanks

Tom

TV is still in the box and I will start out with some rabbit ears and work up. Please don't make it too technical for me!

Unamplified is the key. Don't get anything that you have to plug into a power outlet.

I'd suspect that for VHF at least, that's going to work. For UHF, if you need to, you may want to try a double-bowtie design like the one at Radio Shack, or the AntennasDirect DB2. Even the single bowtie that Radio Shack sells for about $5 would probably work for you.

Take a ChannelMaster 4221 4-bay antenna. Or, a 4228 8-bay antenna. Now, go to Lowe's, get $4 worth of aluminum window screening.
Cut to two 4' strips, and then make holes every 6 inches or so.
Tie wrap the mesh screen behind the 4221 or 4228. Instant front-to-back rejection of several dB added on, and better receive gain as well. NOTE: do NOT try this on a 4228 mounted outside. The wind load would be killer, and the screen may just rip off anyway.

No effect at all whatsoever for my location - zip 27587 - NBC 17 is kind of marginal although I have everything else coming in pretty well.

Anyone actually see an improvement doing this?

Thanks,
-Jim

I'll give the ole rabbit ears a try! Thanks

Thanks Neil & srengener. This will be a big weekend trial & error for me and I'm pretty fussy about PQ even on my SD stuff.

Now, just in case I might have to go to an outdoor VHF/UHF antenna on the roof, I've been contemplating cable management, grounding and such.

Can I string the coax and bare copper ground wire down the gutter down spouts? (they are aluminum or very light steel). That would be fortunate if I could as the entry point for the coax into the house is very close to one down spout. And it solves the problem of looping the coax etc over the gutters which would look messy.

Any thoughts on this would be appreciated.

Tom

1) This will be a big weekend trial & error for me and I'm pretty fussy about PQ even on my SD stuff.

2) Can I string the coax and bare copper ground wire down the gutter down spouts? (they are aluminum or very light steel).


1) As you no doubt know, with digital, either the picture quality is perfect or its very bad. Once you have a glitch-free image, you're done. Maxing out the signal quality meter beyond that point gains you nothing.

2) Coax, yes. Bare copper? I doubt it, as the contact with the conductive material of the down spout would interfere. But greywolf is the expert on grounding, so maybe he'll chime in.

The only thing that comes to mind is a conduit situation. When a bare grounding wire is run through metallic conduit, it is supposed to be connected to the conduit at both the entry and exit points. The best idea is to check with your local building department. Codes can vary from region to region. I actually like the idea of grounding the gutter system though. I hadn't really thought about it before but an ungrounded gutter system can be somewhat of a lightning attractor at least in theory.

AntAltMike is the expert. I just post what I've learned and wait to see if he corrects me.

Seems Greywolf has finally discovered that ever elusive Fountain of Youth. Does this mean we will soon be seeing him in his own infomercial?

Thanks Neil & srengener. This will be a big weekend trial & error for me and I'm pretty fussy about PQ even on my SD stuff.

Now, just in case I might have to go to an outdoor VHF/UHF antenna on the roof, I've been contemplating cable management, grounding and such.

Can I string the coax and bare copper ground wire down the gutter down spouts? (they are aluminum or very light steel). That would be fortunate if I could as the entry point for the coax into the house is very close to one down spout. And it solves the problem of looping the coax etc over the gutters which would look messy.

Any thoughts on this would be appreciated.

TomI think running bare copper down an aluminium or steel down spout
is likely to result in a severe corrosion problem. You have got two dissimilar metals
in a wet environment = battery= electrolysis. I don't think I would want to take a
chance on doing that.

wb

Neil Lafoon posted:

girzzfan,
My guess is that the rabbit ears will work well enough that you won't want to change.

Thanks for all the help and assistance here about antennas, rabbit ears, grounding and the like. You can't know how much I appreciate your comments.

But here is ground truth: Neil is right!! Rabbit ears in my location is absolutely stunning and perfect. Amazing how 1950s antenna technology works!! Watched the George Mason - Florida game and we were jaw-agape stunned by the picture. Noticed a little picture wiggle on NBC and ABC, but couldn't be happier with the PQ on CBS. Maybe a little adjustment of the rabbit ears is in order.

Tom

What would be your preference a CM 4228 or a CM 4221 with a Radio Shack in line amplier (10 dB)?

I purchased a CM4221, which allows me to pick up everything locally and two stations (50 miles away). Sometimes (but not theat often) I can pick up a station (70 miles away) and a station (90 miles away). Decided to add an inline amplier yesterday (picking up both these stations better, but still have drop out every 10 minutes or so.

I can purchase a CM 4228 for $50, but will not be able to return it. Before spending the money, I wanted to get some advice from others. What is my best option?

My preference is the CM4228 -- without the amp.

You can always add an amp if needed, and in most cases it is not.

An amp is useful only if you have a long cable run.

It will not pick up stations that aren't there.

An amp amplifies everything -- signal and noise, and an amp can even kill a signal when you think you should be getting it.

Decided to add an inline amplier yesterday (picking up both these stations better, but still have drop out every 10 minutes or so.

I can purchase a CM 4228 for $50, but will not be able to return it. Before spending the money, I wanted to get some advice from others. What is my best option?

My personal advice is to get a preamp before upgrading your antenna in this situation. However, nothing may solve your occasional dropouts for stations beyond the radio horizon. In fact, if you're only getting dropouts every 10 minutes or so, you're doing very, very well.

Good preamps are made by Winegard and Channel Master. They come in two parts. One goes near the antenna, and the other goes near the receiver. The benefit is that you amplify the signal before all of the line loss. You don't need to run any additional cable because the indoor unit sends the power up the coaxial line that you already use. (Note: This will cause problems if you're using a diplexer.)

If your local stations are 15+ miles away, just about any preamp from Winegard should be okay, and if you're 25+ miles away, any of the Channel Masters should be okay. If your stations are closer, you may want to use the Winegard HDP-269 which is especially designed *not* to overload when there are strong signals nearby.

Generally speaking, inline amplifiers are really bad, and the fact that things are any better for you is somewhat surprising.

What would be your preference a CM 4228 or a CM 4221 with a Radio Shack in line amplier (10 dB)?

The Radio Shack inline 10dB amp is nearly useless for your application. It has a noise figure of I think 4 or 5dB, and a maximum output of not much more than 30dBmV, meaning it will get overloaded by the stronger local broadcasts.

I sometimes use that product to boost the "return" signal strength in hotel pay-per-view movie systems, but there just aren't very many other useful applications for it as an antenna preamplifier.

Update: I have just seen a current production unit of this product and it now says it works from 50Mz to 2,000Mz, whereas it used to say 5-1000Mz, so I won't be using any new ones to amplify return signals, but otherwise, it looks like the same piece of junk as the earlier version.

What would be your preference a CM 4228 or a CM 4221 with a Radio Shack in line amplier (10 dB)?

I purchased a CM4221, which allows me to pick up everything locally and two stations (50 miles away). Sometimes (but not theat often) I can pick up a station (70 miles away) and a station (90 miles away). Decided to add an inline amplier yesterday (picking up both these stations better, but still have drop out every 10 minutes or so.

I can purchase a CM 4228 for $50, but will not be able to return it. Before spending the money, I wanted to get some advice from others. What is my best option?

Given the choice between adding amplification and getting a bigger, better antenna I can't imagine a situation in which I'd choose amplification.

Given the choice between adding amplification and getting a bigger, better antenna I can't imagine a situation in which I'd choose amplification.

Well, if directionality is an issue (i.e. he needs a wide acceptance angle) a bigger antenna will be more directional and might require the addition of a rotor, while the smaller one with a preamp will still have the wide acceptance angle. The other thing is that preamps can be returned - antennas usually can't.

Well, if directionality is an issue (i.e. he needs a wide acceptance angle) a bigger antenna will be more directional and might require the addition of a rotor, while the smaller one with a preamp will still have the wide acceptance angle. The other thing is that preamps can be returned - antennas usually can't.

Good point, I should know better to talk in such absolutes. :)

Maybe I've been away too long.

You guys know waaay more than I do. So consider me a complete antenna newb and help me out...

My Sony 42a10 will be here on April 11th, so I won't know how well it picks up OTA HD until then. We have basic cable so I'm only concerned with getting whatever digital/HD stations I can over the air. Plugging into antennaweb.org, my address is close to 140 derby downs, newark, OH, 43055. (please don't stalk me, I'm not worth it.) Other nearby addresses show the digital versions of CBS/ABC etc coming in fine. As for what I get, the distances range from 10 miles to the local religious channel (which has Cavs games sometimes) to 26 miles for one NBC affiliate and PBS, to 34 miles for the main ABC/CBS/NBCout of Columbus. ABC/CBS/NBS all seem to be coming in from the same direction (260 deg). That's my reception situation according to that website (although it claims that it is conservative).

My friend has recommended that I stick with a $35 antenna and to put it in my attic. However he didn't tell me what kind, make/model, or anything. The closest I'm getting to the attic is the crawlspace behind my closet, and this heads away from the direction I'd like to point. My window points in the exact direction I'd like to receive from (260 deg).

Can anyone recommend (with a link) a make/model indoor antenna for around $35 or less? Preferably less. I'd like to start with a cheapie and see what I get, but like I said in the beginning, I don't know half of what I'm talking about when it comes to this stuff, I'm fairly proficient in most other tech stuff though.
This? (http://www.newegg.com/Product/Product.asp?Item=N82E16882145022)
Or maybe this?? (http://www.radioshack.com/product/index.jsp?productId=2062079&cp=&pg=8&y=5&s=A-StorePrice-RSK&x=13&kw=antenna&parentPage=search)
Or lastly maybe this cheapest? (http://www.radioshack.com/product/index.jsp?productId=2062017&cp=&pg=2&y=5&s=A-StorePrice-RSK&x=13&kw=antenna&parentPage=search)

any idea why all of a sudden turning on an fm trap on a leviton amp would make a more stable signal? I've been running a few months with it off (125ft run) but just flipped it last night for the fun of it and it's more stable now

i was troubleshooting an HDtivo problem with one tuner out completely and was disconnecting everything in my system to see if there was corrosion and everything was perfect...but decided to hit the trap and voila, wife yelled that there was a more stable signal. weird...was it the leaves on the tree? (200 ft away) :)

I'd try a Channel Master 4221 [or 3021, same model]. It's a good all-round UHF antenna, about $30 including shipping.

I would avoid Terk. The RS models might work well in strong signals areas.

This silly-looking RS model 15-624 [$15] has gotten good reports from other users:

http://www.radioshack.com/product/index.jsp?productId=2103058&cp=&pg=6&y=7&x=12&kw=antenna&s=A-StorePrice-RSK&numProdsPerPage=20&parentPage=search

I believe this model was discontinued, glad to see it's back.

any idea why all of a sudden turning on an fm trap on a leviton amp would make a more stable signal? I've been running a few months with it off (125ft run) but just flipped it last night for the fun of it and it's more stable now.



FM stuff sits between VHF channels 6 and 7, so if any of your HDTV channels are near those, it guess it could make a difference.
Most HD channels are in the UHF range, though.

any idea why all of a sudden turning on an fm trap on a leviton amp would make a more stable signal? I've been running a few months with it off (125ft run) but just flipped it last night for the fun of it and it's more stable now

i was troubleshooting an HDtivo problem with one tuner out completely and was disconnecting everything in my system to see if there was corrosion and everything was perfect...but decided to hit the trap and voila, wife yelled that there was a more stable signal. weird...was it the leaves on the tree? (200 ft away) :)
A strong FM station(s) was overloading your amp or receiver front-end.

Ron

i should have noted my uhf is 26 32 42 54 64 67..sorry...plus i'm sitting here waiting for the neighbors tree to fill in...the antenna installer did warn me about it but there was literally only one place on the roof to get in all these channels reliably ....in winter at least :)

please cross you fingers and pray for me...if leaves hinder me, i'll .......chainsaw?

The full, healthy oak trees surrounding our property have never been an issue, even on windy summer days, FWIW.

[15 miles from NYC, CM4221/3021 on the roof, installed in 4/2000]

I'd try a Channel Master 4221 [or 3021, same model]. It's a good all-round UHF antenna, about $30 including shipping.

I would avoid Terk. The RS models might work well in strong signals areas.

This silly-looking RS model 15-624 [$15] has gotten good reports from other users:

http://www.radioshack.com/product/index.jsp?productId=2103058&cp=&pg=6&y=7&x=12&kw=antenna&s=A-StorePrice-RSK&numProdsPerPage=20&parentPage=search

I believe this model was discontinued, glad to see it's back.

I'll check them out, and report back once it's time. Thank you!

The full, healthy oak trees surrounding our property have never been an issue, even on windy summer days, FWIW.

[15 miles from NYC, CM4221/3021 on the roof, installed in 4/2000]

is your antenna pointed right at /thru the treest

interesting observation. So then by his trees being well over 200 ft away then that means even in full bloom i wont have problem right? :)

is your antenna pointed right at /thru the treest

interesting observation. So then by his trees being well over 200 ft away then that means even in full bloom i wont have problem right? :)

Yes, it's aimed directly at the trees [there's no choice, really...] and they're about 75' away.

I've been recording many, many programs over the years on the HD DirecTivo and the PC card recorders and they've been remarkably glitch-free. RF stuff can be weird and sometimes unpredictable, so YMMV.

I'm within 5 miles of most transmitters, and have decent reception using a Silver Sensor indoors during the winter. When the trees (many within 50 feet) leaf out, you can pretty much forget HD, especially when it's windy. Moving the antenna to the attic, and even outside (but not on the roof) doesn't help! I'm very reluctant to try going in the attic, or even on the roof with a 4221, given my experience with the Silver Sensor.

solfan well you are luckier than me....i'm watching something from a weaker channel i recorded last night and the dropouts are killing me.....it could be the hdtivo...just no way to tell

"HD and digital broadcasts are not in the UHF or VHF band, they are ATSC, and your television being an A10 has the built in ATSC tuner."

A friend told me this. Is he correct? (about the UHF/VHF/ATSC. I know my a10 has an ATSC tuner) I thought the digital signal was passed along the UHF, and in rare cases along the VHF bad. Can someone clear this up so I can show him how much smarter I am? :D

Hi, I live in The Bronx, NY 10462 and was wondering if anybody was having trouble picking up the following stations:

WNYE-DT 25.1
WNJU-DT 36
WFUT-DT 68.1
WLIW-DT 21.2 (This is out of Long Island)

I'm able to pickup all other stations in my area except those mention above. See the list below.

2-1 WCBS-HD
4-1 WNBC-HD
4-2 WX-PLUS
4-4 WNBC 4.4
5-1 WNYW-DT
5-2 WWOR DT
7-1 WABC-HD
7-2 WABC+
7-3 WABC NOW
9-1 WWOR DT
9-2 WNYW DT
11-1 WB11 ENGLISH
11-2 WB11 SPANISH
13-1 WNET-HD
13-2 WNET-SD
13-3 WNET-13
31-1 i
31-2 PAX
31-3 WORSHIP
31-4 FAITHTV
41-1 WXTV-DT
68-1 WFUT DT (Programming schedule only - NO AUDIO OR VIDEO)

On a followup question, I wanted to combine Two UHF and One VHF antennas. I was told that the two UHF antennas might cxl eachother out. Any suggestions.

P.S. I will be installing a new 42XG antenna on my roof.

"HD and digital broadcasts are not in the UHF or VHF band, they are ATSC, and your television being an A10 has the built in ATSC tuner."

A friend told me this. Is he correct? (about the UHF/VHF/ATSC. I know my a10 has an ATSC tuner) I thought the digital signal was passed along the UHF, and in rare cases along the VHF bad. Can someone clear this up so I can show him how much smarter I am? :DYou are correct. Your friend is incorrect.

wow even i knew that one....we only have 2 choices..uhf and vhf...if he was old enough he'd remember tvs with the dial on the bottom that had the notations

My preference is the CM4228 -- without the amp.

You can always add an amp if needed, and in most cases it is not.

An amp is useful only if you have a long cable run.

It will not pick up stations that aren't there.

An amp amplifies everything -- signal and noise, and an amp can even kill a signal when you think you should be getting it.

Is this true or a matter of debate? So, if you have a short cable run, a pre-amp will not give you a better ability to get more distant stations? I had been told that a pre-amp can increase your ability to get distant stations.

I have tried a wingard preamp (17 db VHF/28 db UHF) when using a 20' run of RG6...there was a dramatic improvement...stations that were very weak became clear.

In over 35 years of experimenting with TV reception, I don't remember a time when a preamp didn't help a weak signal. Now if you are near some very strong signals, a preamp can cause problems by overloading the receiver.

About two years ago a radio/antenna design engineer wrote a very positive review of the Motorola TV Signal Booster. I found one on Ebay and gave it a try. It really does work very well, even on small indoor antennas. I now know several who are using this unit with very little overload, even in strong signal areas. It even works almost as well as a Winegard or CM preamp with the 91XG antenna on weak signals (analog and digital). I use another Motorola Signal Booster with a high-band VHF antenna to pull in a DTV on ch. 11 @ 40 miles which is sometimes too weak to lock in without the booster.

Steve

Correct -- if you have stronger locals, they may swamp out your weaker signals when you use a pre-amp -- they get amplified too.

The amp can't distinguish which signals you need and amplifies everything -- weak, strong, noise, multi-path, etc., and the net result is stations you expect all of sudden don't come in.

If all you have are weak signals in your area, amp may help.

Has anyone tried these preamps?
http://www.gme.net.au/matv/mhw_series.php
34 db UHF gain with NF of <2.5

Gents,

Can you give me some feedback on your opinion with RG6Quad Cable? The antenna installer, usually only has the average RG6 on his truck.

With adding some new antennas, I was wondering if I should replace the existing cable. It is about 6 years old.

Here are some questions:

1) Using F660BVV, would it warrant to pay the extra money to get the DigiCon Cable with the connectors already attached?

http://www.solidsignal.com/prod_display.asp?CAT=Wire%20Cables&PROD=DGCBL100

The purpose of getting this, is the advantage of having the connnectors alreayd applied. I realize that this is adding additional cost, however, most of the local antenna installers have issues with putting on "quality" connectors.

2) Or should I just stick with the standard F660BV?

Thanks for your support!

Can you give me some feedback on your opinion with RG6Quad Cable? The antenna installer, usually only has the average RG6 on his truck.
Feedback on this subject will not teach you anything useful. Quad shield does what it is purported to and doesn't do what it isn't purported to. Any feedback that tells you otherwise will only be useful for confirming one's prejudices.

It has nearly the same dB loss per unit length as dual shield. Its "improved" shielding is irrelevant in about 99.999% of all reception situations. It MIGHT make a difference to someone whose house is in the shadow of a full-powered transmitting tower, but I have a few customers in such situations and they have no trouble with dual shield.

Quad shield is favored by the cable companies because they are responsible for controlling the "cumulative leakage" of their signals on certain frequencies that are shared by other services, They are concerned that the total signal egress of their entire system will exceed a certain level as measured in "flyover" surveys and are willing to pay an extra penny per foot to incrementally reduce it a tiny bit. Since broadcast TV signals aren't at those frequencies, then their low level egress leakage is not a problem that the FCC cares about.

The other reason cable companies favor quad shield, in addition to the slight theoretical improvement in shielding factor, is that with four layers of shielding, the cable shielding is less likely to fail due to exterior physical trauma.


... most of the local antenna installers have issues with putting on "quality" connectors.

I haven't seen any professional installer (other than me) use crimp connectors in the last couple of years, and I have no basis for believing that any compression connector is any better than any other, except that some do not have an internal "O" ring on the base mating surface of their 3/8" nut and therefore are not suitable for outdoor use unless they are somehow weatherized, like with coax seal, "Stuff", or weather boots)

Feedback on this subject will not teach you anything useful. Quad shield does what it is purported to and doesn't do what it isn't purported to. Any feedback that tells you otherwise will only be useful for confirming one's prejudices.

It has nearly the same dB loss per unit length as dual shield. Its "improved" shielding is irrelevant in about 99.999% of all reception situations. It MIGHT make a difference to someone whose house is in the shadow of a full-powered transmitting tower, but I have a few customers in such situations and they have no trouble with dual shield.

Quad shield is favored by the cable companies because they are responsible for controlling the "cumulative leakage" of their signals on certain frequencies that are shared by other services, They are concerned that the total signal egress of their entire system will exceed a certain level as measured in "flyover" surveys and are willing to pay an extra penny per foot to incrementally reduce it a tiny bit. Since broadcast TV signals aren't at those frequencies, then their low level egress leakage is not a problem that the FCC cares about.

The other reason cable companies favor quad shield, in addition to the slight theoretical improvement in shielding factor, is that with four layers of shielding, the cable shielding is less likely to fail due to exterior physical trauma.




I haven't seen any professional installer (other than me) use crimp connectors in the last couple of years, and I have no basis for believing that any compression connector is any better than any other, except that some do not have an internal "O" ring on the base mating surface of their 3/8" nut and therefore are not suitable for outdoor use unless they are somehow weatherized, like with coax seal, "Stuff", or weather boots)


I agree on the use of quad shield,not necessary,and crimp connectors are a real PITA to install on most brands of coax.Have to nip off all the shielding and push like hell with a 7/16 socket to get the fittings down far enough.

Your last paragraph brings up a good point.I've seen these so-called weatherproof compression fittings on pre-made cables under the Zenith brand name.No O-ring,and I can't believe water won't find its way around those threads.

You guys know waaay more than I do. So consider me a complete antenna newb and help me out...

My Sony 42a10 will be here on April 11th, so I won't know how well it picks up OTA HD until then. We have basic cable so I'm only concerned with getting whatever digital/HD stations I can over the air. Plugging into antennaweb.org, my address is close to 140 derby downs, newark, OH, 43055. (please don't stalk me, I'm not worth it.) Other nearby addresses show the digital versions of CBS/ABC etc coming in fine. As for what I get, the distances range from 10 miles to the local religious channel (which has Cavs games sometimes) to 26 miles for one NBC affiliate and PBS, to 34 miles for the main ABC/CBS/NBCout of Columbus. ABC/CBS/NBS all seem to be coming in from the same direction (260 deg). That's my reception situation according to that website (although it claims that it is conservative).

My friend has recommended that I stick with a $35 antenna and to put it in my attic. However he didn't tell me what kind, make/model, or anything. The closest I'm getting to the attic is the crawlspace behind my closet, and this heads away from the direction I'd like to point. My window points in the exact direction I'd like to receive from (260 deg).

Can anyone recommend (with a link) a make/model indoor antenna for around $35 or less? Preferably less. I'd like to start with a cheapie and see what I get, but like I said in the beginning, I don't know half of what I'm talking about when it comes to this stuff, I'm fairly proficient in most other tech stuff though.
This? (http://www.newegg.com/Product/Product.asp?Item=N82E16882145022)
Or maybe this?? (http://www.radioshack.com/product/index.jsp?productId=2062079&cp=&pg=8&y=5&s=A-StorePrice-RSK&x=13&kw=antenna&parentPage=search)
Or lastly maybe this cheapest? (http://www.radioshack.com/product/index.jsp?productId=2062017&cp=&pg=2&y=5&s=A-StorePrice-RSK&x=13&kw=antenna&parentPage=search)
None of those antennas are going to reliably receive Columbus, and you will probably find the CM-4221/3021 to be inadequate indoors at 34 miles away.

Antennaweb only shows you being able to reliably receive two nearly DTV stations: i-PAX (10 mi, 181 deg) and PBS (26 mi, 286 deg)....that's with an outdoor antenna on a pole.

It appears that you need an antenna with a significant amount of gain in order to work towards receiving the Columbus DTV group 34 miles away (260 degrees).
The other NBC affiliate you mention (26 mi, 122 deg) would be in the sidelobe of any antenna pointed towards Columbus, and would be very difficult to receive.
With the W31AA PBS station (1 mi, 113 deg) being nearly in your backyard, avoid using any amplified antennas, preampliers or distribution amplifiers.
They WILL be overloaded--indeed your HDTV may also be overloaded although loss in the downlead and RF Splitters will reduce the amount of overload.

For your attic mounted situation, and since a preamp can not be used, I would recommend the higher gain CM-4228 8-Bay antenna.
It also has a deep sidelobe null that can significantly reduce the signal level coming from W31AA PBS.

Uniquely, the CM-4228 also provides significant gain in the VHF band, which is needed to receive the digital ABC station on CH13.
And a couple years from now will be needed when other stations move their digital stations to the original analog allocations.

If you find that reception reliability still isn't as good as you'ld like, consider moving the antenna to an outdoor location, either against the eves or on a pole.

Antennaweb only shows you being able to reliably receive two nearly DTV stations: i-PAX (10 mi, 181 deg) and PBS (26 mi, 286 deg)....that's with an outdoor antenna on a pole.

Antennaweb's digital predictions are a little conservative. Okay, maybe a lot. For my address, they predict I'll only get one, and I got three just fine (i.e. perfect) from my rooftop before I moved things up a tower to get much more distant stations.

Generally speaking, if Antennaweb predicts you'll get analog UHF signals from an area, you'll get the digitals whether Antennaweb lists them or not.

That said, most of his digitals are listed as blue or violet, so he'll need a minimum of an outdoor antenna, installed outdoors, like the CM3021. The 4228 would be better.

I am looking for a good Attic antenna to pick up only Digital HDTV channells out of Philadelphia. I live at 19977 and I have The Dish 811 Reciever with Hitachi 50/v500 Rptv. The run of cable would be around 50 ft. of rg6. Is there any tpe of antennas anyone can recammend? I mainly watch the locals but Dish doesn't have them in HD yet and the HD package isn't worth it without them. Thanks

Did you even attempt antennaweb.org mentioned in previous post?

Anyway, in an attic, 60 miles away, you got problems. Throw a Channelmaster 4228 on the roof, and if you add a rotor, maybe get Baltimore as well.

I am looking for a good Attic antenna to pick up only Digital HDTV channells out of Philadelphia. I live at 19904 and I have The Dish 811 Reciever with Hitachi 50/v500 Rptv. The run of cable would be around 50 ft. of rg6. Is there any tpe of antennas anyone can recammend? I mainly watch the locals but Dish doesn't have them in HD yet and the HD package isn't worth it without them. Thanks

Yes, I tried antennaweb. I can't have a antenna on the roof here its against our association and it would look unsightly.

Your home owners association cannot stop you http://www.keohi.com/keohihdtv/hdreception/fccrules.html but perhaps unsightly can.

Yes, I know that,but out of 450 homes I would be the only one with a huge antenna sticking up.Would be like moths to a flame in my community. I am still searching for something I can put up in my attic it isn't used for anything else.Plenty of room.Thanks

Yes, I know that,but out of 450 homes I would be the only one with a huge antenna sticking up.Would be like moths to a flame in my community. I am still searching for something I can put up in my attic it isn't used for anything else.Plenty of room.Thanks

Who cares? It's your home. Do what you like and let the community pests fume their lives away.

red - uhf WEVD-LP 27 ABC DOVER DE 81° 4.2 27
blue - uhf W14CM 14 TBN DOVER DE 81° 4.2 14

These two present the problem - you won't be able to use most preamplifiers, and for weak distant signals, a preamp is a big help.

I'd try a Channel Master 4228 (8-bay bowtie.) You might try a Winegard HDP-269 preamp, which is designed not to overload, but it may not help and might make things worse. You wouldn't know for sure until you tried.

However, with the install in your attic, count on reception problems when you can least afford them.

The 4228 isn't that large - it's 4'x4'. It's also a top performer. As others have said, your HOA can take their illegal rule and forget it. The case studies at the bottom of this page (http://www.fcc.gov/mb/facts/otard.html) should help if you're not feeling brave.

The 811 is a terrible receiver for your situation, though. You need a strong OTA box like the LG, Zenith, or some of the newer models from other major manufacturers. The 811 will fail with good signals, and it's highly unlikely that yours will even be adequate.

In over 35 years of experimenting with TV reception, I don't remember a time when a preamp didn't help a weak signal. Now if you are near some very strong signals, a preamp can cause problems by overloading the receiver.

About two years ago a radio/antenna design engineer wrote a very positive review of the Motorola TV Signal Booster. I found one on Ebay and gave it a try. It really does work very well, even on small indoor antennas. I now know several who are using this unit with very little overload, even in strong signal areas. It even works almost as well as a Winegard or CM preamp with the 91XG antenna on weak signals (analog and digital). I use another Motorola Signal Booster with a high-band VHF antenna to pull in a DTV on ch. 11 @ 40 miles which is sometimes too weak to lock in without the booster.

I'm hoping someone with more antenna/RF signal knowledge can shed some light. I've got a situation where a Channel Master 7777 preamp (supposedly a very good preamp) completely kills my reception. Should I be seeing this?

I've got a roof mounted Channel Master 4221 4 bay bow-tie antenna. I receive a number of stations just fine, but a few are too weak to get DTV reception. The antenna is connected to my tuner with about 30 feet of RG-6: as part of this connection there is a mask-mounted 7777 preamp in the line. If I don't supply any power to the 7777, I get decent reception on most channels. If I plug in the power-module for the 7777 my signal reception will drop to 0% on all channels. The power module is connected correctly (tv side to the tv about 4 feet of RG-6 away, power side to the preamp up on the mask, about 30 feet of RG-6 away).

Thinking that I might be amping the signal too much, I put an attenuator in the line (between the TV and the 7777 power module). This did not change anything (but the attenuator appeared to be working as expected when the 7777 power module was not plugged in).

So is there something wrong? Should the CM 7777 help my signal or totally destroy it?

I receive a number of stations just fine, but a few are too weak to get DTV reception. The antenna is connected to my tuner with about 30 feet of RG-6: as part of this connection there is a mask-mounted 7777 preamp in the line. If I don't supply any power to the 7777, I get decent reception on most channels.

So is there something wrong? Should the CM 7777 help my signal or totally destroy it?

Based on what you describe, the CM7777 should totally destroy it.

How do you know the problem is a weak signal, and not a nosiy/multipath-ridden one?

When you don't supply power to the 7777, it doesn't pass signals through - it blocks them completely. So you're getting reception from your RG-6 and any exposed metal in the line (connectors and the like.) That seems to me to indicate that you've got very strong signals. And in the presence of very strong signals, the 7777 is going to overload, destroying your reception.

Everybody please can we drop the Civic association BS. I am looking for an attic antenna that will pick up the basic Digital HDchannels in my area ABC,CBS,NBC ...........

violet - vhf WPVI 6 ABC PHILADELPHIA PA 27° 63.2 6
violet - vhf WCAU 10 NBC PHILADELPHIA PA 27° 63.2 10
violet - vhf KYW 3 CBS PHILADELPHIA PA 27° 63.2 3

Those channels listed are analog, not digital, and won't give you HD. Antennaweb undoubtably is not predicting that you'll get digital reception from those stations at your distance. In other words, getting the digital stations to come in *at all* is going to be difficult or impossible, even if you did everything right.

I have a 54' tower and an AntennasDirect 91XG, one of the best performing UHF antennas on the market, combined with a 28dB preamp (which you couldn't use because of strong local signals) and I *still* don't get reliable reception from digital stations 60 miles away.

Attic loss is anywhere from 8-12dB or so, which means you're going to take the already weak signals from Philadelphia and weaken them further by placing your antenna inside.

Quite simply, the reason nobody is giving you a "do this, I'm sure it will work" answer is that what you're trying to do is so unlikely to work that most aren't even bothering to reply to you. I already gave you my advice for what you can try, but you need to be realistic that it may not work at all, or may only work some of the time. You might have no trouble with one channel, but the others refuse to cooperate. Nobody else can realistically promise you better results, though their solutions may vary slightly.

The laws of physics won't change just because you want them to. And that's no civics BS.

Everybody please can we drop the Civic association BS. I am looking for an attic antenna that will pick up the basic Digital HDchannels in my area ABC,CBS,NBC ...........

violet - vhf WPVI 6 ABC PHILADELPHIA PA 27° 63.2 6
violet - vhf WCAU 10 NBC PHILADELPHIA PA 27° 63.2 10
violet - vhf KYW 3 CBS PHILADELPHIA PA 27° 63.2 3

If you don't want an outdoor antenna at that distance then you'd better call your cable co. or satellite provider to provide your locals.

So is there something wrong? Should the CM 7777 help my signal or totally destroy it?

I agree with Sregener. You don't say how close you are to your stations but it sounds like you are too close for a preamp. You're probably getting overload. Take it out of the loop entirely and see what happens.

Thanks for the honesty guys.I realized after reading your posts that the stations I mentioned where not Digital and also that the zip code where I live is missleading from antennaweb. I looked across the highway from my house where there is a store and went online to check the Zip it is different.The reason being is that when this community was started there was no local post office so we got grouped in with Dover but I live closer to Smyrna.I put in the new Zip and this is what I came up with. Also new wrinkle is that wife doesn't want antenna on roof. End of story its not worth the fights over this.I have been looking at 2 models of antennas that I can fit up in the attic. Does the 14-69 mean that I won't be able to use it on 3.1,6.1 channels?

40" Boom Length, 17 Elements Outdoor Antenna for UHF-Only (Channels 14-69) Catalog #: 15-2160 (RadioShack)

Channel Master 4228 (8-bay bowtie.)

* violet - uhf
KYW-DT 3.1 CBS PHILADELPHIA PA 31° 54.9 26
* violet - uhf
WYBE-DT 34.1 PBS PHILADELPHIA PA 31° 54.9 34
* violet - uhf
WPSG-DT 57.1 UPN PHILADELPHIA PA 31° 54.9 32
* violet - uhf
WPVI-DT 6.1 ABC PHILADELPHIA PA 31° 54.9 64

Based on what you describe, the CM7777 should totally destroy it.

How do you know the problem is a weak signal, and not a nosiy/multipath-ridden one?

When you don't supply power to the 7777, it doesn't pass signals through - it blocks them completely. So you're getting reception from your RG-6 and any exposed metal in the line (connectors and the like.) That seems to me to indicate that you've got very strong signals. And in the presence of very strong signals, the 7777 is going to overload, destroying your reception.
Hmmm....I hope you are correct. However, that doesn't seem to match what I'm seeing: in particular, the recieved signal strength is sensitive to the orientation of the CM antenna, which I don't think it would be if I was only getting reception from the RG-6 and exposed metal in the line. I will however, remove the 7777 preamp from the mask and see what happens.

The problem seems to be a weak signal because I have issues only with the most distant stations, which register a weak dB signal on my signal checker application.

I agree with Sregener. You don't say how close you are to your stations but it sounds like you are too close for a preamp. You're probably getting overload. Take it out of the loop entirely and see what happens.
The stations that I'm getting fine are mostly between 4 and 6 miles away, but I'm also getting one that's 22 miles away just fine. I'm trying to get a PBS station that is listed as 29 miles away. It comes in, but the signal level is only about 9 dB and it's not enough for my DTV tuner (a Divco Fusion 5) to grab a consistent picture.

I would have thought that the attenuator (which is adjustable) would have toned down any excessive amplification. And even if the CM 7777 preamp was overloading the local stations, I wouldn't expect it to completely kill the signal on the weak station that I'm trying to get. But then, I'm not that RF knowledgeable.

Sregener thinks that with the CM 7777 un-powered but still in the line, I'm not getting any signal from the antenna....I'm going to take the un-powered CM 7777 out of the loop and see what happens.

Thanks for the suggestions.

I have been looking at 2 models of antennas that I can fit up in the attic. Does the 14-69 mean that I won't be able to use it on 3.1,6.1 channels?

40" Boom Length, 17 Elements Outdoor Antenna for UHF-Only (Channels 14-69) Catalog #: 15-2160 (RadioShack)

Channel Master 4228 (8-bay bowtie.)

* violet - uhf
KYW-DT 3.1 CBS PHILADELPHIA PA 31° 54.9 26
* violet - uhf
WYBE-DT 34.1 PBS PHILADELPHIA PA 31° 54.9 34
* violet - uhf
WPSG-DT 57.1 UPN PHILADELPHIA PA 31° 54.9 32
* violet - uhf
WPVI-DT 6.1 ABC PHILADELPHIA PA 31° 54.9 64

You're still pushing things at 55 miles. It can be done if your terrain is really flat between you and the transmitters, or your location is significantly higher than average terrain, but I'd guess you're still going to have difficulty with an indoor/attic install. Realistically, I don't recommend attic installs for *anyone*, but they do seem to work okay for most inside of 30 miles. For above-average installs with a lot of luck, I've seen 70 miles done. You're still rolling the dice, though.

The Radio Shack is vastly inferior to the 4228.

You will have problems with WPVI-DT after the analog shutoff with these antennas, because WPVI will revert to channel 6. The others will all stay on channels 14-51. (The 3.1, 6.1 etc. are *virtual* channel numbers, and are not the channels they actually broadcast on. Those are the last number in each line. For instance, WPVI is using channel 64 currently to broadcast digitally.) When that happens, you can add a "cut-to-channel" antenna for channel 6 and combine it with your UHF downlead. It is probable that you wouldn't have trouble with WPVI-DT then, except during thunderstorms.

1) The stations that I'm getting fine are mostly between 4 and 6 miles away, but I'm also getting one that's 22 miles away just fine. I'm trying to get a PBS station that is listed as 29 miles away. It comes in, but the signal level is only about 9 dB and it's not enough for my DTV tuner (a Divco Fusion 5) to grab a consistent picture.

2) I would have thought that the attenuator (which is adjustable) would have toned down any excessive amplification. And even if the CM 7777 preamp was overloading the local stations, I wouldn't expect it to completely kill the signal on the weak station that I'm trying to get. But then, I'm not that RF knowledgeable.


1) With stations that close, you can't use the 7777. It *will* overload. You shouldn't need amplification for a station 29 miles away, either, unless they're at very low power or are broadcasting from the ground.

2) The problem is that an amplifier isn't a smart device - it doesn't know what signals are strong and what ones are weak. It takes the whole spectrum as input and boosts the waveform. The strongest signals are probably somewhere between 100 and 1000 times stronger than the weakest ones. The amplifier spends most of its voltage boosting those, as they make up most of the input voltage. And once they overload, the signal gets garbled. Attenuating it after that point doesn't matter - the signal is trashed. If you're familiar with digital cameras, if you overexpose a part of the image, it gets represented as "pure white." No amount of playing with curves or other tools will bring back the detail that was there - the information is gone.

If you must use an amplifier for the weak signals, the only one worth considering is the Winegard HDP-269, which isn't supposed to overload like the others do.

If you absolutely had to go the attic route is there a antenna you would reccamend? Thanks

Smaerd58 shouldn't have an overload problem from local analog channels 14 and 27 because they are low powered (11Kw and 81 Kw, and 60 degrees off his Philly boresight.

In desperation, he might go with a CM-4228 and a high gain preamp, and a rotor would be a must for "tweaking:' as may be beneficial. One he determines exactly what direction Philly comes from, he should mast his antenna such that the Philly transmission path avoids any windows, ducts or other metallic or dense parts of his attic.

If you absolutely had to go the attic route is there a antenna you would reccamend? Thanks

The 4228 is the best commercially-made attic antenna, period.

Highly concur, exclamation mark!!!

CM-4228 not only has very high gain, but is also very compact.
Some people have even used them with rotators....

Only the extremely long Yagi's have more gain on the higher channels,
but good luck mounting and carefully orienting one in between rafters.
And forgetabout a rotator....

1) With stations that close, you can't use the 7777. It *will* overload. You shouldn't need amplification for a station 29 miles away, either, unless they're at very low power or are broadcasting from the ground.

2) The problem is that an amplifier isn't a smart device - it doesn't know what signals are strong and what ones are weak. It takes the whole spectrum as input and boosts the waveform.

If you must use an amplifier for the weak signals, the only one worth considering is the Winegard HDP-269, which isn't supposed to overload like the others do.
Thanks for the further explanation, I've got a better handle on what's happening now. I'm going to pull the 7777 off the mask and see if things improve over the 7777 on the mask, but unpowered.

The stations that I'm getting fine are mostly between 4 and 6 miles away, but I'm also getting one that's 22 miles away just fine. I'm trying to get a PBS station that is listed as 29 miles away. It comes in, but the signal level is only about 9 dB and it's not enough for my DTV tuner (a Divco Fusion 5) to grab a consistent picture.

I would have thought that the attenuator (which is adjustable) would have toned down any excessive amplification. And even if the CM 7777 preamp was overloading the local stations, I wouldn't expect it to completely kill the signal on the weak station that I'm trying to get. But then, I'm not that RF knowledgeable.

Sregener thinks that with the CM 7777 un-powered but still in the line, I'm not getting any signal from the antenna....I'm going to take the un-powered CM 7777 out of the loop and see what happens.

Thanks for the suggestions.
With broadcast towers only 4-6 miles away, the CM-7777 is extremely overloaded,
and will prevent reception of the weaker stations, depending on where the intermod products lie...

You should first try moving a high gain antenna (e.g. CM-4228) to different locations to try to optimize reception of distant stations.

If that isn't enough, you could then try the W-G HDP-269 VHF/UHF Preamp.
It is a lower gain Preamp intended for urban applications, with considerably higher overload capability.

BTW: An attenuator to prevent Preamp overload would be used between the antenna and the Preamp.
In very high signal level locations like yours, a second attenuator may be needed on the output of the Preamp
to prevent desensitization of your HDTV's tuner.

I prepared spread sheets to calculate these overload conditions for a similiar situation in Santa Rosa, CA here:
http://hdtv.forsandiego.com/messages/1/2846.html#POST20070

And here is another example prepared for San Diego, CA location:
http://www.avsforum.com/avs-vb/showthread.php?p=6811219&#post6811219

CM-4228 not only has very high gain, but is also very compact.
Some people have even used them with rotators....

Only the extremely long Yagi's have more gain on the higher channels...


The 4228's advantage is that it is already a horizontal and vertical stack. Attics tend to be awash in reflections from everything metal in the attic. The stacks help to drill through that and only lock onto the primary signal. Outdoors, this advantage decreases and yagis can be better. But in an attic, the 4228 is the champion until you do an 8-bay yagi.

I'm getting a 2nd Hdtivo soon. I have a db8 on the roof...20ft down the wire into the attic i have a leviton 25db amp then about 100 ft of wire to the HDtivo. I must have that amp or i can't watch OTA. On the off chance that a cheapo splitter degrades my signal (i AM on the cusp of losing 2 channels as they are only 71 on the meter), what kind of amp could i put behind the tivos to split that wire successfully? (the tivos will be stacked)

i'm worried about 2 amps on the same ota wire

If you absolutely had to go the attic route is there a antenna you would reccamend? Thanks

I would recommend getting 2 Quad-X antennas like the Antennas Direct XG91 series,either in vertical or horizontal stack(you said you had plenty of room).Much better gain and directivity on the higher channels(like 62,64,67,PBS,ABC,NBC) than the 4228,plus,if one or two don't work you can send one or both of them back.In all likelyhood you won't be able to return a 4228.The 4228's performance above Ch60 is mediocre.

My 2 cents

Greg B
Midwest Dxer

I'm getting a 2nd Hdtivo soon. I have a db8 on the roof...20ft down the wire into the attic i have a leviton 25db amp then about 100 ft of wire to the HDtivo. I must have that amp or i can't watch OTA. On the off chance that a cheapo splitter degrades my signal (i AM on the cusp of losing 2 channels as they are only 71 on the meter), what kind of amp could i put behind the tivos to split that wire successfully? (the tivos will be stacked)

i'm worried about 2 amps on the same ota wire

I doubt you'll need another amp.

If you do, use another distribution amp.

Good: CM 3042

Even better: Channelvision CVT15PIA

The other option would be to put a preamp in ahead of the Leviton and move the Leviton down right before the split. I don't know how close you are to your stations, though, and how prone you might be to overload. If you are <30 miles away, you probably should stay with the distribution amp strategy.

I would like to personally thank everyone for their assistance and guidance with my antenna selection process.

Your extra effort in answering my emails has made me more aware of what to look for in an antenna.

I have installed the Dehli VIP-307 (VHF) and the Winegard 9032 (UHF) coupled into the Winegard AP-2870 preamp. (will try the CM 7777 later on, just did not want to overdrive the preamp).

At present, I am thinking adding another 9032 (vertical stack). However, with two 9032's and a VIP-307 on the bottom, I wonder if I will have enough distance inbetween the antennas without interfering with one another. That is the UHF and VHF. In doing some research, you want to have the booms 31.5" away from another with the 9032 stack, or that is 1.5" from the corner reflectors.

So, for the final questions:

1) What is your opinion with stacking the 9032's vertically? Is it woth the effort?

2) Adding the addtional antenna will consume more of the mask, which will not allow 4' inbetween them. Ideas?

Thanks..

I would like to personally thank everyone for their assistance and guidance with my antenna selection process.

Your extra effort in answering my emails has made me more aware of what to look for in an antenna.

I have installed the Dehli VIP-307 (VHF) and the Winegard 9032 (UHF) coupled into the Winegard AP-2870 preamp. (will try the CM 7777 later on, just did not want to overdrive the preamp).

At present, I am thinking adding another 9032 (vertical stack). However, with two 9032's and a VIP-307 on the bottom, I wonder if I will have enough distance inbetween the antennas without interfering with one another. That is the UHF and VHF. In doing some research, you want to have the booms 31.5" away from another with the 9032 stack, or that is 1.5" from the corner reflectors.

So, for the final questions:

1) What is your opinion with stacking the 9032's vertically? Is it woth the effort?

2) Adding the addtional antenna will consume more of the mask, which will not allow 4' inbetween them. Ideas?

Thanks..

Well, there's the rub. A vertical stack may give you increased performance with little extra effort in regards to installation but it all depends on the installation. If you are using a rotor you'll need a guyed thrust bearing with a vertical stack because of the lever arm above the rotator. A horizontal stack will be added effort in installation but can be installed with minimal lever arm above the rotator and also IMO will perform better overall.

If you aren't planning on a rotator and you have plenty of mast space, try the vertical stack. You've little to lose.

I'm assuming you will put the Delhi below and fix it regardless. 60 inch spacing should be sufficient. You can get away with around 48 inches if your emphasis is high band vhf (7-13).

I would recommend getting 2 Quad-X antennas like the Antennas Direct XG91 series,either in vertical or horizontal stack(you said you had plenty of room).Much better gain and directivity on the higher channels(like 62,64,67,PBS,ABC,NBC) than the 4228,plus,if one or two don't work you can send one or both of them back.In all likelyhood you won't be able to return a 4228.The 4228's performance above Ch60 is mediocre.

My 2 cents

Greg B
Midwest Dxer

I am new to this but if these are the channels that I may be able to get
violet - uhf
KYW-DT 3.1 CBS PHILADELPHIA PA 31° 54.9 26
* violet - uhf
WYBE-DT 34.1 PBS PHILADELPHIA PA 31° 54.9 34
* violet - uhf
WPSG-DT 57.1 UPN PHILADELPHIA PA 31° 54.9 32
* violet - uhf
WPVI-DT 6.1 ABC PHILADELPHIA PA 31° 54.9 64

and the antenna you like XG91 series uses UHF channels 14-69 my channels are 3,6,10 etc. will this work? Thanks

Thanks for the further explanation, I've got a better handle on what's happening now. I'm going to pull the 7777 off the mask and see if things improve over the 7777 on the mask, but unpowered.

Holly cow! Sregener was absolutely correct when he said that an unpowered 7777 blocks the signals completely. With the unpowered 7777 preamp, I must have been using just the RG-6 and the metal box of the 7777 itself as the antenna. The asymetrical 7777 box probably accounted for the directional sensitivity I noticed as I rotated the mask.

Taking the 7777 preamp out of the loop, I simply have about 30-35 feet of RG-6 leading to a roof mounted Channel Master 4221A (4 bay bow-tie). And now I get 100% on every digital station, absolutely no problems, from the close-in 4-6 mile stations to the 29 mile station that I was having problems with previously. The improvement is quite dramatic! (I guess that's to be expected when you're going from a length of RG-6 attached to a metal box to an actual antenna!)

My previous antenna was an attic mounted Silver Sensor. Going to a roof-mounted CM 4221A is a very dramatic step up in reception.

Thank you Sregener, cpcat and holl_ands for providing me with a bit of education on RF reception.

I would like to personally thank everyone for their assistance and guidance with my antenna selection process.

I have installed the Dehli VIP-307 (VHF) and the Winegard 9032 (UHF) coupled into the Winegard AP-2870 preamp. (will try the CM 7777 later on, just did not want to overdrive the preamp).

If you're looking for a deal on the CM 7777, I've got a brand new one, used for 1 week (and actually powered for only about 15 minutes of that 1 week). :)

I am new to this but if these are the channels that I may be able to get
violet - uhf
KYW-DT 3.1 CBS PHILADELPHIA PA 31° 54.9 26
* violet - uhf
WYBE-DT 34.1 PBS PHILADELPHIA PA 31° 54.9 34
* violet - uhf
WPSG-DT 57.1 UPN PHILADELPHIA PA 31° 54.9 32
* violet - uhf
WPVI-DT 6.1 ABC PHILADELPHIA PA 31° 54.9 64

and the antenna you like XG91 series uses UHF channels 14-69 my channels are 3,6,10 etc. will this work? Thanks

I tried to explain this once before, but here goes again, in more detail.

Breaking this down, item by item.

"violet" - refers to type of antenna, violet being the largest.
"uhf" - refers to the band the station is broadcasting on, in this case uhf which is channels 14-69.
"KYW-DT" - call sign of the station, with "DT" meaning digital
"3.1" - the virtual channel sent by the station, and what your receiver will display when you tune to this channel.
"CBS" - the network of the station
"PHILADELPHIA PA" - the station from which the signal originates
"31°" - the compass direction (not magnetically corrected) from your location to the transmitter
"54.9" - the distance in miles the signal must travel to reach your address
"26" - the actual physical channel the station is broadcasting on

So to get the stations listed above, you need an antenna that will receive channels 26, 32, 34 and 64.

sregener , that explanation ROCKS ! Cleared it right up for me.I just finished building a HTPC for my living room so this will complete the high def end I hope.I will post what happens as this might help other people.Thanks again,Rick

I am new to this but if these are the channels that I may be able to get
violet - uhf
KYW-DT 3.1 CBS PHILADELPHIA PA 31° 54.9 26
* violet - uhf
WYBE-DT 34.1 PBS PHILADELPHIA PA 31° 54.9 34
* violet - uhf
WPSG-DT 57.1 UPN PHILADELPHIA PA 31° 54.9 32
* violet - uhf
WPVI-DT 6.1 ABC PHILADELPHIA PA 31° 54.9 64

and the antenna you like XG91 series uses UHF channels 14-69 my channels are 3,6,10 etc. will this work? Thanks

You'd probably get more info in the philly thread just FYI. but just wanted to let you know if you have trouble getting abc/nbc (64/67) that in 2009, 67 (nbc10) is moving down to 34 and 34 is moving up to 35. 67 (abc) is moving back to VHF 6. And 54 (wb17) was supposed to go to 17 but i'm pretty sure with CW coming, they are going to still reside at channel 32 (UPN will become cw). I forget the exact details but i'm sure they are in that thread.

My point is, you are farther away than me by 15 miles so you are likely going to have some of the same problems as me. Fox was the absolute worst to pick up but WB and nbc were a close second. I hope you have a very clear line of sight to help you :) good luck

PS i dont know anything about the xg91 but if it can get in vhf 6, you are a long way towards saving yourself another headache in 3 years. I just put up my DB8 and said i'll worry about that later :)

And 54 (wb17) was supposed to go to 17 but i'm pretty sure with CW coming, they are going to still reside at channel 32 (UPN will become cw).

PS i dont know anything about the xg91 but if it can get in vhf 6, you are a long way towards saving yourself another headache in 3 years.

First of all, network affiliation changes will have no impact on what each station's digital allocation will be in 2009. WPHL has elected to move to channel 17, period. WPSG has elected to move to channel 32. Now, if you're concerned about watching WB/UPN programming, what's left of it when CW starts in the fall may be on channel 32 (I haven't followed the affiliate selection for Philadelphia.)

The 91XG is a poor antenna for VHF channel 6. I am within the Grade B contours for a channel 6 analog station and getting the picture to be color is very hard, and getting a clear image is well nigh impossible.

If you scroll down this page, search for "# Y-5-2-6LOW BAND 5 ELEMENT for CHANNELS 2 TO 6" for a solution for channel 6: www.starkelectronic.com/allant.htm

You can combine the two using a simple splitter, or the more expensive Channel Master part #0549.

I don't mind having to mount one on the roof, if need be. I don't want to see these huge rabbit ears sitting atop my beautiful new TV. I tried the Terk HDTVa and it was basically useless.

I'm wondering... Will I typically get as good a result mounting an antenna in my attic as I will strapping it to my chimney? Will the shingles interfere enough to make a difference? Obviously, the antenna in the attic would be less of a chore to install.

Finally, any recommendations for a good make/model antenna? Are some better than others, or are they all about the same? If going the attic/roof route, do I need an amplified one?

THANKS!

Jay

I'm wondering... Will I typically get as good a result mounting an antenna in my attic as I will strapping it to my chimney? Will the shingles interfere enough to make a difference? Obviously, the antenna in the attic would be less of a chore to install.

Finally, any recommendations for a good make/model antenna? Are some better than others, or are they all about the same? If going the attic/roof route, do I need an amplified one?

Jay, you haven't given us enough information to even begin to formulate an answer.

Attic antennas are not recommended, though they do work for many people who are either very close to the transmitters or are just plain lucky. The difference can be significant - 8-12dB is commonly given. 3dB is equal to a doubling of signal strength, so at 12dB, you're talking about letting through less than 13% of the original signal. Will that be enough? It all depends...

If you can provide us your zip code, desired stations, etc., we can tell you more about what antenna to get, and whether you'd want amplification or not. No, they are not all alike. They vary wildly. You didn't really think people put huge antennas on their roof or tower when rabbit ears would have done just as well, do you? ;)

I was just ready to get my CM 4228 and was checking something out on antennaweb and put in my zip 19977 and there are absolutely no Digital stations available for me now. I can only imagine that they decreased the transmission rate because the Satellite companies are now going to have HD locals for like 5.99 which sounds good except you now have to buy new receivers from them for the mpeg 4. And to get the HD locals you have to have a HD package from them as well.Well I guess this is how they are going to pay back themselves for the upgrade.They got me by the short hairs if I want locals with HD. I hope that the telephone company combines there broadband and tv together to compete.Thanks to everybody here,Rick

Jay, you haven't given us enough information to even begin to formulate an answer.

Attic antennas are not recommended, though they do work for many people who are either very close to the transmitters or are just plain lucky. The difference can be significant - 8-12dB is commonly given. 3dB is equal to a doubling of signal strength, so at 12dB, you're talking about letting through less than 13% of the original signal. Will that be enough? It all depends...

If you can provide us your zip code, desired stations, etc., we can tell you more about what antenna to get, and whether you'd want amplification or not. No, they are not all alike. They vary wildly. You didn't really think people put huge antennas on their roof or tower when rabbit ears would have done just as well, do you? ;)
Thanks for your response! My ZIP is 48071 and antennaweb tells me that I'm no more than 10 miles from any of the stations I want to get (basically, all the network stations) and should use a "small multidirectional antenna". I tried that Terk HDTVa and received most of the channels, but they looked less than spectacular (plus, with the antennas extended, the antenna was bigger than my 50" TV -- ridiculous and unacceptable. So that was why I figured I needed something more serious. I'm in a single-story house and that's all I have in my neighborhood, really. Very few trees, too (much to my dismay, where it's not related to TV reception).

Would either of these (1) (http://www.amazon.com/gp/product/B0009W9WHQ/sr=1-4/qid=1144807659/ref=pd_bbs_4/002-9516743-1019252?%5Fencoding=UTF8&s=electronics) (2) (http://www.amazon.com/gp/product/B0006N2PDQ/sr=1-6/qid=1144807713/ref=pd_bbs_6/002-9516743-1019252?%5Fencoding=UTF8&s=electronics) be worth getting? People seem to say that Terk antennas are junk, and I see a lot of people saying they just have old Radio Shack ones that work great. I guess I'd like to somehow figure out which type would be best for me, and then see if anyone has any recommendations of specific units of that type.

Thanks for any insights!

Jay

I was just ready to get my CM 4228 and was checking something out on antennaweb and put in my zip 19977 and there are absolutely no Digital stations available for me now.

Must have been a temporary glitch. I tried it just now and got

WYBE-DT (34.1, 34)
KYW-DT (3.1, 26)
WPHL-DT (17.1, 54)
WPSG-DT (57.1, 32)
WPVI-DT (6.1, 64)

all at 54.9 miles. With the flat terrain you have there, you should have a good chance of getting these with a CM4228 on the roof.

I was just ready to get my CM 4228 and was checking something out on antennaweb and put in my zip 19977 and there are absolutely no Digital stations available for me now. I can only imagine that they decreased the transmission rate because the Satellite companies are now going to have HD locals...

You must have made a mistake, or maybe antennaweb was playing with their forumla. I just did a check and there's four digitals listed for you.

The broadcasters aren't going to reduce power just because the satellite companies are offering their signal. They *want* people to watch their signal, which is why they broadcast it in the first place. Satellite may have some influence, but they don't have the money to convince broadcasters to reduce power. Reducing power would also decrease the value of the broadcaster when they sought to sell, which is not a good thing for them.

You've gotten this far, you may as well give it a try.

I tried that Terk HDTVa and received most of the channels, but they looked less than spectacular (plus, with the antennas extended, the antenna was bigger than my 50" TV -- ridiculous and unacceptable.

People seem to say that Terk antennas are junk, and I see a lot of people saying they just have old Radio Shack ones that work great. I guess I'd like to somehow figure out which type would be best for me, and then see if anyone has any recommendations of specific units of that type.

At 10 miles, you don't want anything that is amplified.

The highest recommended antenna for indoor use is the Zenith Silver Sensor. The Terk HDTVa is similar, except for the amplification.

If you're getting the digital signals, that's the best you can do - the pictures won't look better with a better antenna. If you're still watching the analog ones...

You also don't need to extend the antennas - they're for VHF, and none of your digitals are on VHF.

At 10 miles, you don't want anything that is amplified.

The highest recommended antenna for indoor use is the Zenith Silver Sensor. The Terk HDTVa is similar, except for the amplification.

If you're getting the digital signals, that's the best you can do - the pictures won't look better with a better antenna. If you're still watching the analog ones...

You also don't need to extend the antennas - they're for VHF, and none of your digitals are on VHF.
THANK YOU for the info!! Is this (http://www.amazon.com/gp/product/B00006FXR9/sr=8-1/qid=1144848496/ref=pd_bbs_1/104-0855862-7711913?%5Fencoding=UTF8) the Zenith antenna that you refer to?

The instructions were so poor with the Terk that I had no idea about those extendable antenna arms only being used for VHF -- thanks again! So much useful information in those few lines.

THANK YOU for the info!! Is this (http://www.amazon.com/gp/product/B00006FXR9/sr=8-1/qid=1144848496/ref=pd_bbs_1/104-0855862-7711913?%5Fencoding=UTF8) the Zenith antenna that you refer to?

Yes, that's the antenna. It looks similar enough to your HDTVa that you might be able to get comparable results by turning off the amplification on the one you have. But you'll probably save money with the unamplified version from Zenith.

Yes, that's the antenna. It looks similar enough to your HDTVa that you might be able to get comparable results by turning off the amplification on the one you have. But you'll probably save money with the unamplified version from Zenith.
I tried with and without amplification on the HDTVa (which I returned)... So you figure it's not worth trying one of these? It looks like nobody sells them locally -- I'd like to save on shipping in case it doesn't work out and needs to be returned.

Also, if these types don't work, would you expect that I would have better results with a roof-mounted antenna, then?

Hello all,

I just purchased an HDTV set and connected a TERK HDTVa - Amplified Directional Indoor HDTV Antenna. Although I get all the local HDTV channels (with better results late at night) I'm not 100% pleased with the antenna because of spotty reception and not being able to clearly capture analog feed. So I'm thinking of getting the Winegard Squareshooter SS200 or the Terk HDTV-s.

Anybody have any experience with either of these antennas - are they any good? Also how hard are they to install? I've read where you can mount it to the satellite dish and share the same cable. If I do this installation is it still necessary to ground the antenna?

Any input would be greatly appreciated.

Go with a real antenna....."the uglier, the better" is the saying, although you don't always need something huge, and you don't always need to mount it in the most visible location, either.

If your stations are all UHF, you can get by with something fairly small. A "real" (VHF+UHF) antenna, though, will give you all the existing analog stations, as well as FM reception.

Forget the ones that mount to the dish. They almost always are pointing in the wrong direction, and the metal dish can interfere with reception. Plus, diplexers (for sharing the same cable) aren't the optimal solution.

Use good RG-6/U cable, proper connectors, and be sure to ground the system per the instructions they supply. Main thing is to get it grounded to "earth" and to the same as the house electrical ground, to prevent safety hazards.

Make the coax connections "just beyond finger tight" (being sure the connectors are on straight....watch out on those "D" shaped, and "flat on two sides" connector jacks). Weatherproof everything that's outdoors or in the crawl spaces....tape won't do it, you need something pliable, like RTV or that putty they sell at electronics stores.

Most of the time, a split or two won't hurt. Just get good quality splitters, and make sure the connections are good. For FM, a tap (rather than a splitter) will work to feed the FM receiver....most are far more sensitive than needed. A 12 or 16 dB tap usually is OK. That passes most of the signal on, to the TV, but "taps" a bit off to the FM.

Try to mount the antenna with proper hardware, usually to some solid wall studs or roof joists....don't forget to waterproof the bolt holes.

Radio Shack has many of the cable clamps and stuff, but a trip to a pro Electronics Parts house, like the TV repair guys use, is a good one-stop shopping trip.

None of those antennas are going to reliably receive Columbus, and you will probably find the CM-4221/3021 to be inadequate indoors at 34 miles away.

Antennaweb only shows you being able to reliably receive two nearly DTV stations: i-PAX (10 mi, 181 deg) and PBS (26 mi, 286 deg)....that's with an outdoor antenna on a pole.

It appears that you need an antenna with a significant amount of gain in order to work towards receiving the Columbus DTV group 34 miles away (260 degrees)...

Got the TV last night and the auto setup found :eek: 72 digital channels not on the antenna, but through my basic cable! lol! Granted, about 62 of those are music channels, guess I don't have to worry about messing with an antenna! The only station I don't get is ABC's digital feed, and since I don't watch LOST that's just fine with me! :p It would be nice to get FOX though...

Also, if these types don't work, would you expect that I would have better results with a roof-mounted antenna, then?

Yes. The Channel Master 4221 is the antenna of choice for your range.

I just purchased an HDTV set and connected a TERK HDTVa - Amplified Directional Indoor HDTV Antenna. Although I get all the local HDTV channels (with better results late at night) I'm not 100% pleased with the antenna because of spotty reception and not being able to clearly capture analog feed.
I had similar results w/ the Terk HDTVa -- worthless to me. I'm in the same boat as you, wondering what is my best route now. Some very useful replies have already been posted on roof antennas -- thanks guys!

What does the screen on the back of the antenna do? The reason I asked this question is because it does not fit in my attic rafters. If I remove the screen or cut the top corners of the screen, it will fit. Before I ruin this antenna, I wanted some advice (i.e. to remove or not OR to cut or not). Any thoughts would be appreciated.

I was under the impression that you need an “HDTV” antenna to receive OTA HD programming. According to a thread on this forum this is not the case. With this in mind I currently have an older antenna (at least 8 years old) which is installed on the roof but I have never had to use it because I’ve always had satellite since moving into the house. Now if this antenna can capture digital/analog signals I’d like to put it to use. However my problem is it’s using the older 300-ohm television twin-lead cable. My question is can I replace the twin lead-cable with the newer 75-ohm coaxial cable and if so how hard or difficult would that be?

What does the screen on the back of the antenna do? The reason I asked this question is because it does not fit in my attic rafters. If I remove the screen or cut the top corners of the screen, it will fit. Before I ruin this antenna, I wanted some advice (i.e. to remove or not OR to cut or not). Any thoughts would be appreciated.

The screen serves two purposes by doing the same thing. Signals reflect off of metal that is longer than 1/2 wavelength. Signals coming from behind (usually reflections) bounce back from whence they came, eliminating a common source of multipath and improving the directionality of the antenna for sources behind it. The screen also reflects the signals that pass through the bowtie area, directiong them back at the bowties. For a perfect reflector, this would improve gain by 3dB. The distance is so short from the bowtie to the screen that the two sources appear to arrive at the same time, so there is no multipath there.

Cutting the top corners would be much better than removing the screen entirely.

I was under the impression that you need an “HDTV” antenna to receive OTA HD programming.

However my problem is it’s using the older 300-ohm television twin-lead cable. My question is can I replace the twin lead-cable with the newer 75-ohm coaxial cable and if so how hard or difficult would that be?

'Tain't no such thing as an HD antenna. Antennas receive signals for the frequencies they're designed for. Since analog and digital television in the US are in the same frequency range, almost any "old" antenna will work. I say "almost" because some antennas are VHF-only, and most digital signals are UHF. It is almost certain that you have a VHF/UHF combo antenna that will work fine for both.

No need to replace that cable. Just get a transformer like this one: http://www.radioshack.com/product/index.jsp?productId=2062054&cp=2032057.2032187.2032189.2032207&pg=2&parentPage=family

To receive HD OTA signals what you need is an antenna that works for the frequencies that the stations are transmitting at. The TV band was divided into two basic frequency ranges. VHF which is channels 2-13 and UHF which is channels 14-83. Most, but not all stations transmitting an HD signal are in the UHF band. You will need to check the stations in your area. Antennaweb.com is a good source of that info.

The antenna you need then is either UHF or VHF or both with appropriate gain to bring in the signals from the stations you desire. The more gain the antenna has, the better it will be at receiving signals. Likewise the higher you mount it the better it will operate.

The old 300 ohm flat leadin may be easily replaced by 75 ohm coaxial. What you need is a Balun or impedance matching transformer to convert from the antennas impedance of 300 ohms to the coaxial cables impedance of 75 ohms. This is an inexpensive device available at radio shack and attaches where the old 300 ohm flat leadin attached to the antenna. It has a F connection to attach the 75 ohm coaxial cable to it.

I suggest replacing the cable. 75 ohm coaxial is less susceptable to noise and interference than the old 300 ohm twin lead. The balun shown in the previous post is normally used indoors behind the TV. It is the type you want if you do not replace the existing downlead. The type you want if you replace the downlead with coaxial (RG6) is the outdoor type that attaches directly to the antenna.

Hope this helps.

I was under the impression that you need an “HDTV” antenna to receive OTA HD programming. According to a thread on this forum this is not the case. With this in mind I currently have an older antenna (at least 8 years old) which is installed on the roof but I have never had to use it because I’ve always had satellite since moving into the house. Now if this antenna can capture digital/analog signals I’d like to put it to use. However my problem is it’s using the older 300-ohm television twin-lead cable. My question is can I replace the twin lead-cable with the newer 75-ohm coaxial cable and if so how hard or difficult would that be?

they got you with their advertising. I can't address the 75ohm thing (i'm pretty sure there is an adapter) but do know that it's definitely worth hooking that up to see if it works. There is simply no difference in HD antennas vs others. A 20 yr old antenna in great shape (an unlikely find i know) is just as good as today. Of course there is a difference in VHF and UHF so you must know what channels you need.

And receivers like a hi definition tivo only do get in the digital channels not the analog, but that's a whole different story. The antenna is still picking up analog.

[QUOTE=sregener]'Tain't no such thing as an HD antenna. Antennas receive signals for the frequencies they're designed for. Since analog and digital television in the US are in the same frequency range, almost any "old" antenna will work. I say "almost" because some antennas are VHF-only, and most digital signals are UHF. It is almost certain that you have a VHF/UHF combo antenna that will work fine for both.

No need to replace that cable. Just get a transformer like this one:


Thanks a bunch. I'm going to try that route. I'd prefer not have to change the cable unless it's really necessary or because of bad reception. How hard is it to replace the ends of the twin lead if they break off meaning the ends that would fit into the transformer?

To receive HD OTA signals what you need is an antenna that works for the frequencies that the stations are transmitting at. The TV band was divided into two basic frequency ranges. VHF which is channels 2-13 and UHF which is channels 14-83. Most, but not all stations transmitting an HD signal are in the UHF band. You will need to check the stations in your area. Antennaweb is a good source of that info.

The antenna you need then is either UHF or VHF or both with appropriate gain to bring in the signals from the stations you desire. The more gain the antenna has, the better it will be at receiving signals. Likewise the higher you mount it the better it will operate.

The old 300 ohm flat leadin may be easily replaced by 75 ohm coaxial. What you need is a Balun or impedance matching transformer to convert from the antennas impedance of 300 ohms to the coaxial cables impedance of 75 ohms. This is an inexpensive device available at radio shack and attaches where the old 300 ohm flat leadin attached to the antenna. It has a F connection to attach the 75 ohm coaxial cable to it.

I suggest replacing the cable. 75 ohm coaxial is less susceptable to noise and interference than the old 300 ohm twin lead. The balun shown in the previous post is normally used indoors behind the TV. It is the type you want if you do not replace the existing downlead. The type you want if you replace the downlead with coaxial (RG6) is the outdoor type that attaches directly to the antenna.

Hope this helps.


Thanks a lot it certainly helps. I think i"ll try the indoor balun first and judge if the reception is good if not I guess I'll try to replace the cable. How hard of a job is it? As I'm sure you can tell this is not my forte.

Even if your reception is mostly good but you've got any stations that are just borderline, I'd probably go ahead and change it anyway. And even if the antenna is intact, the connections might not be in such great shape. But you may not have to. Depends on your needs, too, I guess. But if you go all out (RG6 or better, preamp, rotor), you may be able to receive more channels, depending on their locations and distances. (Think of all those channels and free HD, and you can go tell the cable/satellite companies to go stick it!).

Even if your reception is mostly good but you've got any stations that are just borderline, I'd probably go ahead and change it anyway. And even if the antenna is intact, the connections might not be in such great shape. But you may not have to. Depends on your needs, too, I guess. But if you go all out (RG6 or better, preamp, rotor), you may be able to receive more channels, depending on their locations and distances. (Think of all those channels and free HD, and you can go tell the cable/satellite companies to go stick it!).


I'm not totally averse to replacing the 300-ohms flat cable with the coaxial I'm just a little bit apprehensive of whether it's something I'll be able to do. I just went to RadioShack to get the transformer to try Sregener's solution and decided to ask about the outdoor balan which barrygordon alluded to in his post and the guy at Radioshack had no idea what I was talking about. If it's something that just entails unplugging/unscrewing/unhinging the old cable and replacing it with the balan/coaxial cable I'd be more than happy to try it.

Any input or instructions or links to a site that can guide me would certainly be appreciated.

I'm not totally averse to replacing the 300-ohms flat cable with the coaxial I'm just a little bit apprehensive of whether it's something I'll be able to do. I just went to RadioShack to get the transformer to try Sregener's solution and decided to ask about the outdoor balan which barrygordon alluded to in his post and the guy at Radioshack had no idea what I was talking about. If it's something that just entails unplugging/unscrewing/unhinging the old cable and replacing it with the balan/coaxial cable I'd be more than happy to try it.

Any input or instructions or links to a site that can guide me would certainly be appreciated.
You can check out Channel Master's 45 page"Off-Air Antenna Installation Guide":
http://www.channelmaster.com/pdf/AntInstallGuide.pdf

The on-line version (see Chapter 5) is here:
http://www.starkelectronic.com/cmig.htm

Go to a different Radio Shack. That guy was Radio Shack Challenged if he did not know what a 300 to 75 ohm Balun was. Try Radio Shack part # 15-1230.

It involves only the use of a screw driver and most times the antenna connection point (where the 300 ohm lead was attached), has wing nuts.

At the antenna you will detac the 300 ohm lead and attach the Balun/adapter. The other end of the Balun has an F screw connection which will match the connector on the end of the cable. Now you have to attach the cable to the house so it does not fly in the wind and run it to the room you want it to end up in.

The hardest part of the whole job is attaching the wire to the house or fishing it through the walls to get to where you want it to be without the Wife going ballistic.

sregener's R-S link must be messed up.
It is for a Balun which connects downlead coax to a TV that only has twin screw terminals.
Surely your HDTV has a coax input and would not need this type Balun.

Here's the R-S 15-1230 75 to 300-ohm Balun for connecting downlead to TV Antenna:
http://www.radioshack.com/product/index.jsp?productId=2062049&cp=&origkw=15-1230&kw=15-1230&parentPage=search

BTW: The loss in the Channel Master Balun from Fry's is better by about a dB:
http://shop3.outpost.com/product/2570351?site=sr:SEARCH:MAIN_RSLT_PG

=================================================
Could you describe or post a picture of the kind of antenna you have?
As mentioned earlier, you probably want a combination VHF/UHF antenna, although most of the DTV stations today are still on UHF.

sregener's R-S link must be messed up.
It is for a Balun which connects downlead coax to a TV that only has twin screw terminals.
Surely your HDTV has a coax input and would not need this type Balun.

Here's the R-S 15-1230 75 to 300-ohm Balun for connecting downlead to TV Antenna:
http://www.radioshack.com/product/index.jsp?productId=2062049&cp=&origkw=15-1230&kw=15-1230&parentPage=search

BTW: The loss in the Channel Master Balun from Fry's is better by about a dB:
http://shop3.outpost.com/product/2570351?site=sr:SEARCH:MAIN_RSLT_PG

=================================================
Could you describe or post a picture of the kind of antenna you have?
As mentioned earlier, you probably want a combination VHF/UHF antenna, although most of the DTV stations today are still on UHF.




You guys are great! I'm learning so much here. As far as the antenna i'm not sure what brand/type for that matter because as I said it's been in the house since I moved in, at least eight years old but it resembles something like this

http://www.av-outlet.com/media/TV38.jpg

I think this weekend I'm going to try to install the outdoor balun and run the coaxial cable.

If you do need a new antenna, it might be a wise to look into where all your channels might end up after the analog shutoff in 3 years. They most likely won't be in the low/VHF range, but some (like two by me here in Chicago are supposed to) might still be in the high/VHF range, and this will factor into your antenna choice.

If you do need a new antenna, it might be a wise to look into where all your channels might end up after the analog shutoff in 3 years. They most likely won't be in the low/VHF range, but some (like two by me here in Chicago are supposed to) might still be in the high/VHF range, and this will factor into your antenna choice.


That's good to know. I didn't even think of that - I'll keep that in mind.

If you do need a new antenna, it might be a wise to look into where all your channels might end up after the analog shutoff in 3 years. They most likely won't be in the low/VHF range, but some (like two by me here in Chicago are supposed to) might still be in the high/VHF range, and this will factor into your antenna choice.
Where would one look into this? A central source, or would you have to check w/ each individual station?

sregener's R-S link must be messed up.
It is for a Balun which connects downlead coax to a TV that only has twin screw terminals.

Ummm. He's got 300-Ohm downlead. That's aka twinlead. He screws the two pieces into the screws and plugs the 75-ohm connector into his STB or TV. How's my link messed up? Your link leads to a product which not only requires a separate piece of coax from the transformer to the set, but also requires him to fashion a connector to keep the two wires of 300-Ohm connected to the transformer.

300-Ohm is great compared to 75-Ohm for transmission - much less loss than RG-6. But RG-6 is less impacted by noise and interference. But if you're going to try things out, better to try the $5 solution first and see if it works before spending a lot of $$$ and time to replace cables.

If the antenna looks like the one he's listed, he should have no problem with reception under most conditions.

Ummm. He's got 300-Ohm downlead. That's aka twinlead. He screws the two pieces into the screws and plugs the 75-ohm connector into his STB or TV. How's my link messed up? Your link leads to a product which not only requires a separate piece of coax from the transformer to the set, but also requires him to fashion a connector to keep the two wires of 300-Ohm connected to the transformer.

300-Ohm is great compared to 75-Ohm for transmission - much less loss than RG-6. But RG-6 is less impacted by noise and interference. But if you're going to try things out, better to try the $5 solution first and see if it works before spending a lot of $$$ and time to replace cables.

If the antenna looks like the one he's listed, he should have no problem with reception under most conditions.


Sregener your solution worked like a charm. I thank you very much. I'll probably stick with this unless, as I said the reception becomes spotty in the future, but for now it's clear as water.

One question what tool would you use to strip a 300-ohm flat wire in order to possibly extend it because it's too short and the cable is fraying a bit?

sregener's R-S link must be messed up.
It is for a Balun which connects downlead coax to a TV that only has twin screw terminals.
Surely your HDTV has a coax input and would not need this type Balun.

Here's the R-S 15-1230 75 to 300-ohm Balun for connecting downlead to TV Antenna:
http://www.radioshack.com/product/index.jsp?productId=2062049&cp=&origkw=15-1230&kw=15-1230&parentPage=search

BTW: The loss in the Channel Master Balun from Fry's is better by about a dB:
http://shop3.outpost.com/product/2570351?site=sr:SEARCH:MAIN_RSLT_PG

=================================================
Could you describe or post a picture of the kind of antenna you have?
As mentioned earlier, you probably want a combination VHF/UHF antenna, although most of the DTV stations today are still on UHF.


Just follow this link http://homepage.mac.com/gregmac1/PhotoAlbum47.html to see the type of antenna that I have (click on an image to get a better view).

I've attached the pdf file. The tentative channel designation (last column) will be the channel # in 2009.

Anyone looking at an antenna should probably look at there stations to be sure they are all staying UHF before investing in a UHF only solution.

I've attached the pdf file. The tentative channel designation (last column) will be the channel # in 2009.

Anyone looking at an antenna should probably look at there stations to be sure they are all staying UHF before investing in a UHF only solution.
The pdf doesn't work so I don't know what the document says. My understanding is that the government is taking back all the VHF channels for emergency services in 2009.

The pdf doesn't work so I don't know what the document says. My understanding is that the government is taking back all the VHF channels for emergency services in 2009.
PDF opens OK for me... Thanks for posting!

Anyone looking at an antenna should probably look at there stations to be sure they are all staying UHF before investing in a UHF only solution.

I figure that, if necessary, I can add a hi-VHF antenna in 2009. However, my 91XG does a passable job at hi-VHF reception all by itself, and will probably work fine. Many others will find that their UHF antennas do a good enough job to not have to worry about it. (Note that this doesn't apply to the CM7775, which blocks VHF.)

My understanding is that the government is taking back all the VHF channels for emergency services in 2009.

False. Originally, that was the plan, but it changed years ago. Then they were going to sell off 2-6, but the stations balked and the DTV core is defined as channels 2-51.

My understanding is that the government is taking back all the VHF channels for emergency services in 2009.

I've heard this also. However, an engineer at one of my local stations confirmed they will be going back to channel 5 with digitall when analog goes dark.

I figure that, if necessary, I can add a hi-VHF antenna in 2009. However, my 91XG does a passable job at hi-VHF reception all by itself, and will probably work fine. Many others will find that their UHF antennas do a good enough job to not have to worry about it. (Note that this doesn't apply to the CM7775, which blocks VHF.)

You should probably mention that this may require a rotor for off-axis aiming. UHF yagi/corner reflectors are only decent for high vhf off-axis and "through the back" in my experience. Bowtie antennas do seem to have usable gain on-axis for high vhf.

False. Originally, that was the plan, but it changed years ago. Then they were going to sell off 2-6, but the stations balked and the DTV core is defined as channels 2-51.
Does that mean DTV is giving back 52-69 when that occurs?

The US has it very good compared to the UK. They lost their VHF channels quite a few years ago and have been broadcasting both analog and digital (they went very digital in the late 90s) on the UHF band spectrum (8 MHz bands instead of 6 MHz) and only have channels 21-69. They want to start OTA HD transmissions but do not even have one 8 MHz band available and the government wants the analog channels back when analog transmission ceases in 2012.

Yes!

You should probably mention that this may require a rotor for off-axis aiming. UHF yagi/corner reflectors are only decent for high vhf off-axis and "through the back" in my experience. Bowtie antennas do seem to have usable gain on-axis for high vhf. That's because of the length of the antenna when turned sideways, or the longer elements being in the forefront when backwards. I know that even with my little Silver Sensor, I can receive high/VHF channels not too bad that way at times. But I think the distance and signal strength make a difference, too.

Direct Tv just did an off air antenna install job at my parents house. I don't know the name of the antenna, but it is a small directional outdoor antenna that looks like a thick saucer. According to antennaweb.org, the house needs a light green antenna (small directional antenna with a pre-amp) to get the locals. The antenna alone is not getting any signals. I am considering going to Radio Shack in the morning and hooking up a pre-amp. This is where I am lost. What is a recommended pre-amp at Radio Shack? Do I just hook it up inside near the input of the HD DVR for it to function properly? Do you think I am on the right path of even trying this out? For what it is worth, the stations are in the Huntsville, AL area and my parents live in Decatur, AL (35603).

No pun intended, but thanks for any direction you can give me on this subject!!

Direct Tv just did an off air antenna install job at my parents house. I don't know the name of the antenna, but it is a small directional outdoor antenna that looks like a thick saucer. According to antennaweb.org, the house needs a light green antenna (small directional antenna with a pre-amp) to get the locals. The antenna alone is not getting any signals. I am considering going to Radio Shack in the morning and hooking up a pre-amp. This is where I am lost. What is a recommended pre-amp at Radio Shack? Do I just hook it up inside near the input of the HD DVR for it to function properly? Do you think I am on the right path of even trying this out? For what it is worth, the stations are in the Huntsville, AL area and my parents live in Decatur, AL (35603).

No pun intended, but thanks for any direction you can give me on this subject!!
If you need an amp, how do you know? What will your reception look like before and after amplification? Will it look grainy before, and more crisp after? I am only 10 miles away from my stations and just bought a $20 (unamplified) Radio Shack antenna. My local stations come in pretty good, but they are not absolute perfection -- they are often grainy, and fonts don't look as perfect and crisp as, say, they would on a computer. Is this about as good as it gets for TV? I thought HD broadcasts would be 100% perfection, but my knowledge is obviously lacking. Thanks for any insights!

Before amplication, I am not getting any signal. So ANY reception is what I am seeking! In your case, I think a lot depends on the quality of the specific broadcast.

Just follow this link http://homepage.mac.com/gregmac1/PhotoAlbum47.html to see the type of antenna that I have (click on an image to get a better view).
Yup, it's a combination VHF/UHF antenna, but it's optimized more for VHF than UHF.
The UHF section is the big fat bowtie element, the two small directors and some reflector elements.

You'll just have to see if UHF reception is adequate....
If not, you could consider an upgrade to a more powerful UHF or VHF/UHF combo antenna.

I've attached the pdf file. The tentative channel designation (last column) will be the channel # in 2009.

Anyone looking at an antenna should probably look at there stations to be sure they are all staying UHF before investing in a UHF only solution.
Here is the DTV Channel Election List, conveniently ordered by City/State:
http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-05-1743A2.pdf

Direct Tv just did an off air antenna install job at my parents house. I don't know the name of the antenna, but it is a small directional outdoor antenna that looks like a thick saucer.

Have them call DirecTV and insist they come back and put up a better antenna. There's no excuse for using that antenna.

A preamp is likely to cause more problems than it solves for you with that antenna. A better choice would be to buy a Channel Master 4221 and put that up. I've seen AntennasDirect DB2's on the J-mount poles, and that would probably work great, too, though it is a little more expensive.

My local stations come in pretty good, but they are not absolute perfection -- they are often grainy, and fonts don't look as perfect and crisp as, say, they would on a computer. Is this about as good as it gets for TV? I thought HD broadcasts would be 100% perfection, but my knowledge is obviously lacking.

Picture quality will vary by program source and station. Likely you're looking at upconverted SD when it looks grainy or not crisp.

HD isn't 100% perfection. It's compressed using a lossy format, and often decompressed and recompressed at the station before being sent to you. Still, it can be jaw-dropping when it's done right.

Have them call DirecTV and insist they come back and put up a better antenna. There's no excuse for using that antenna.

A preamp is likely to cause more problems than it solves for you with that antenna. A better choice would be to buy a Channel Master 4221 and put that up. I've seen AntennasDirect DB2's on the J-mount poles, and that would probably work great, too, though it is a little more expensive.

Time is important here. I leave tomorrow and I won't be back for a few months. So if a preamp is not recommended, is there an antenna I can buy at Radio Shack (15-2160?) that might have a good chance of working? Also, if I do go with a different antenna, can I use the same mount the installers used?

I'm within about 6 miles of the towers I want to receive, and their directions vary from 66 to 341 degrees. I can receive analogue broadcast almost on a paper clip. HDTV is another thing entirely. I use a Silver Sensor, and it works ok in the winter when there are no leaves on the trees, unless it's windy. From day to day, the best aim for a given station will vary as much as 180 degrees, and with leaves on the trees, HDTV is just impossible. I've tried the antenna in the attic, and also, outdoors, but at ground level. There is no discernable improvement for either. My house is surrounded with very tall and close-by trees. There is no way I'd get high enough, even with a tower, without putting a red light on top to warn aircraft. I've thought about a CM 4221 or 4228 in the attic to see whether tighter directionality might help, but I'd need a rotator, and I'm not certain the Silver Sensor hasn't just as tight an angle of reception. Any ideas (other than cable)?

Time is important here. I leave tomorrow and I won't be back for a few months. So if a preamp is not recommended, is there an antenna I can buy at Radio Shack (15-2160?) that might have a good chance of working? Also, if I do go with a different antenna, can I use the same mount the installers used?

That antenna is worlds better amd ought to work. Without seeing the mount, I have no idea if it is strong enough or able to get the antenna far enough away from the dish.

That antenna is worlds better amd ought to work. Without seeing the mount, I have no idea if it is strong enough or able to get the antenna far enough away from the dish.

Well I ran out to Radio Shack and tried it. Hooked it up in the living room and it picked up everything it was suppose to. Worked out great!

Picture quality will vary by program source and station. Likely you're looking at upconverted SD when it looks grainy or not crisp.

HD isn't 100% perfection. It's compressed using a lossy format, and often decompressed and recompressed at the station before being sent to you. Still, it can be jaw-dropping when it's done right.
Ok, so it sounds like I'm seeing what I should be seeing then... Thanks! It's definitely a huge improvement over what most of my cable channels look like on this new 50" TV.

general comment: if you have directv (not sure it's true for other providers), locals SD OTA are better than the satellite SD locals. I record everything possible OTA, regardless of SD/HD.

That would work only if the VHF/UHF Joiner and the JoinTenna have DC PASS capability on the ports going to the Preamp.

Does anyone know if the JoinTenna has DC PASS capability on one or both ports???
You can check with a Volt-Ohm-Meter...

I just checked a couple of 0585-2 jointennas (for channels 30-50) and they each had light-gauge inductor coils on the center conductor paths that measured less than one ohm of DC resistance and would have no trouble carrying preamplifier current, and the resistance between the center conductor and ground was over 2Meg, so the only important application detail would be to put a DC block on the input that doesn't have a preamplifier on it.

Some U/V joiners pass power on the V leg and others on the U, but I don't think I've seen one where it was marked on the outside of the case that it passed on both.

I just want to think everyone in this thread for helping me with my antenna installation! I am about 25 miles west of DC and am about 45 miles southwest of Baltimore (they are about 40 degrees difference). Thanks to the advice in this forum, I am using a CM 4221 that is pointed midway between DC and Baltimore. I also added a CM 3041 pre-amp that I bought at Lowes. I have the antenna split to 3 separate receivers (a Sony HDD500 and two Voom receivers). I now get all the DC stations very solid and also get the Baltimore stations solid with occasional breakups.

It turns out that the 4221 had sufficiently wide coverage to capture the two cities despite being 40 degrees apart (I understand that the 4228 is much more directional). Also, the 3041 made a huge difference in terms of both capturing the further Baltimore stations and also getting a strong lock on the DC stations when the antenna is pointed in between the two locations. I used the 3041 primarily because I was somewhat skeptical that the pre-amp would help so I wanted to be able to return it easily. It turned out to be a big help!

Hi there. New to the forum, and just got my first HD set (the Sony 40" Bravia XBR LCD). Love it so far, and have DirecTV scheduled to upgrade my SD TiVo to an HD version on Thursday. They'll also install an OTA antenna. I have some questions about OTA reception.

FYI, my location is Baltimore, MD 21224. This is a city location -- a row house among a sea of row houses -- less than two miles from downtown, and not far from a number of local towers (which sucks for FM DXing, which I also like to do at times).

I've toyed with feeding my FM antenna to the new HD TV and gotten pretty good results. The antenna I'm using is a monster -- it's the Antenna Performance APS-13. I can't post URLs yet, but Google "APS-13" and it's the first link that comes up.

It's great for FM, needless to say. It's tuned ONLY for FM, and is most definitely NOT a TV antenna, much less a UHF TV antenna. I don't intend to use this as my OTA HD antenna (I can't anyway -- I use it with a rotor for FM, and would be moving it around too often.) Still, it gets all Baltimore and nearly all Washington, DC DTV channels (from DC I can't get 20's HD signal if there is one, nor can I get MHz Networks no matter how hard I try). Occasionally Baltimore's 54 DTV signal drops out, but in general it's fine also. Oddly, it doesn't much matter what direction the antenna's pointing, probably because the antenna was never meant for TV in the first place.

My dish is located on the second floor deck, which puts it roughly 15 feet above the 82 feet above sea level altitude of my house (according to Google Earth, anyway) -- close to 100 feet above sea level. The APS-13 antenna is up on the roof, about 10 feet above the roof surface when you factor in the two five-foot masts, making the antenna itself roughly 115 feet above sea level.

I'd like to know what kind of reception I can expect from DirecTV's provided OTA antenna. It'll be at a lower height than the APS-13, but then again, it'll actually be made to pick up TV signals. It won't have the expansive line-of-sight reception the rooftop antenna has, either. But I'm wondering -- since the dish happens to to point very close to the same direction as Washington, DC, will this aid in picking up DC's HD signals?

Second, say I can get DC's HD signals OTA. Now, I know the DirecTV HD DVR lets you add your OTA signals into the program guide, making it available for recording programs, seeing program listings, etc. Does this box allow me to program in BOTH Baltimore and DC channels in the program guide -- i.e., whatever I can pick up, it'll list in the guide?

And third . . . can the OTA antenna that DirecTV installs "ride" on top of one of the coaxes currently running from the dish into the house? I'm not too keen on the idea of fishing yet ANOTHER cable down through the basement crawl space, into the finished portion of the basement, into the drywall, and up into the living room.

Thanks in advance for any help you can offer on the 4,396 questions above. Look forward to the answers!

I can help with just a few things.

Yes you can diplex the OTA on the same lines as HDtivo.

yes there is a secondary selection for your other market to be included in the directv guide.

my guess is so close to the towers, you may need to crank down that signal a bit if you have problems. I dont know anything about directvs antenna though sorry. If you are getting it free, can't hurt to try it, but if it doesnt work, and you paid for it, be sure to get your money back.

You may have better luck with area specific questions in the HDTV thread for DC/Balt.

enjoy the hdtivo! I love my 2 units and the ota pic.

Well, I guess it's finally happened. Some 4,400 posts later, every question that can be asked has been asked and answered a dozen times. We can all go home now.

Well, I guess it's finally happened. Some 4,400 posts later, every question that can be asked has been asked and answered a dozen times. We can all go home now.

I think it would be nice if you could summarize them into a FAQ :)

So what kind of antenna do you recommend for me? I live in a house, on land, with windows, a roof, a spa, and even have some grass.... and dont want anything ugly :)

or able to get the antenna far enough away from the dish.
Your 'far enough away from the dish' makes me consider my large ch 3 only antenna for Roanoke PBS. It sits above my dish - about 2 feet - and its elements extend over it. This is still my most troublesome channel ( my UHF antenna is about 4 feet above it)
I could move just the ch 3 antenna horizontally about 5 feet away to the other side of the chimney.
Is the dish possibly having a negative effect on the antenna? Worth a try?
Thanks,
Bernieoc

Is it easy to move? If so, i'd try it. The other thing some people have trouble with is those rotating fans that stick out of the attic. Creates all sort of multipath havoc but only when the wind blows.

Quote:"I'm within about 6 miles of the towers I want to receive, and their directions vary from 66 to 341 degrees. I can receive analogue broadcast almost on a paper clip. HDTV is another thing entirely. I use a Silver Sensor, and it works ok in the winter when there are no leaves on the trees, unless it's windy. From day to day, the best aim for a given station will vary as much as 180 degrees, and with leaves on the trees, HDTV is just impossible. I've tried the antenna in the attic, and also, outdoors, but at ground level. There is no discernable improvement for either. My house is surrounded with very tall and close-by trees. There is no way I'd get high enough, even with a tower, without putting a red light on top to warn aircraft. I've thought about a CM 4221 or 4228 in the attic to see whether tighter directionality might help, but I'd need a rotator, and I'm not certain the Silver Sensor hasn't just as tight an angle of reception. Any ideas (other than cable)?"

Since I've not received any reply to this, I thought I'd try once more.

Dan,
Give us your zip. From your description it sounds like a rotor or multi-antenna setup is needed.
....jc

I've thought about a CM 4221 or 4228 in the attic to see whether tighter directionality might help, but I'd need a rotator, and I'm not certain the Silver Sensor hasn't just as tight an angle of reception. Any ideas (other than cable)?"

Both the 4221 and 4228 are dramatically more directional than the SS. I'd give the 4228 on a rotor a try, either in your attic or outside.

However, wind can be a major problem with trees, as they can wildly vary the strength of the signal hitting any antenna, and the automatic gain control just can't keep up with the rapid changes.

Paradoxically, you may get better results with a simple bowtie from Radio Shack (runs about $5.) Their return policy makes it easy to try things out and see if it helps.

Dan,

Your location is very similar to mine. Here in Indy I am located 3 miles from one of my local towers and 5-6 miles from most of the others. Four years ago I first tried the CM 4221 which was really bad with multipath. In fact, the multipath was so bad on one station that the receiver indicated "0" signal. I then tried the CM 4228 and that particular station came in just fine. These tests were with the antennas mounted outside, along with a rotor. I also tested them in the attic, but I never could find a location and azimuth where all stations would come in correctly. It can be done in the attic, but it can be very frustrating getting the right setup.

BTW, thanks to some strong tropospheric enhancement in the area earlier this morning, I enjoyed watching your local Detroit news on WJBK-DT 58 for about 30 minutes.

Steve

Quote:"I'm within about 6 miles of the towers I want to receive, and their directions vary from 66 to 341 degrees. I can receive analogue broadcast almost on a paper clip. HDTV is another thing entirely. I use a Silver Sensor, and it works ok in the winter when there are no leaves on the trees, unless it's windy. From day to day, the best aim for a given station will vary as much as 180 degrees, and with leaves on the trees, HDTV is just impossible. I've tried the antenna in the attic, and also, outdoors, but at ground level. There is no discernable improvement for either. My house is surrounded with very tall and close-by trees. There is no way I'd get high enough, even with a tower, without putting a red light on top to warn aircraft. I've thought about a CM 4221 or 4228 in the attic to see whether tighter directionality might help, but I'd need a rotator, and I'm not certain the Silver Sensor hasn't just as tight an angle of reception. Any ideas (other than cable)?"

Since I've not received any reply to this, I thought I'd try once more.

I live surrounded by tall trees, a large multi-story structure cuts off about 20 degrees of my horizon, and there is a small ridge between myself and the majority of the STL towers (ranges 3-10 miles, spread out over 74 degrees of horizon). To get a constant signal above 75%, I had to mount an outside antenna. Welcome back to the 1950's. Please remember that the FCC mandated coverage assumes an antenna 9 meters/30 feet above ground . City grade coverage is assumed reception 90% of the time at 90% of locations, assuming an outdoor antenna at 30 feet. For those of you playing along on our home game, that's an 81% reliability...hence, dropouts.

You don't want to know about Grades A and B coverage. This is why antennaweb is so conservative. The true case for a maxed ERP at the xmtr is to flood the ground coverage, penetrating inside structures, and filling "holes".

I would say that the CM 4221, mounted outdoors, might be your best solution. At the close ranges for your towers, you might get enough signal off the back side of the antenna to allow you to dispense with a rotor (ah hate 'em). The Radio Shack U 75R (http://www.radioshack.com/product/index.jsp?productId=2103088&cp=2032057.2032187.2032189.2032205&parentPage=family)
is rediculously simple to mount, and might work well.

In any case, point the antenna at the "preponderance" of staions for your first try.

Dan,

Update on CM 4221: I finally found the link I was looking for from HDTV Primer regarding multipath. I too found this to be true about this antenna. I live in a fairly wooded subdivision and deal with a lot of leaves.

http://www.hdtvprimer.com/ANTENNAS/cm4221.html

Steve

Here's something that worked for me today.

I was called to service the analog master antenna system for a residential unit on the sixth floor of a twelve story highrise building in McLean VA, about ten miles to the west of the Washington, DC tower cluster. This resident had been using the master antenna system for reception for her old, 25" TV, but now she just bought a plasma TV and decided to go with Cox cable, but the Cox technicians failed on two trips to figure out how to get their signal into this unit (it is post-wired for cable using cove moulding in the hallways) and in trying to figure out how to do it, they inadvertently disabled the master antenna signal, so this disgruntled resident had no TV signal at all.

Well, apparently, the master antenna input coax is now lost inside the wall, and so I told the manager to give notification to the unit above this one so I could fish a new wire down, but in the mean time, I took an 8 foot piece of coax, put an F connector on one end and stripped the other end to expose six inches of bare semiconductor on the other end, and tacked it to her living room wall, at about five feet above the floor. Using the cheap, internal tuner in the TV, she gets rock solid Washington, DC, NBC, ABC, CBS, Fox, WB and Univision, Baltimore WB (Catonsville, MD, actually, and it carries some geezer video service called "The Tube" on its .3 subchannel) and Falls Church Public TV, and tolerable Baltimore NBC and Fox (tiny glitches, here and there).

Not bad for an overlength coat hanger. And her unit is at the western end of the building, meaning that the Washington, DC signals travel through over 500 feet of highrise building. If they were all this easy, I'd have to find another way to make a living.

[QUOTE=AntAltMike]Here's something that worked for me today.

I took an 8 foot piece of coax, put an F connector on one end and stripped the other end to expose six inches of bare semiconductor [/on the other end, and tacked it to her living room wall, at about five feet above the floor.

That was some strange RG-6 coax You used there, I must have been the bare [I]semiconductor ;) that did the job.

wb

Oops! centerconductor

"Someone offered me a hundred thousand dollars to go to bed with him. That's a tenth of an Indecent Proposal.

I'd be a semi Demi Moore.

Or a se-mi', De-mi'!"

- Ellen Degeneris

Well, I guess it's finally happened. Some 4,400 posts later, every question that can be asked has been asked and answered a dozen times. We can all go home now.
Not so fast, i have a problem no ones asked yet. I subscribed with the power company for some of their "free electrons" but they keep charging me. anyone ran into this before?

I never understood whether the "oxygen free" copper conductors in Monster Cables were free of oxygen, or if they gave you the oxygen without charging any extra for it.

"You buy the Stars, the holes are free!"

- The Wizard Of Oatz, who makes the holes in the middle of Kellog's, Lucky Stars, the, "toasted oat cereal with the hole in the middle and the sugar on top".

> do you see any interference/intermod effects from the local Toledo stations?

What does intermod look like? Is there an example online?

> I think the stacked bowtie design is wonderful for people who need high gain and
> a relatively wide angle of acceptance. This is almost always the case in attics.

Why would attics need a relatively wide angle of acceptance?

} Bowtie designs work better in attics than yagis.

Why?

In message 2433, Bob Chase of KHWB-TV writes:

> This phenomenon is called differential gain error because the antenna has
> different gain on different frequencies within the channel.

Is this problem about the same regardless of transmission frequency?
That is, would the magnitude of the problem be the same for channel 2
and channel 51?

> Every antenna has it, some worse than others.

Is data on this available somewhere on the FCC website, or would we
have to ask an engineer at each nearby station?

> It is hard for a DTV tuner to put this back together because there is not
> enough equalization available to reassemble the ATSC data. If we were
> looking at a spectrum analyzer the signal would have huge notches in it
> like the worst multi-path you ever saw.

Are there artifacts of this in a NTSC picture?

What would symptoms be for ATSC tuners? Inability to hold onto a lock?
Dropped packets?

Do some ATSC tuners (perhaps newer generation) do a better job than others?
Perhaps some have more equalization available than others?

> My bet is your are quite correct in that low gain antennas will out perform
> the high gain ones.

Because?

Would one type of receiving antenna (bowtie, Yagi-Uda, parabolic, log-periodic, ...)
be better than another?

> I think the stacked bowtie design is wonderful for people who need high gain and
> a relatively wide angle of acceptance. This is almost always the case in attics.

Why would attics need a relatively wide angle of acceptance?

} Bowtie designs work better in attics than yagis.

Why?
1. An 8-Bay antennas is much more compact than a Yagi with more or less equivalent gain and front/back ratio.
That means it has much more flexibility to be mounted in a favorable location in the attic and can even be used
with a 360-degree rotator to tweak sidelobe nulls towards undesired multipath and interference.

2. High above the roof, static multipath patterns are found:
http://www.hdtvprimer.com/ANTENNAS/siting.html
Attics have lots of nearby objects that cause even more complex multipath reflections.
An 8-Bay antenna has many receiving elements distributed in space.
This means that some of the elements may be in signal maxima, while others are in minima. Big advantage for the 8-Bay.

3. I would expect that a long Yagi antenna is adversely perturbed by the nearby attic structures
more than the 8-Bay, although I haven't seen any NEC simulations on this aspect.

==================================================
An antenna with a wide degree of acceptance is an entirely separate issue, unrelated to whether it is located in the attic or not.
In general, a wide degree of acceptance also means more interference and multipath.
The very wide beamwidth of the 4-Bay antenna is only an advantage when arrival directions are more than
about 15 degrees apart (and less than about 60 degrees).
However, the 4-Bay is very inexpensive and would be my first choice for attic use where the additional gain of the 8-Bay is not needed.

> An 8-Bay antenna has many receiving elements distributed in space.
> This means that some of the elements may be in signal maxima, while
> others are in minima. Big advantage for the 8-Bay.

[ pseudo url due to 5 post restriction ]
hdtvprimer
ANTENNAS
types.html

says:

The formula for the aperture area of any TV antenna is
A=Gl^2/4p
where l is the wavelength and G is the gain factor over an isotropic
antenna (not dB).

(I don't see an explanation for what p is supposed to be. pi?)

So the aperture of the antenna depends on the gain, rather than the
architecture. For example, the 91XG is generally considered to have
about the same performance as an 8-bay bowtie. Thus it should have
about the same aperture.

The 8-bay bowtie would have an advantage in that if you have a gable
facing the transmitters, you could place the 8-bay very close to the
outside wall. This should decrease the reception of reflections
from within the attic. The Yagi-Uda's dipole must be well back from
the outside wall, which might admit more reflections? On the other
hand, if you have a very low pitched roof, the Yagi-Uda might have
the advantage?

So the aperture of the antenna depends on the gain, rather than the architecture. For example, the 91XG is generally considered to have
about the same performance as an 8-bay bowtie. Thus it should have
about the same aperture.

The 8-bay bowtie would have an advantage in that if you have a gable
facing the transmitters, you could place the 8-bay very close to the
outside wall. This should decrease the reception of reflections
from within the attic. The Yagi-Uda's dipole must be well back from
the outside wall, which might admit more reflections? On the other
hand, if you have a very low pitched roof, the Yagi-Uda might have
the advantage?

The problem is multipath, not aperture. And there really is no big advantage to being closer to the outside wall, as all the losses occur in the materials, not in the free space behind it. In fact, since reflection strength diminishes exponentially with distance, being further from the walls may be an advantage. What happens is that all the metal in the attic (ducts, wires, nails, etc.) act as reflectors, bouncing signals around. Inevitably, some of those signals bounce towards the active elements of the antenna.

In the case of a yagi, which has exactly one active element, the multipath signals will hit the active element and be transmitted down the cable to the tuner. However, in a stack such as a bowtie antenna, you have multiple active elements, typically 4 or 8. What this does is create an additive effect for signals that strike all the elements simultaneously, and a negative effect on signals that strike them at different moments. Because the elements are arranged in a plane, only signals coming perpendicular to that plane experience the additive effect. Signals from above, below, or to the side hit different elements at different times, making them relatively weaker compared to the primary signal.

You could create the best of both worlds if you had a large enough attic by stacking four or eight yagis. This would get the better gain of the yagi combined with the multipath resistance of the vertical and horizontal stacks. I suspect that a stack of yagis would outperform a stack of bowties, even in an attic.

I just had a new roof installed and decided to upgrade from my RS VU-120XR antenna in the process. I initially decided to go with an XG91, as my main concern is receiving local HD channels that are all broadcast on the UHF band in my area. But, the more I read about the impending change in frequency of some stations to the VHF band in 2009, the more I'm thinking about going with a VHF/UHF combo antenna instead. But, looking at the gain comparisons on the infamous HDTV primer comparison (see link), the XG91 appears to have more gain in the VHF band than any VHF/UHF combo antenna tested, like the CM3018 for example. Does the XG91 provide good VHF reception? (I understand it's superb for UHF, which is what it's designed for.) If so, why isn't this fact promoted? The XG91 is relatively small and light compared to the top VHF/UHF combo antennas, which are significant advantages for aesthetics and wind shear. Thanks in advance.

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

The problem is multipath, not aperture. And there really is no big advantage to being closer to the outside wall, as all the losses occur in the materials, not in the free space behind it. In fact, since reflection strength diminishes exponentially with distance, being further from the walls may be an advantage. What happens is that all the metal in the attic (ducts, wires, nails, etc.) act as reflectors, bouncing signals around. Inevitably, some of those signals bounce towards the active elements of the antenna.

In the case of a yagi, which has exactly one active element, the multipath signals will hit the active element and be transmitted down the cable to the tuner. However, in a stack such as a bowtie antenna, you have multiple active elements, typically 4 or 8. What this does is create an additive effect for signals that strike all the elements simultaneously, and a negative effect on signals that strike them at different moments. Because the elements are arranged in a plane, only signals coming perpendicular to that plane experience the additive effect. Signals from above, below, or to the side hit different elements at different times, making them relatively weaker compared to the primary signal.

You could create the best of both worlds if you had a large enough attic by stacking four or eight yagis. This would get the better gain of the yagi combined with the multipath resistance of the vertical and horizontal stacks. I suspect that a stack of yagis would outperform a stack of bowties, even in an attic.

It doesn't matter that the directors in a Yagi aren't "driven" elements, they direct the signals that they recieve to the driven element much like if they were wired to it. The directivity of an antenna and the spatial extent of an antenna are directly related (as in by the Fourier transform of the aperture function): a big aperture means a small beamwidth. A Yagi has an oval effective aperture where the vertical and horizontal directivities are similar. A bowtie stack can have different horizontal and vertical directivities. The 4221 has much more vertical than horizontal directivity for instance. I expect that the worst attic multipath effects are mitigated mostly by vertical directivity which would explain why 4 bay high bowtie stacks work well in attics.

So the aperture of the antenna depends on the gain, rather than the
architecture. For example, the 91XG is generally considered to have
about the same performance as an 8-bay bowtie. Thus it should have
about the same aperture.

You're on the right track. The stuff about multiple elements rejecting multipath from the other posters is totally unfounded. Just look at the patterns of the XG91 compared to the CM4228.

http://www.hdtvprimer.com/ANTENNAS/cm4228.html

http://www.hdtvprimer.com/ANTENNAS/XG91.html

The CM4228 has huge sidelobes at around 33 degrees off axis, while the XG91 has a much cleaner pattern. If the multipath just happens to be at 33 degrees, the XG91 will provide a better signal.

Ron

Does anyone know if the HDTV Primer modeling even attempts to take into account the fact that off-axis signals hit the two 4-bay bowtie stacks in 8-bay bowtie antennas at varying phase relationships when it calculates its off-axis gains, or does it just linearly add the calculated signals from the two stacks? Enquiring minds want to know.

I doubt that vertical multipath is any more of a problem in an attic than it is on a flat roof with the antenna in the middle, which is the most common situation I have since I work primarily on highrise buildings with the antennas in the middle of flat roofs. If vertical reflections were a problem, I would commonly see ghosts on my analog signals, since visible ghost images are developed at unintended-to-intended signal ratios that would be too puny to impede digital signal quality. But when I do have a ghost image on a flat rooftop or in an attic, I never am able to minimize it by vertically raising or tilting the antenna, whereas I can affect its intensity by turning the antenna horizontally. I therefore doubt that vertical reflections are relatively significant either on a flat roof or in an attic.

When I installed a lot of residential UHF antennas five or six years ago, I always tried big Yagis first, mostly PR-9022s and 9032s, because they are what had worked well for me in analog applications, but like so many other people contributing to this forum, I came to realize that the junky-looking Channels Master multibay bowties consistently outperformed them in attic applications. I guess that the phase inefficiency of off-target signals is part of what makes them perform better than I would have expected, but that can't be all of the explanation, or even most of it, because I do a lot of installations in metropolitan situations where there are significant angles between the local towers, and theoretically, the horizontally stacked multibay antenna would be poorly suited to that application. The other factors are that the Channel Master bowties have a denser reflector, which helps the F/B ratio at lower frequencies, and the other thing is, since the extent to which the density of the irregular roofing materials varies abruptly, then of the four or eight unique signal streams that hit the separate, active elements of multi-bay bowties, the stronger ones are also the better quality ones.

then of the four or eight unique signal streams that hit the separate, active elements of multi-bay bowties, the stronger ones are also the better quality ones.
That is exactly the wrong way to visualize how an antenna works. The correct way is to visualize the antenna as a composite with a specific current magnitude and current direction developed on each part of the physical structure. The magnitude and direction vector of these currents creates a wave-front aperture which is realized as the directional pattern of the antenna.

This is exactly what the modeling program does. It breaks the antenna up into segments (the more segments, the better the simulation), and computes the current distribution of each segment. Then the composite of all the segments is used to generate the directional pattern (and gain, which is just a function of directivity).

https://ewhdbks.mugu.navy.mil/ANTENNAS.HTM

http://www.borg.com/~warrend/guru.html

Ron

But, the more I read about the impending change in frequency of some stations to the VHF band in 2009, the more I'm thinking about going with a VHF/UHF combo antenna instead. But, looking at the gain comparisons on the infamous HDTV primer comparison (see link), the XG91 appears to have more gain in the VHF band than any VHF/UHF combo antenna tested, like the CM3018 for example. Does the XG91 provide good VHF reception?

I think you're misreading the chart. I don't see any VHF gain numbers for the 91XG on that page.

I do, however, have a 91XG and it is connected to a 19dB VHF preamp. I had a Winegard HD8200P in the same location, with the same preamp, before I bought the 91XG, so I think I can do a fair comparison.

The 91XG has pretty good hi-VHF (channels 7-13) performance. It is not as good as the 8200P. It also needs to be "misaimed" for optimum results. In other words, if you're not using a rotor, I wouldn't use the 91XG for hi-VHF reception. I have a variety of stations in a variety of directions. The closest station (all of these are analog at this point), at 30 miles, comes in almost perfectly with the right aim. There's a hint of ghosting, and minimal impulse noise. I also get a station that is about 60 miles away, over rough terrain. It comes in fairly close to what the 8200P did, which is to say, it comes in on good days, and looks terrible on bad days. For stations beyond 60 miles, however, the 8200P was a far better antenna. On lo-VHF, the 91XG is terrible, even in the presences of fairly strong signals.

That is exactly the wrong way to visualize how an antenna works. The correct way is to visualize the antenna as a composite with a specific current magnitude and current direction developed on each part of the physical structure. The magnitude and direction vector of these currents creates a wave-front aperture which is realized as the directional pattern of the antenna....

Visualizing that each and every element in a multi-bay antenna receives the same electron stream as each and every other element in an attic installation is a very poor way to contemplate the likely effect of the unique signal streams that hit each element.

Antenna signals received by active antenna elements in attic antennas have been degraded by the reflective, refractive, diffusive and attenuative (whew!) characteristics of the shingles, rafters, joists, flashing, ductwork, and sometimes crates of Christmas decorations and old toys that block and degrade signals on the direct signal path and variously refract otherwise off-target signal streams back toward the reception elements.

I don't get calls from television stations to troubleshoot their off-air antenna reception problems because it is a lot easier for them to evaluate the performance of those antennas, since they are on 500' tall towers. But I did once get a call from one of the nuclear physicists who worked on the first hydrogen bomb to help him with his attic antenna reception because having a Ph D in physics didn't provide him with the means to mathematize the blur of signals pervading his attic.

I got him better reception with a 4 bay bowtie than he was getting with a big Yagi. Yet if the choice of antennas had been made simply based on the HDTV Primer models, then, unless each undesired signal reflection conveniently fell right in the nulls of the bowtie (which would be impossible in the real world, because the null angle decreases with frequency, yet the solid object off which the reflection is bounced stays in one place) he would have chosen the poorer performing Yagi. Welcome to the real world.

The stuff about multiple elements rejecting multipath from the other posters is totally unfounded.

I defer to your greater knowledge of antenna theory. I would appreciate it, however, if you would not only critique other's explanations, but also give your own for the real-world experiences of AltAntMike and many others. If theory says the yagi should be better (and gain-wise/aperature-wise, it *ought* to be) but practice shows that it is not, then there is a problem with the theory.

Theory is only as good as the ASSUMPTIONS.....

If you ASSUME free space without any multipath signal variations, then aperature is all you got to argue with....

GIGO....

Hold on folks. I'm not refuting the consensus that colinear (bowtie) antennas work better in attics. I'm a firm believer in real world observations, and I fully appreciate the extensive experience of an antenna installer like AntAltMike.

However, the explanations set forth as to why the colinear works better than the yagi were not based on sound antenna theory. As someone who knows a little bit about the subject, I'm compelled to post information that's based on real physics.

That's because there exists a balance between empirical methods and scientific methods. A good example of this is the development of long high gain yagis. Before the advent of computer simulation, yagis were designed by empirical methods. That is, cut and try. Attempts to design high gain yagis with that methodology failed miserably due to the sheer complexity. A long yagi for 400 MHz could have 30 elements. That's a lot of cutting and trying. It wasn't until the mid 1980's and the introduction of antenna modeling software (and PC's powerful enough to run that software), that long yagi designs started working satisfactorily. These days, arbitrarily long yagis can be designed limited only by their physical construction.

Getting back to the attic problem, I'd like to suggest that the real issue is detuning of the antenna due to the close proximity of it's surroundings. Yagis are a much higher "Q" antenna a suffer much more detuning than a lower "Q" structure like the colinear. I've noticed this effect on my own 50 MHz yagi which is surrounded by trees (a mixed blessing, since it does hide the beast from many neighbors). The close proximity of the trees lowers the resonant frequency by about 200 kHz and seems to negatively affect it's performance (compared to similar stations with antennas in the clear).

http://img344.imageshack.us/img344/9499/6m7jhv5yi.jpg

Ron

Before the advent of computer simulation, yagis were designed by empirical methods.

Yagis are a much higher "Q" antenna a suffer much more detuning than a lower "Q" structure like the colinear.

I was under the impression that the length and distance of the parasitic elements was established in an equation by Mr. Yagi, but perhaps my information was wrong.

I readily admit to having no idea what "Q" is.

"I have an I.Q. of 160."
- Reggie Jackson

"Out of what, a thousand?"
-Mickey Rivers

holl_ands> Attics have lots of nearby objects that cause even more complex
holl_ands> multipath reflections.
holl_ands> An 8-Bay antenna has many receiving elements distributed in space.
holl_ands> This means that some of the elements may be in signal maxima, while
holl_ands> others are in minima. Big advantage for the 8-Bay.

dieter> So the aperture of the antenna depends on
dieter> the gain, rather than the architecture. For example, the 91XG is
dieter> generally considered to have
dieter> about the same performance as an 8-bay bowtie. Thus it should have
dieter> about the same aperture.

sregener> The problem is multipath, not aperture.

I was responding to holl_ands' theory that the 8-Bay has an advantage
because it has many receiving elements distributed in space.
A Yagi with the same gain will have the same size aperture, and thus
would also have part of its aperture in signal maxima and other parts
in signal minima.

I've been thinking about this issue, and have come to the conclusion
that what counts is the radiation pattern, not the architecture.

Of course, in the real world, the radiation pattern is not identical.
It may be that the side lobes and nulls are a significant difference,
especially indoors.

dieter> The 8-bay bowtie would have an advantage in that if you have a gable
dieter> facing the transmitters, you could place the 8-bay very close to the
dieter> outside wall. This should decrease the reception of reflections
dieter> from within the attic. The Yagi-Uda's dipole must be well back from
dieter> the outside wall, which might admit more reflections? On the other
dieter> hand, if you have a very low pitched roof, the Yagi-Uda might have
dieter> the advantage?

sregener> And there really is no big
sregener> advantage to being closer to the outside wall, as all the losses occur
sregener> in the materials, not in the free space behind it.

I'm not concerned with losses, I'm concerned with multipath.

If one has an attic with lots of ducts, wires, and such, one could think
of the attic as a pinball machine, with the incoming signal as the pinball.
If you place the antenna close to the incoming pinballs, and upgrade the
reflector to solid sheet metal (no worries about wind load indoors), there
should be less chance for a multipath pinball to reach the dipole(s).

I was under the impression that the length and distance of the parasitic elements was established in an equation by Mr. Yagi, but perhaps my information was wrong.

I readily admit to having no idea what "Q" is.
Yagi invented the general structure (driven element, shorter director(s) and longer reflector), but the specific element lengths and spacings are just design variables. The major design parameters are forward gain, front to back ratio and bandwidth. Unfortunately, all three parameters cannot be optimized at the same time, so there are many possible designs.

In the late 1970's, the National Bureau of Standards (NBS) did some modeling (on a mainframe) along with test range measurements, and came up with set of recommended Yagi designs.

http://tf.nist.gov/timefreq/general/pdf/451.pdf

In the 1980's, when antenna modeling software became available for PC's, the first thing folks did was model the NBS designs. They quickly found that the NBS designs were less than optimum. For example, the modeling software showed that the trigonal reflector (Figure 2 in the linked pdf) was a waste of aluminum (increased the windload) and actually decreased the forward gain a few tenths of a dB. Quite a few commercial designs employed the trigonal relector (I had a couple of antennas for 144 MHz that used it), but you won't find it on any current designs (although I think some of the Funke TV antennas still use it).

The "Q" of an antenna is similar to the Q of an LC tuned circuit. It detemines the bandwidth of the antenna. Yagis are typically narrow bandwidth (10% of design frequency), so they are fairly high Q. Of course, TV yagis are tweaked to be wide bandwidth by using directors for the high end of the band coupled to a driven element and corner reflector for the low end of the band (in fact, I don't really think of TV Yagis as "true" Yagis).

A high-Q antenna is more more sensitive to detuning from surrounding objects. The 50 MHz antenna in the picture I posted (designed for high forward gain) is super high-Q, since it's bandwidth is only 400 kHz or less than 1% of the design frequency. It gets detuned from just getting wet from rain.

Ron

A classic Yagi-Uda (i.e. per textbooks or downloadable "Yagi" design software) is actually the optimized,
high gain configuration, with very narrow bandwidth....on the order of a few percent.
In 1954, Uda and Mushiake wrote the "Yagi-Uda Antenna" book, describing optimized designs for 2 and 3 element antenna.

By "detuning" the element lengths and especially spacing, the usable bandwidth can be pushed to maybe 5 to 10 percent:
http://www.cebik.com/yagi/3lyg2.html
There are lots of other examples here:
http://www.cebik.com/radio.html

But that's not even close to what is needed for TV bands....2:1 for UHF.
It helps to use fan dipole radiator elements (like CM-4221 and CM-4228),
which improves the Gain and VSWR throughout the UHF band, at the expense of max gain.
This might also explain why the 91XG is such a good performer compared to other long Yagi's.

Note that the W-G PR-4400 and PR-8800 employ simple dipole radiator elements--and sort of a triangular reflector element arrangement.

====================================================
High gain, narrow bandwidth Yagi-Uda and low gain, wide bandwith LPDA designs are described with fairly simple mathematical equations--
which are readily calculated using available spread sheets.

The advent of computers made possible exhaustive searches of many different element lengths and spacings, "Method of Moments" Integral Equation Analysis,
which evolved into NEC.
From this came the 50-year old designs we still use today, including multi-band quasi-LPDA's, wide bandwidth "Yagi's", the forward swept "fishbone" antenna and those multi-band interlaced monstrosities:
http://www.ece.uiuc.edu/alumni/su04/antennas.html

Lately, "Genetic" search methods are being employed to search for a quasi-optimum arrangement of what look like random wire arrangements:
http://www.jemengineering.com/Genetic%20Antenna%20Design%20Review%203-29-05.pdf
http://ic.arc.nasa.gov/people/jlohn/Papers/ices2001.pdf
Note that the optimized, single band "Yagi-Uda" had elements that did NOT uniformly decrease in length.

FYI: Check out the latest FM Quadrapole transmit antenna at NAB2006 (see jpg).

Note Cibrik's NEC studies for antennas with a reflector and multiple dipoles:
http://www.cebik.com/vhf/f432.html
http://www.cebik.com/vhf/planar.html

In the 1980's, when antenna modeling software became available for PC's, the first thing folks did was model the NBS designs. They quickly found that the NBS designs were less than optimum. For example, the modeling software showed that the trigonal reflector (Figure 2 in the linked pdf) was a waste of aluminum (increased the windload) and actually decreased the forward gain a few tenths of a dB. Quite a few commercial designs employed the trigonal relector (I had a couple of antennas for 144 MHz that used it), but you won't find it on any current designs (although I think some of the Funke TV antennas still use it).

A high-Q antenna is more more sensitive to detuning from surrounding objects. The 50 MHz antenna in the picture I posted (designed for high forward gain) is super high-Q, since it's bandwidth is only 400 kHz or less than 1% of the design frequency. It gets detuned from just getting wet from rain.

Ron
As I recall, the TRIGONAL reflector arrangement was reported to be ineffective for SHORT Yagi's,
where the author reported he could obtain even more gain by extending the Yagi element lengths:
http://www.qsl.net/kd4cga/antenn1.htm
http://lists.contesting.com/archives/html/Towertalk/2001-02/msg00167.html
http://www.rf.org/crms/projects/cushcraftboomer.html
The TRIGONAL was also derided in the context of very large HF/VHF arrays due to the increase in windloading.

That tells me two things about the Yagi design: 1) it probably wasn't optimum to begin with and
2) it probably did not include detuning effects of nearby objects.

Since HF/VHF Arrays are so close to the ground plane, more realistic results would model the ground, house, (trees?) and tower. HF antenna systems can now be modeled to include the effects of not only the ground plane wires, but also the nearby terrain.

The effect of the nearby ground was included in this early (1928) antenna study that treated the TRIGONAL reflector separate from the Yagi-Uda:
http://www.dee.eng.ufba.br/trabalho/yagi/artigo.pdf

Lessons learned from short Yagi's should not be directly applied to long VHF/UHF antennas,
where the TRIGONAL reflector has been reported to be significantly more effective than a single reflector element.
For example in the above cited NBS TN688, after optimization, the long (4.2-lamda) Yagi had 0.75 dB higher gain with the TRIGONAL reflector than with a simple rod reflector element. This was reportedly higher than any of the other tested reflector arrangements (planar, solid, parabola, corner)....unfortunately no details were included.

=====================================
Nonetheless, I still believe a Corner Reflector is effective, although at the expense of even higher wind loading.

Interested parties might want to peruse Cebik's designs for a Super Sized Corner Reflector:
http://www.cebik.com/vhf/corn1.html
http://www.cebik.com/vhf/corner.html
WOW, nearly as much gain as a Yagi with only one dipole driver element....
With less wind load than a parabolic and a LOT easier for a hobbist to build...

Darn, he didn't do a Corner-Yagi....or a Corner-Yagi-Bowtie...
Must have been left as exercises for the student.....

======================================
BTW: The models that Tom Nist assumed for NEC simulations in
http://www.hdtvprimer.com/ANTENNAS/comparing.html
are given here: http://hometown.aol.com/kq6qv/SIMS/
The ants.xls file summarizes the detailed gain parameters on sheet 1 and the gain plots on sheet 2.

The gain of Blonder Tongue cut to channel Yagis really drops off a cliff at the lower edge of the tuned channel, whereas it tapers off more gradually at the upper edge. In other words, if you use a channel 5 BT Yagi for channel 4 reception, or a channel 9 for channel 7, the picture will be unwatchably ugly due largely due to the lack of flatness across the channel, but you can often live with the performance of a channel 4 antenna will give when used for channel 5 or a channel 7 used for 9.

I have to make such, "replace or Kludge" choice several times a year since most customers of mine who still maintain their master antenna systems for the dozen or so residents who are too cheap to buy cable, are not eager to replace cut-to-channel antennas when one fails.

I was planning to buy an Antennacraft Y5-2-6 (http://www.starkelectronic.com/acantena.htm#Y5) antenna and channelmaster 7777 preamp as suggested here (http://www.avsforum.com/avs-vb/showthread.php?p=7564438&&#post7564438), but after reading a little more of this thread I'm not so sure. I only need to pick up a single VHF station (ch. 3) from 35 miles away, and I need an antenna that can be mounted in my attic. Stark Electronics did not have the Y5-2-6, but instead recommended the Winegard YA6260. Would a cut-to-channel antenna have a better chance at pulling in ch. 3 or should I give the Winegard a shot?

I was planning to buy an Antennacraft Y5-2-6 (http://www.starkelectronic.com/acantena.htm#Y5) antenna and channelmaster 7777 preamp as suggested here (http://www.avsforum.com/avs-vb/showthread.php?p=7564438&&#post7564438), but after reading a little more of this thread I'm not so sure. I only need to pick up a single VHF station (ch. 3) from 35 miles away, and I need an antenna that can be mounted in my attic. Stark Electronics did not have the Y5-2-6, but instead recommended the Winegard YA6260. Would a cut-to-channel antenna have a better chance at pulling in ch. 3 or should I give the Winegard a shot?
Have you visited the Chicage thread? They will commiserate with you over there. There are problems with an adjacent analog signal, local impulse noise, and transmitter power in general that make that channel tough to receive. No one can reliably assess whether the minuscule benefit of using a channel 3 antenna over a 2-6 antenna will put you across the performance threshold. Most likely, it won't. You might as well start with rabbit ears or make your own channel 3 dipole in the attic with a couple of pieces of wire about 50 or so inches long and oriented to form a "T" perpendicular to the direction of the transmitter and go from there.

I think that digital 3 might be going to channel 11 when the transition is complete.

Before this forum achieved its present format, there were at least two multipage threads dedicated to WBBM reception. The is also a Lo-VHF thread still allowed since it is such a special case. I have a very large combo antenna only 11 miles from the source. I still use the D* national satellite feed for WBBM because it's more reliable than OTA.

Before this forum achieved its present format, there were at least two multipage threads dedicated to WBBM reception. The is also a Lo-VHF thread still allowed since it is such a special case. I have a very large combo antenna only 11 miles from the source. I still use the D* national satellite feed for WBBM because it's more reliable than OTA.
Thanks. I get standard def WBBM just fine with DirecTV, but now I'm debating whether or not getting it in high-def is worth the hassle. Since I have to mount in my attic, I doubt I'd get any reception at all without an amp. I guess $50 for an antenna and $60 for an amp is pretty cheap to do an experiment. I'm just curious if my chances are decent, or if I don't have a prayer. I'll check out the WBBM threads.

Try it without the preamp first, and if you try a preamp, make sure it contains an FM trap. In most instances, the impediment to successful reception of a VHF lowband signal is impulse noise rather than signal strength.

Thanks. I get standard def WBBM just fine with DirecTV, but now I'm debating whether or not getting it in high-def is worth the hassle. Since I have to mount in my attic, I doubt I'd get any reception at all without an amp. I guess $50 for an antenna and $60 for an amp is pretty cheap to do an experiment. I'm just curious if my chances are decent, or if I don't have a prayer. I'll check out the WBBM threads. You need to check out the local Chicago OTA thread. I don't presently get WBBM OTA, but I can usually get CBS from Rockford. Believe me - it looks a HECK of a lot better, even on a 480i TV, then satellite's SD WBBM signal. The satellite locals are terrible. Letterman may not be as good as he once was, but you may even start watching him again after you see how great the show looks.

I have a HDTV receiver (SAMSUNG 150) and a 46" TV and am using DIRECTV. A waiver for me was denied by my local affiliates for me to pick up the HD channels for CBS, NDC, FOX, and ABC. I live 40 miles from Jax fla. So I purchased a Radio Shack Model: VU-120 XR , 120 inch BOOM and also have a PREAMP installed on it. I look at my signal strength and they run 80 - 90 %, except NBC is around 70 %. Antennaweb shows the stations at 172 and 173 degrees from my location. While attempting to watch a program using the OTA antenna, the signal will drop and it will take around 10-20 seconds each time. (My DTV signal does not do this) This happens about every 8 - 10 minutes and its VERY annoying. It even does it when the weather is perfect. The antenna is 20 ft high, but about 25 yards beyond it is a patch of pine trees and oak trees. I have tried adjusting the antenna, and even moved it to different locations around the yard. Do I need a different antenna, different type of amp, or move? Any suggestions are appreciated.

> So I purchased a Radio Shack

Radio Shack products tend to not be the highest quality.
I'm not suggesting that you necessarily need to upgrade,
but keep it in mind for the future.

> It even does it when the weather is perfect. The antenna
> is 20 ft high, but about 25 yards beyond it is a patch
> of pine trees and oak trees.

Are the trees blowing in the wind when you get the dropouts?

Getting the antenna above the trees should help, but that might
take quite the tower.

Experts:

Do some antennas do better with trees than others?

Do some demodulators do better than others against trees?

Is the theory still that blowing trees modulate the
signal amplitude, as opposed to generating multipath?
I've been reading about the 5th generation demodulators,
and thus far it is all about multipath, nothing about
a better AGC or whatever it takes to work with trees.

Hey gang,

OK, let's say you wat to watch DTV stations from 40 miles away in your Dodge Caravan. You can get an RG-6 cable, no problem, to the roof. There is a roof mount for antennas. You will have a DTV tuner in a laptop, a Winegard 29/28db gain VHF/UHF preamp, and...an antenna.

What antenna should someone use in a situation like this that also drives in thunderstorm activity frequently?

Receving DTV stations on the road...interesting concept, no? Assume 4th generation tuner card. Any news on the 5th generations (besides DirecTV)?

...You will have a DTV tuner in a laptop, a Winegard 29/28db gain VHF/UHF preamp, and...an antenna.
Why the h*ll would you want to use a preamp with that much gain?
....jc

Why the h*ll would you want to use a preamp with that much gain?
....jc

Forgot to mention...will be in use in areas well away (60 miles) from transmitters while in motion.

Forgot to mention...will be in use in areas well away (60 miles) from transmitters while in motion.
So? You are implying that a preamp is some sort of a magic device. It isn't. If it were, we could put up a matchbox sized antenna, and let the preamp do all the work.

That said, I'd try some sort of an omni-directional antenna(otherwise how do ya aim it?), w/o a preamp, and see how it works.
....jc

While attempting to watch a program using the OTA antenna, the signal will drop and it will take around 10-20 seconds each time. Do I need a different antenna, different type of amp, or move? Any suggestions are appreciated.

I'd try moving the antenna higher onto a mast, tripod, or small tower. Antennaweb doesn't show any NBC reception at your location, so that's an indication that your antenna was properly installed.

So? You are implying that a preamp is some sort of a magic device. It isn't. If it were, we could put up a matchbox sized antenna, and let the preamp do all the work.

That said, I'd try some sort of an omni-directional antenna(otherwise how do ya aim it?), w/o a preamp, and see how it works.
....jc
To get digital reception mobile at 40-60 miles might take some kind of miracle. DTV reception requires a semblance of steady data flow which is easily interrupted by changing surroundings. I say it probably can't be done, especially in an urban setting.

So? You are implying that a preamp is some sort of a magic device. It isn't. If it were, we could put up a matchbox sized antenna, and let the preamp do all the work.

That said, I'd try some sort of an omni-directional antenna(otherwise how do ya aim it?), w/o a preamp, and see how it works.
....jc

Didn't mean to imply that. Rather, the signals from an omnidirectional antenna
are probably weak, and would need to be amplified for a more consistent signal (albeit maybe not with anywhere near that amplification, depending on the antenna).

Any recommendations for an omnidirectional?

Hey gang,

OK, let's say you wat to watch DTV stations from 40 miles away in your Dodge Caravan. You can get an RG-6 cable, no problem, to the roof. There is a roof mount for antennas. You will have a DTV tuner in a laptop, a Winegard 29/28db gain VHF/UHF preamp, and...an antenna.

What antenna should someone use in a situation like this that also drives in thunderstorm activity frequently?

Receving DTV stations on the road...interesting concept, no? Assume 4th generation tuner card. Any news on the 5th generations (besides DirecTV)?
Good luck with your science experiment---be sure to let us know how it works.
If you're parked, you gotta shot---however, watching DTV while moving will be quite a challenge.

At 40+ miles, even if you're parked, you'll need a moderate gain antenna pointed towards the desired station....forget the omni...
And the higher the better.....the closer you mount the antenna to the vehicle, the more it's gonna reduce the signal.
There are antennas intended for mobile use that have more gain and multipath rejection than an omni or simple dipole.....
but you won't find it at Winegard.

At home, I'm currently using the DX Antenna DTA-5000 Smart Antenna (with variable gain Preamps) with the Sylvania 6900DTE OTA STB, which is (thus far) the one and only STB with the EIA/CEA-909 Smart Antenna Control Interface:
http://www.avsforum.com/avs-vb/showthread.php?p=5979741&#post5979741
http://www.avsforum.com/avs-vb/showthread.php?p=5891449&#post5891449
http://www.avsforum.com/avs-vb/showthread.php?p=5826625&#post5826625
Unfortunately, the DTA-5000 doesn't automatically track signal direction changes, requiring 15-20 minutes each time you request it to readapt the antenna settings.
If you don't want to go the Smart Antenna route, the last post provides links to the DX Antenna DTA-3500 and DTA-3000, which are manually steered.

==================================================
If you are moving, there is (at least) a double whammy working against you: doppler and dynamic multipath.
These aspects are discussed at length in the references I listed in the fol. posts:
http://www.avsforum.com/avs-vb/showthread.php?p=6211062&#post6211062
http://www.avsforum.com/avs-vb/showthread.php?p=5842783&#post5842783
Current ATSC Receivers are not designed to track doppler offsets, nor are any yet available with the dual (or preferable triple or quad) antenna diversity needed to work around those nasty dynamic multipath nulls.

The above references summarize the performance of single vs dual antenna diversity systems employing European COFDM DVB-T Receivers. Antenna Diversity provided the dramatic improvement in performance that was needed to overcome dynamic multipath nulls--but there were still doppler correction limitations that limited the top speed to sub-Autobahn speeds.

The current ATSC waveform is much more susceptible to multipath, dynamic multipath and doppler.
So it's gonna need a lot more help to work in a mobile environment.
Which is why ATSC approved the robust Enhanced VSB (E-8VSB) in 2004 and is currently considering the even more robust Advanced VSB (A-VSB) proposal, both of which use error detection coding and other techniques to improve performance and H.264 (MPEG4/AVC) or VC-1 to overcome the subsequent loss in data rate:
http://www.avsforum.com/avs-vb/showthread.php?p=7647247&#post7647247

And other mobile TV competitors are implementing variations of COFDM, like MEDIAFLO and DVB-H.....coming soon to your mobile van...

================================================
You might want to consider a SAT system with "In-Motion" antenna:
http://www.winegard.com/mobile/movinview.htm
http://www.winegard.com/mobile/roadtrip.htm

================================================
PS: Analog NTSC Receivers are readily available for mobile use---nearly all of which use dual (or quad) antenna diversity....

Good luck with your science experiment---be sure to let us know how it works.
If you're parked, you gotta shot---however, watching DTV while moving will be quite a challenge.

At 40+ miles, even if you're parked, you'll need a moderate gain antenna pointed towards the desired station....forget the omni...
And the higher the better.....the closer you mount the antenna to the vehicle, the more it's gonna reduce the signal.


LOL! Science experiment, yes. Between doppler shift, signal reflections off the van, etc...it's daunting.

Right now the van owners have a "windshield" TV antenna on the inside. Looks like those old windshield AM/FM antennas, but on a "patch" that looks odd. Never had to deal with reception in vehicles before, so this is new to me. However, physics is physics, and non-directional=low gain/negative gain, no matter what.
This "antenna" looks cheesy and I have tried the reception capabilities...once.
Was completely underwhelmed with it. :rolleyes:

Yeah, I know they'll have to be parked. But they travel in rural areas in relatively flat terrain. That will help. Question: will the DTA-5000 improve reception
with ANY tuner, not just the Sylvania one? Or is it model-specific to see the improvements you did?


It probably won't be soon before I try to tackle this with them, but I am trying to get a head start for them. Thanks for your insight, as always!

Should I replace my current RG-59 cable with the new RG-6 cable? I have two 12 feet RG-59 cables from a CM 4228 and a CM 4221 combine with a two splitter in reverse into a 50 feet of RG-59 cable to my HDTV. It will cost my about $30 to upgrade. Will it worth the cost to upgrade? Any opinions will be accepted. Thanks in advance...

Do you have a problem right now? RG6 will have lower loss but, unless something is wrong, why bother?

LOL! Science experiment, yes. Between doppler shift, signal reflections off the van, etc...it's daunting.

Right now the van owners have a "windshield" TV antenna on the inside. Looks like those old windshield AM/FM antennas, but on a "patch" that looks odd. Never had to deal with reception in vehicles before, so this is new to me. However, physics is physics, and non-directional=low gain/negative gain, no matter what.
This "antenna" looks cheesy and I have tried the reception capabilities...once.
Was completely underwhelmed with it. :rolleyes:

Yeah, I know they'll have to be parked. But they travel in rural areas in relatively flat terrain. That will help. Question: will the DTA-5000 improve reception
with ANY tuner, not just the Sylvania one? Or is it model-specific to see the improvements you did?


It probably won't be soon before I try to tackle this with them, but I am trying to get a head start for them. Thanks for your insight, as always!
DTA-5000 only responds to EIA/CEA-909 Smart Antenna Interface controls and hence is only compatible with Sylvania/Funai 6900DTE.
It uses crossed dipoles for VHF and a N/S/E/W array of two-element Yagi antennas (reflector and driven element) for UHF.
I found it to be about as effective as a 4-Bay antenna in both indoor and outdoor comparison tests.
The DTA-3500 appears to have specs that are very close and will accept manual controls.

If you want a more effective antenna, you might want to consider "erecting" the CM-4228 from a stowed position (which might have something to block the full force of the wind when moving).

If you've got money to burn, Katherein-Scala makes the somewhat lower gain CL-1469B LPDA, which has a fiberglass housing:
http://www.kathrein-scala.com/catalog/CL-1469B.pdf
This was the "standard" antenna in on-the-air comparison tests reported by Bob Chase:
http://www.avsforum.com/avs-vb/showthread.php?p=5399471&#post5399471

Between doppler shift, signal reflections off the van, etc...it's daunting.

There should be no doppler shift. You're comparing the speed of light to 60mph. That's why it doesn't matter which direction you're headed - radio sounds the same.

Is the Winegard CS-7750 VHF/UHF separator/coupler shielded?
I haven't found a description that tells whether the case is
metal or plastic.

Same shielding question for the Winegard CA-8800 FM BAND separator/coupler.
Does the CA-8800 pass both low and high VHF and not hurt channel 6?
Would the CA-8800 work as a FM trap? (Attach a terminator to the
FM output.)

The FT-7500 TRAP is described as having a plastic housing, thus
I assume it is not shielded. Also it is described as hurting
channel 6. I'm surprised that I haven't found a version that
passes chan 6.

Same questions for FT-7600 Variable FM Trap (75 ohm)
Shielded? Can it be adjusted to not hurt chan 6?

Does Winegard make a separator/coupler to split low-VHF from
high-VHF? I haven't found one.

I assume the Channel Master versions are all unshielded plastic?

Are there other brands I should consider?

Even moderate speeds create significant doppler offsets in the VHF/UHF bands.
The higher the frequency, the larger the doppler shift in received carrier frequency:
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/reldop3.html
and for velocity much less than the speed of light:
http://www.viestikallio.fi/tools/doppler.php
This yields a calculated doppler of as much as 84 Hz at 70 mph for (worst case) CH69.

The fol. post gives you some idea of the amount of doppler observed by a home-brew doppler radar system operating at 26 MHz:
http://www.qsl.net/g3cwi/doppler.htm
If you scale the frequency of operation for the UHF band, the doppler shifts will be about 20 times larger.

==================================================
DTV Doppler "flutter" effects due to reflections off of moving aircraft of as much as 150 Hz are calculated and discussed in sec 4.5.3.4 of ATSC A/74, "ATSC Recommended Practices, Receiver Performance Guidelines":
http://www.atsc.org/standards/practices/a74.html

The CRC (Canadian Research Center) conducted tests on several prototype ATSC Receivers:
http://www.crc.ca/en/html/crc/home/research/broadcast/rtnt

In the most recent (and hence best performing) PROTOTYPE Samsung STB, only fairly small doppler offsets could be tolerated under typical multipath test conditions. Moderate amounts of doppler could be tolerated, but only when the multipath components were at much lower levels than the primary signal.

In earlier tests of the PROTOTYPE 5th Gen Zenith/LG STB, the doppler tolerance was even more limited, as was the ability to tolerate "0 dB" multipath wherein the multipath signal strength is nearly the same as the primary signal.

========================================
BTW: Doppler Correction is also necessary for data comm systems operating with not only aircraft in the HF band, but also to partially compensate for the doppler shifts due to extreme turbulence in the ionosphere.

And of course, doppler offsets for non-synchronous SATCOM systems (like GPS) are significantly higher....

"If you are in a spaceship that is traveling at the speed of light, and you turn on the headlights, does anything happen?"


- Steven Wright

Hello everyone,

I recently got a Dell XPS 400 with XP MCE and dual NTSC tuner, so I decided to add an ATSC tuner since ABC, Fox, and PBS broadcast in digital here. I got the Dvico FusionHDTV5 RT lite ATSC tuner card, and a cheap $12 Wal-Mart RCA ANT145 VHF/UHF antenna.

Adjusting the UHF loop and turning the knob, I was able to get 93-97% signal on ABC, 72-80% on Fox, and 75-85% on PBS, all at different UHF antenna angles and knob settings (the broadcast frequencies are all in the UHF range). So I thought if this cheapo antenna is this good, the Silver Sensor should be loads better, right?

Wrong!

I hooked up the Silver Sensor and turn and twisted it, and I could barely get ABC! The other 2 were out of the question.

How could this be? I thought the Silver Sensor was "the" indoor antenna to get. I do live in a south facing apartment and the towers are north of me, so my only explanation was I was getting some useful omnidirectional reception from reflected signal and the Silver Sensor was too directional possibly.

Any ideas? I'm about to send the Silver Sensor back.

Brian

I haven't used the others, but can address Konrad's CA-8800 questions to some extent, and explain how I'm using a CA-8800, just in case it's of any use.


Same shielding question for the Winegard CA-8800 FM BAND separator/coupler.


The "case" on CA-8800 I purchased January 2005 is "metal", appears to be aluminum, or a similar alloy. I purchased it from a local distributor who didn't have one in stock, they had to order it from Winegard. Took a week or two as I recall.


Does the CA-8800 pass both low and high VHF and not hurt channel 6?


It passes ch 2-6 and 7-13 as well as(per the specs on winegard site) UHF ch 14-69 on the TV port. I haven't personally checked for insertion loss on UHF, as I only use it with VHF+FM(more on this below). I can't say with 100% certianity that "ch 6 is not effected", however I have no problems receiving weak analog stations on channel 6 with TV hooked to "TV" port, nor do I have problems with weak audio carriers from those same channel 6 stations on FM receiver tuned to 87.7MHZ and hooked to its FM port.

Note : As the description on winegard site would seem to imply -- I believe the "TV" and "FM" ports could be used either as a "band seperator" (as I'm using it, even though the ports are labeled "TV", FM" and "Input"), or a "coupler" - such as with seperate TV and FM antennas hooked to the "TV" and "FM" ports respectively.


Would the CA-8800 work as a FM trap? (Attach a terminator to the
FM output.)


I don't think so, at least I suspect nowhere near as well as a "real" FM trap. I suspect even Radio shack's FM trap would be much better. Although I haven't tried a terminator on one side to see what happens, nor have I spent much time "fiddling with it" to see ...

From what I can tell from a brief check with it I performed, using the FM+TV ports as "output ports" -- FM signals seem to be "significantly" passed via the "TV" port, and TV signals(at least on VHF) seem to be "significantly" passed via the "FM" port. For instance, just for the heck of it, I hooked up a TV to the "FM" side and still picked up quite strong local VHF signals with it(hi-VHF may not have been quite as "pretty" however), even enough so that a weak signal on 3 from a station 95 miles away was present. And, I certianly still need a FM trap in line on the TV side.

I believe it does have less insertion loss than a 2 way splitter, and for my application that's mainly why I ordered it. My experience with it does lead me to wonder how much isolation there actually is between the "TV" and "FM" port if you are using it as a coupler for seperate TV+FM antennas ...

For the antenna setup, I use it with --- I use seperate feedlines(coax) from seperate VHF+UHF antennas(used with rotor in some cases) to the attic. For VHF/FM, the feedline from a broadband ch 2-13 VHF+FM antenna(Winegard PR5030 - which btw seems to have an "odd" pattern on FM above about 93 MHZ or so, 88~92 MHZ makes perfect sense per the polar patterns for ~ch 6 shown in Winegard's spec sheet) goes into attic, then to CA-8800 - I have feed from the "FM" port on CA-8800 feeding A FM receiver, so I can get FM signals off the antenna before using FM traps and VHF TV channel traps(notch filters) after the TV port.

On the TV side, after the "TV port" from the CA-8800, I have several channel traps from Blonder-Tongue+Winegard in line to knock down strong analog stations on 2+7. note : I use a different antenna setup, on different feedline+A/B switch(s) before receiver(s) to receive those stations as well as UHF digital stations from that market.

I have one of the Winegard traps (a TRT-LO, tunable from 54~88MHZ - I don't think they make the VHF "TRT" traps any more) tuned for greatest "notch" on 88.7MHZ. The specs say it does a -12db notch, half power points at 2MHZ bandwidth. I do this because I have several strong low-FM signals, and the FM traps I've used/tried(note the FM trap in CM7778 seems to work as well as any I've tried) don't quite knock down strong low-FM signals (especailly stations on 88~89 MHZ in my area) enough so channel 6 reception isn't effected, including with the CA-8800 in line.

For instance, without the TRT-LO tuned to knock down low-FM, I'd guess(just guessing really) probably mostly due to "selectivity" issues involving consumer NTSC tuners in TV's --- one particuarly strong station on 88.1MHZ 12 miles distant(NE) pretty much "wipes out"(or makes it look very "ugly") a analog TV station on channel 6(78 miles away - ENE) in nearly the same direction.

While the TRT-LO tuned for 88.7 does seem to slightly effect a weak Channel 6 audio carrier (87.75 MHZ), I can(and do occasionally) tune the FM receiver to 87.7 for the ch 6 audio when necessary, as the "effect" from the strong FM's in several directions on 88.1~88.5, especially w/o the TRT-Lo tuned for 88.7 is even worse anyway ....

Another particularly difficult situation this works well with is a strong FM on 88.5 in nearly the same direction(WSW - 18 miles) as another occasionally viewed analog station on channel 6 approx 100 miles(west) distant.

Anyhow, after the channel traps, the VHF TV feed goes to a CM7778 preamp(with FM trap engaged) and its power supply, then to VHF port on CM0549 VHF/UHF joiner. An XG91 with winegard Mast mount AC-4990 preamp is used for UHF, I also have a Winegard UT-27 tunable UHF trap(older version of UT-2700) in line in attic after power supply for preamp to knock down a strong analog on 22 a bit for the "tuners" ....

Probably more than you wanted to know, but just in case some of it helps ....

Why does Konrad2 care about an FM trap? Does he believe his preamp is being overloaded by a local FM station? He won't be able to tune one without a signal meter.

The FT-7500 is the 300 ohm version of the FT-7600 dual notch trap. The notch dimensions are similar to those cited by Nitewatchman in his description of the Winegard traps. The plastic cases are unshielded, but at FM frequencies, the exposed components are inefficient antennas and the ingress is generally of no practical consequence.

Older FT-7500s and 7600s use a .100 inductor adjustment tool, but the newer ones use a .070 tool, which is a little harder to find. One sucky thing about all of them is the tunable inductors are really cheap and once they have been tuned a few times, they tend to stick and become impossible to further retune.

If you need to just knock down a lot of FM stations, cheap FM band-reduction filters commonly used the part numbers FMT and FMT88. An FMT usually supresses the FM band from about 93Mz to 108Mz, whereas the FMT88 attenuates the whole band but severely damages channel 6 analog. As a rule, cities with channel 6 analog stations are smaller cities that do not have strong FM stations at the low end, but there are a few exceptions to that rule, and of course, quite often someone is trying to bring a distant channel 6 into their local market that has a low frequency FM station and therefore may need a notch filter.

Blonder Tongue Hi-Lo separators are engineered to pass the entire FM band, but they probably cost around $20. I think most of the $1 Hi-Los I buy from Holland, Pico, Tru Spec or whomever pass the whole FM band, but I haven't actually tested them.

Tru Spec used to make two models of cheap 75 ohm TV/FM separators that looked like splitters. One was for markets with a channel 6 that rolled off the FM at 93Mz and the other was for markets without one, that passed the entire FM band but would beat up a channel 6 if there was one present. They sold for a couple of bucks each, but there was no demand for them. Unless you are really signal starved, a splitter or tap for the development of an FM port will work just fine.

"If you are in a spaceship that is traveling at the speed of light, and you turn on the headlights, does anything happen?"


- Steven Wright
No, because electrons take forever to travel along the wire in the direction of the headlights.

Not only that, but the taillights also take forever to turn on, due to the need for the electrons to travel back via the ground return path.

===========================================
"OK, so what's the speed of dark?"
- Steven Wright

Should I replace my current RG-59 cable with the new RG-6 cable? I have two 12 feet RG-59 cables from a CM 4228 and a CM 4221 combine with a two splitter in reverse into a 50 feet of RG-59 cable to my HDTV. It will cost my about $30 to upgrade. Will it worth the cost to upgrade? Any opinions will be accepted. Thanks in advance...
Plugging in 803 MHz (for worst case CH69) and 62 ft length, the diff is only about 1 dB:
http://www.timesmicrowave.com/cgi-bin/calculate.pl
So it's hardly worth the effort. Of course, YMMY if you have moisture in the cable....

No, because electrons take forever to travel along the wire in the direction of the headlights.

Not only that, but the taillights also take forever to turn on, due to the need for the electrons to travel back via the ground return path.

===========================================
"OK, so what's the speed of dark?"
- Steven Wright

Well, if the spaceship is traveling at the speed of light, its length will be zero, its mass will be infinite and it will suck the entire universe into a singularity. I wouldn't be concerned about the lights.

I got the Dvico FusionHDTV5 RT lite ATSC tuner card...

How could this be? I thought the Silver Sensor was "the" indoor antenna to get. I do live in a south facing apartment and the towers are north of me, so my only explanation was I was getting some useful omnidirectional reception from reflected signal and the Silver Sensor was too directional possibly.

Starting with the modern tuners like the one in the HDTV5, multipath (called "ghosts" on analog stations) can be beneficial rather than harmful to reception. With those, a less directional antenna may be better than a more directional one.

The Silver Sensor is what it is. In certain circumstances, a bad antenna will outperform a good one. Sounds like that's the case for you. Return the SS and be happy with your RCA.

Starting with the modern tuners like the one in the HDTV5, multipath (called "ghosts" on analog stations) can be beneficial rather than harmful to reception.

Are there any set-top boxes that offer a version of this "modern tuner?" Multipath is a killer in my particular location, and I'd jump at the chance to turn it in my favor.

Are there any set-top boxes that offer a version of this "modern tuner?" Multipath is a killer in my particular location, and I'd jump at the chance to turn it in my favor.
There are "5th Gen" tuners in various PCI Cards, USB Boxes, HDTV's and probably some of the new MPEG4 SAT Rcvrs,
but thus far we don't know of any "5th Gen" or equivalent tuners in either OTA STBs or OTA DVRs.....

Maybe by this summer....
Keep checking the 5TH GEN RCVR CHIP thread:
http://www.avsforum.com/avs-vb/showthread.php?p=7647330#post7647330

Thank you very much.

Hello All,
I have a DB4 antenna hooked to a rotor and mounted on the roof of my house. Recently because of some hail damage I had to get up on the roof and do some repairs. During the process I also did some testing and am curious if this makes sense to anyone. Because of the length of the cable installed I used a Channel Master 7777 PreAmp, when I did my repairs yesterday, when all was said and done, I no longer have the mast mounted part of the 7777 attached, I do however have the 0474 power adapter part hooked up inside. I am getting a pretty good signal on the one VHF channel that historically is the problem, 80-85% signal strength according to the testing on my HD Tivo HR10-250. My question is "does that make any sense" to anyone. If I unplug the 0474 part then the signal goes way down, I am just wondering if I should take the time and effort to reinstall the mast mount part or just leave it. Currently the weather is nice and really things should be coming in well, would hate for alittle weather that would normally not be an issue to become one since I dont have the mast part of the 7777 installed. Thanks for your time.

Rodney