Question about my antenna setup?

[Brigadeer]

I just recently got the greatness of HDTV in all of its glory installed in my home. I am hooked up through DirecTV and OTA using the new Samsung T151 receiver.

I had my antenna mounted in the rafters of my attic, and I get anywhere from 69-77% reception on all of the major networks.

For some reason, NBC seems to come in just fine during the day, but every other nights it seems, NBC will fluctuate from 77% back down to 0 when using my receiver to read the signal strength, and then right back up again. As you can imagine, it makes NBC unwatchable as it breaks in and out every few seconds. Again, this only happens every now and then. The rest of the time it is fine, and none of my other OTA locals do this.

First off, does anyone know why this might be happening? Do you think the issue is with my local NBC signal and carrier? All of my locals broadcast from the same exact point, so there is not an issue of my antenna having to catch signals from different degree angles. They are all coming from the same spot, and only NBC cuts in and out on me.

Second, would installing an amplifier help the situation at all do you think? I have RG6 coax running from my antenna in the attic rafters to the wall behind my TV. I plan on hooking up the amplifier at the end of the line by the TV, as opposed to in the attic. I know that is not as good as hooking it up in the attic, but that is all I feel I would be able to do.

All that said, do you feel that installing an amplifier would help this situation? I would like to get a few opinions on this before I go out and spend $20-$30 at Radio Shack on one.

Thanks for everyones help!

Brigadeer

[pradike]

Unless you're within 15 miles of a tower...

An amplifier can only help your reception.

You can probably expect a 15-50% gain, depending on your equipment.

What kind of antenna are you using? I've found different kinds can drastically change the reception as well (My first one was horrible, my current one a ChannelMaster Stealth is great).

[kevinw]

You have multiple possible problems.
What antenna are you using?
Is the attic roof/ductwork/nails interfering with the signal?
When the picture breaks up does the strength of the signal change?
How far from the towers are you?
If you need an amp mount it as close to the antenna as possible.

[Brigadeer]

Kevin, here are the answers to your questions:

"What antenna are you using?"
I am using a Winegard Platinum HD7210P Ghostkiller

"Is the attic roof/ductwork/nails interfering with the signal?"
I have no idea as I paid someone to install my antenna and to run the RG6 coax down to the outlet by my TV.

"When the picture breaks up does the strength of the signal change?"
Absolutely. When this happens, I use the signal strength meter on my Samsung T-151. The signal rapidly will rise and fall, anywhere from all the way to zero, back up to 30%, and sometimes even 70%. Remember, this ONLY happens to my NBC local. All of my other locals are either at 69 or 77% signal strength every time that I check them. That said, when this occurrs (only every now and then??) it always drops to zero at some point, causing the picture to come in, and then go out.

"How far from the towers are you?"
I believe I am approximately 40 miles from the towers. According to antennaweb and the local HD junkies, all of the HD towers are located about 40 miles South of me, all at the same location, 193 degrees I believe, according to antennaweb.org.

"If you need an amp mount it as close to the antenna as possible"
Although I realize that mounting the amp next to the antenna would be best, I really don't see me being able to do this. When you think of me, think of Tim Allen, an accident waiting to happen. That said, I feel pretty good about installing an amp at the coax output at my wall behind the TV set.

Now that I have answered all of your questions, please give me your best advice. Kevin, I very much appreciate you, as I see you giving competent advice to newbies such as myself all of the time.

I think I speak for all of the newbies everywhere when I say thank you.

Brigadeer

[kevinw]

My guess is 2 possible scenarios, the first is multipath. Multiple signals from the same source, reflections interfering with the STB's ability to lock on the signal. Since your antenna is inside it is more than likely trees -pine tree's ?
An amp could help but it does need to be mounted as close to antenna. The one you would use at the tv is not the same.
The 2nd could be station problems. Here in Atlanta ABC has the identical problems you describe. Not knowing where you reside I would check with local HD clubs(who would think that this could spawn a club) and talk to the station engineer. Amazingly they do appreciate feedback.

[Brigadeer]

Thanks Kevin. Well, this evening, my NBC is now completely out, and my ABC signal strenth is down in the 30's and 40's. It is not going out on me, but is low enough to scare me.

I have decided to go ahead and try to place an amplifier in my attic next to the antenna. I do however have a few questions.

I know that the amplifier will need to be plugged in. Might you be able to give me a rough idea on how to mount and install an amplifier in my attic? The installer placed my antenna in the rafters using some rope to hang it, and I do not believe that there are any power outlets nearby. Thanks!

Brigadeer

[kevinw]

Amps are 2 piece on mounted at th e antenna and one bore thetv/stb
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F003%5F001%5F003%5F001&product%5Fid=15%2D1109
This is the one I use.

[Brigadeer]

Kevin, I bought the Radio shack model you sent to me through the link, and I will be hooking it up this weekend. I will be sure to let you know how it works.

I did however want to ask you another question.

I asked this same question regarding my reception problem on NBC on another forum similar to this one. I got a response back on that forum telling me that my problem was not signal strength so much as it was reflection, and that only moving the antenna would help.

This would seem to make some sense as I check the signal strength on my local NBC station using my Samsung receiver, and it goes from 0 to 77%, going in and out. That said, when the antenna does catch the signal, it tends to be pretty high. I guess the catch is, getting the antenna to consistently grab the signal.

Regardless, I am putting the amplifier in as I am 40+ miles from the towers, and it certainly could not hurt. If you could, would you let me know what you think about the "reflection" issue, and what exactly that is?

Brigadeer

[kevinw]

I my earlier post I suggested multipath and still do. With an amp you can move the antenna off a direct line and still get a signal.
This new amp should help. If you have problems after install make sure to turn the gain down. It is a small insert screw on the module that is closest to your TV. The amp will more than likely increase your strong signals to an overlaod point. When that happens your STB can not lock on a signal. I would think after the amp you will have 90-100 on your signal strength.
If you have any problems PM me this weekend. I'll be checking regularly and can walk you through it if needed. Or Pm with a phone# and I'll give you a call. I'll be home all Sat. morning waiting on DISH to install a 2nd sat. for me.
Good Luck
K

[Brigadeer]

Thanks Kevin. I will definitely take you up on that offer and send you a PM this weekend if I need you.

Again, thanks so very much for your time and advice. I'm glad that you don't charge by the post.

Brigadeer

[Brigadeer]

Well, the amplifier did not help my situation all that much. The only signal that was boosted was my local fox, which went from 78-100%, but then again, who cares when you are talking about Fox. All other locals maybe boosted 5% at best, and that was with it completely turned up.


What did it for me was adjusting the antenna. Apparrently, when the installer put up my antenna in the attic, he had it turned about 30 degrees in the wrong direction. I messed with it for about 30 minutes, and was able to get stable 77% or better signal strength all weekend long. Now, I just need to get those guys back out to remount the antenna.

Brigadeer