Not sure if an amplifier would help

[sparko]

Hello:

I recently set up an antenna for my mom. It's the Antennas Direct C2-V-CJM ClearStream 2V UHF/VHF. It's in the attic, about 20 ft or so above the ground. She is located up on a hill and gets pretty good reception as is. The signal is split to two different tvs. One cable run is less than 15ft. The other is closer to 50ft. The reception on both tvs seems to be the same, regardless of the cable lengths.

The signal analysis report is here:

http://www.tvfool.com/?option=com_wr...d24375e0f630f4

We are in Connecticut and I have the antenna pointing generally towards the New York city area (around 230 degrees). Channel 11 (WPIX) comes and goes as does channel 7 (WABC), but is a little more reliable than 11. She would love to get channel 21 (WLIW) but I have had no luck with that.

I've tried just turning the antenna a bit to get 11 and 7 in better with no luck. We have found, though, when someone is near the antenna, 11 and 7 both come in much better.

I was wondering if it would be worth adding an amplifier to her set up. Would it lock in channels 11 & 7 and maybe even pull in channel 21 along with some others? Since she gets pretty good reception otherwise, would adding an amplifier cause more problems with over amplification?

Any advice would be appreciated. If an amplifier is recommended, can you suggest a make and model? Thanks.

Patti

[timgr]

Are you stuck on leaving the antenna in the attic? I would try moving the antenna to the roof temporarily to see if reception improves. Attics are a poor place to site an antenna, typically, and only workable if the TV signals are strong to begin with.

A preamp at the antenna can help with weak signals that do not have the strength at the antenna to make it through whatever cable run and splitters you have. The amplifier actually reduces the quality of the signal at the antenna by adding some noise of its own - but often that is a worthwhile trade for the higher signal amplitude, especially with long cable runs and splitters. The splitter cuts the signal strength in half, but does not add a lot of noise. You could try running the short cable directly to the nearest TV and see if you get any more stations - that would give you an indication if adding an amplifier at the antenna would be helpful.

[sparko]

Thanks for the reply.

Yes, the antenna is inside because she lives in a condo complex that won't allow antennas on the roof. We might be able to put it outside where her Dish currently is, but it's lower on a porch post. It seems to be a trade off (higher, but inside vs. lower, but outside). Next time I am over there, I will try it, though.

Initially, when we were testing the antenna, we just had one run from the antenna to the closest tv. No channel 21, but with a quick scan, everything seemed good. Then we tried the splitter, and still, with a quick scan, everything seemed fine. After we went home and my mom started viewing the tv via the antenna on a regular basis, she started noticing some issues with channel 11 & 7. I don't know if they would have occurred without splitting the signal or not. I guess the only way to find out is to change the wiring and let her view it for a week and see if she notices an improvement.

I am wondering why there is improvement in reception for channels 11 & 7 (in particular) when someone is up near the antenna. Is this some grounding thing? Is there something I can do that would simulate someone standing near the antenna?

[timgr]

Your body is electrically coupling with the antenna. That combined with the geometry of the attic and whatever metal objects are nearby is changing the characteristics of the antenna.

These antennas (antennae?) are designed to operate best in free space, on a vertical mast. So I'd think you shouldn't see an improvement when you change the loading by standing next to the antenna. You must be counteracting some other detrimental loading that is present in the attic.

That said, is there room in the attic to move the antenna around? You might find a sweet spot and orientation within the attic that works better. But predicting antenna performance in an attic is difficult - too many variables. In the air is much easier.

It's hard to judge whether you have a strong signal or just an adequate signal without a tuner that tells you that, or expensive test equipment. Digital TV is typically an all-or-nothing proposition - either it works and the picture is beautiful, or there's not enough signal and you get nothing. If you are on the border, you could see pixelation or complete drop-out occasionally. Also there can be seasonal changes due to water or snow on the roof, or trees.

[timgr]

Re WLIW, I would not be too hopeful. It's pretty far down the list, at 8 dB noise margin and is 2-edge. And there are co-channel and adjacent channel warnings. This is close to the limit for what you can get with an antenna mounted in free air, that does not have the attenuating building materials around it. A 2-edge signal means that the TV signal has to be diffracted twice around an edge in the landscape in order to be received.

But you might get lucky. I'd run another report at the height of the porch and see how much signal loss to expect. Then if it doesn't change much and you can point at NYC and there are no buildings or trees or other obstructions in the way, you might get WLIW.

[Jake V]

How easy is the access to the pole that held the dish antenna?
How close is the old dish antenna to the porch?

It sounds like it would be pretty easy to take the antenna out there (assuming you could aim it towards NYC) and try it to each TV with a single length of new coax before pulling any cables. It's the easiest way to test it. The C2-V-CJM does not have much gain on VHF, so outside should be better.

For WABC-7 and WPIX-11 an alternative is to pick up a separate, more powerful VHF antenna and connect it to where the VHF connection for the C2-V-CJM now connects. Something like an Antennacraft V5713 or V10713. WLIW probaby won't be possible in the attic (esp since it's in a different direction).

[sparko]

Well we tried setting up the antenna outside by swapping it out with the Dish that was already there. Unfortunately, there did not seem to be a big improvement having it outside, and we still could not get WLIW (21).

My mom was pretty much happy with the channels she got when the antenna was inside, with the exception of losing 11 from time to time. So we headed back to the attic and tried to find a sweet spot for the antenna. We set it in a new location that also put it at the highest indoor point it could be. So far, everything seems to be working well. Channels 7 & 11 no longer pixelate or drop out. A couple more channels come in as well. We'll see if any issues arise over time.

Thanks for all the replys.