Pre Amp Issue/Suggestions

[Bobbj]

Hello,

I am trying to help my brother set up a new antenna at his house which is about 5 miles away from me. I do understand that just moving down the street can cause a difference in signals etc. Both of our tvfool reports are not very good. However I am only trying to get the ABC, CBS, and Fox stations that are nearest to the both of us in the Altoona direction.

At my location which has far worse results http://www.tvfool.com/?option=com_wr...9038db6c160fa2
I can easily get WTAJ, WATM, WWCP, WJAC (even Pittsburgh stations). At my location I tried a CM 7777 amp that would overload and got me 0 channels, CM 7778 which did nothing, and the CM 7777HD adjustable gain extremely improved my results. I normally get 14 channels with it on its lowest setting (some of them co-channels).

There are 2 large cell towers from my location that are in my line of sight that I can physically see towards the Altoona stations. Could I be getting a reflection from the cell towers??

When using the same CM 7777 HD and antennas at my bothers house http://www.tvfool.com/?option=com_wr...9038e93212350b
I get 0 channels even on its lowest setting. When I take the amp off I can normally get 4-8 channels which are WJAC and WTAJ which has me confused.

Anyone have any amp recommendations or reasons I could be getting 0 channels with the amp connected ? Thanks in advance

 

[harshness]

What kind of antennas are we talking about and how are they brought together?

 

[Wireless Engineer]

I never recommend the 7777 or any preamp with more than 20 db gain since they are very easily overloaded by nearby tv and FM stations, LTE, or police, fire, paging, and ham transmiitters.
The Winegard has the best immunity from overload but lacks a LTE filter so you would need to add a channel master filter if LTE is a concern.
The 7778HD is the best offering from Channel Master and would likely be the better choice.
You must enter your exact address into tv fool or it will give bad results.
Merely entering a zip code will not work.
You likey need a channel 2-36 fringe antenna which would be something like the Channel Master Advantage 60 or Advantage 100.

 

[comfortably_numb]

I have the CM-7777HD and it works wonderfully at my location.

 

[Bobbj]

I tried my exact setup (91XG with a 50ft rg6 Coax run into a fire recast) and also a Clearstream 2V antenna. Oddly the 91xg picks up 0 channels from his house vs the smaller Clearstream 2. I’ve contemplated trying a channel master 4228 hd as a majority of the channels are UHF.

At my house which has much weaker signals the Adjustable 7777 HD works perfectly on the low gain setting. I think it also has a built in LTE filter? But when at my brothers location it brings in 0 channels almost as if it is overloading but the signals there are not strong. As mentioned above when I take it off I can typically get 4-8 channels (some not watchable). His tvfool results are not great but they are better than mine. The results listed above were from direct coordinates on the tvfool map at his location. He is also closer to the towers than I am.

 

[pamajestic]

Something seems odd with both of the TVfool reports. Both reports are horrible and show virtually no signal at either location. There is no way any preamp would overload on either report.

Also the report for your brother shows the antenna at 40 feet above ground level. Is that correct?

Try re-running the TVfool report using their map option and move the pin to the exact location of the antenna and enter the correct height above ground level.

 

[Bobbj]

Something seems odd with both of the TVfool reports. Both reports are horrible and show virtually no signal at either location. There is no way any preamp would overload on either report.

Also the report for your brother shows the antenna at 40 feet above ground level. Is that correct?

Try re-running the TVfool report using their map option and move the pin to the exact location of the antenna and enter the correct height above ground level.

The antenna when mounted on the pitch of the roof is easily 35- 40 feet from the ground so that is accurate. Using the tvfool map I had the pin set to the exact location. The roof is metal if that makes a difference? but it is mounted outside. The amp is working fine at my location as I’m using it on my setup right now so that’s what has me baffled.

Is there any other amps I should consider trying at his location? I wasn’t sure if the winegard boost would be strong enough or even a kitztech 200?

 

[pamajestic]

Is there any other amps I should consider trying at his location? I wasn’t sure if the winegard boost would be strong enough or even a kitztech 200?

I don’t think any amp will help. You can not amplify what is not there.

 

[Bobbj]

Agreed that you cannot amplify a non existing signal however when I take the amplifier off at his location I can receive channels which is odd...

 

[harshness]

I never recommend the 7777 or any preamp with more than 20 db gain since they are very easily overloaded by nearby tv and FM stations, LTE, or police, fire, paging, and ham transmiitters

Looking at the TV Fool table, that's not likely to be a concern here.

 

[harshness]

The roof is metal if that makes a difference?

It absolutely makes a difference. A metal roof may act as a huge reflector. This can be both a good thing and a bad thing.

 

[Bobbj]

The metal roof might be the cause. I noticed if I took the antenna off the roof and walked away from the house with no amplifier I began to receive more channels. Is running coax 150-200 feet too far to run with a pre amp? I’ve read there is dB loss for every 10 ft but I’m thinking I need to move away from the huge metal roof.

 

[primestar31]

The metal roof might be the cause. I noticed if I took the antenna off the roof and walked away from the house with no amplifier I began to receive more channels. Is running coax 150-200 feet too far to run with a pre amp? I’ve read there is dB loss for every 10 ft but I’m thinking I need to move away from the huge metal roof.

When the antenna is on the roof, how HIGH above the roof surface is it mounted on the mast pipe? It might be all you need to do is go up another 10ft or so, to stop the coupling between the metal roof and antenna.

If you do this, you need guy wires every 10ft to help keep things stable.

 

[Bobbj]

Thank you for the reply. I only had it up about 6-7 feet on the mast above the roof when testing the reception. I will have to try to raise it higher to see if this was causing the reflection. There are also some small trees about 30 yards away that could be blocking the signals. I’m still wondering if the roof doesn’t have something to do with the pre amp not working at his location.

The 7777HD has adjustable gain and a lte filter but lte signals are weak in his location. Even on its lowest setting gain it brings in 0 channels vs not using the pre amp which can bring in up to 8 channels. I might get a different amp just to test it out. I know at my location the cm 7777 would do the same exact thing with 0 channels and the 7777hd model made a world of difference. If only he lived on top of a hill haha.

 

[FTA4PA]

When using the same CM 7777 HD and antennas at my bothers house http://www.tvfool.com/?option=com_wr...9038e93212350b
I get 0 channels even on its lowest setting. When I take the amp off I can normally get 4-8 channels which are WJAC and WTAJ which has me confused.
Anyone have any amp recommendations or reasons I could be getting 0 channels with the amp connected ? Thanks in advance

I’m still wondering if the roof doesn’t have something to do with the pre amp not working at his location.
The 7777HD has adjustable gain and a lte filter but lte signals are weak in his location. Even on its lowest setting gain it brings in 0 channels vs not using the pre amp which can bring in up to 8 channels. I might get a different amp just to test it out. I know at my location the cm 7777 would do the same exact thing with 0 channels and the 7777hd model made a world of difference. If only he lived on top of a hill haha.

Just wanted to clarify. At your brothers house are you using your amp that you use at your house? I mean did you remove it from your setup and bring it over to try there or did you buy another of the same model to use at his house? If the latter, maybe the new amp is defective?

 

[Bobbj]

You are correct. I removed the amp from my setup and tested it at his location. The amp is currently back on my setup and is working fine.

 

[FTA4PA]

You are correct. I removed the amp from my setup and tested it at his location. The amp is currently back on my setup and is working fine.

That rules that out then.