Question about Distribution Amp with TV Antennas
I have a question about using distribution amplifiers for boosting antenna signals for long coax runs.
I have a new VHF/UHF antenna from RadioShack, rated for metro or suburban use, installed in my attic. I have coax cables running to 2 TVs, one 25' (no splitter) and one 53' (with one splitter at 50'). I have good reception on digital and analogue stations. I intend to add another coax cable of 100' length to reach a basement TV. Figuring such a long run needs an amplifier, but before fishing the 100' cable, I bought a Radio Shack distribution amp (15db) to install in the attic. But when I plugged the antenna input and the 25' and 53' coax cable outputs into the amp, I ended up with *no signal* at either TV. It's not the amp, because I tried a second one with the same result. And the electric supply is not the problem.
What makes this puzzling is I installed the very same model antenna and the very same model amplifier in the attic of my other house (outer suburbs), also connected to the very same cable -- 25' (no splitter) and 60' (one splitter at 50') coax. That house now has good signal, when it had poor signal without amp. So I have two houses with the very same equipment and set-up, and the first house goes from bad signal to good when I add the amp. But the second house goes from good signal to *no* signal when I add the amp. The only difference is the first house is outer suburbs (20-30 miles to transmitters) when the second is close-in suburbs (3-12 miles to transmitters). Both analog and digital signals are affected. Are there some peculiar ground rules about distribution amplifiers for boosting TV antenna signals to household jacks? Any guidance would be appreciated.