Originally Posted by JER
Its been my general feeling for quite a while now that for many people reception problems are usually related more to signal quality than signal strength.
The above post by FoxTV indicates how complicated the signal environment can be and how difficult it can be to resolve these kinds of problems without a truck load of test equipment.
Probably the simplest way to avoid a lot of these problems is to get the antenna outside and to avoid amplifiers.
Putting the antenna outside helps reduce the impact of household noise sources. It also dramatically increases signal level and reduces the effect of indoor multi-path.
While amplifiers increase signal level, they always add something (e.g. noise, harmonic distortion, and inter-modulation distortion) that's not actually on the air. A cheap amp can easily saturate on a strong in-band or even out-of-band signal and generate a wide spectrum of "crud" that makes it impossible to detect anything with the receiver. By starting off without an amp, you can make a better determination of what your true signal situation is like. Then, if you're missing some weak stations you can add the amp and see if it really helped.
JER, I agree with your thoughts on amplifiers. I think they are overused to the point of causing problems instead of solving them. An amplifier is the last thing I would recommend to try and solve reception issues. This is based on my last 3 or so months doing field strength tests in our market that has very mountainous terrain. I have received signals from ours, and other transmitters in this rough reception terrain at 75 miles out, and still had plenty of signal head room for good reception using a Clear Stream C2 or in some cases a C4 at only 20 feet elevation.
I have seen this same scenario at many different locations in our rigorous signal testing project. I use a Rhode & Swartz FSH-3 TV Analyzer for RF signal analysis, along with a Sencore DTU 236 transport stream analyzer to look for echo strength and amplitude, and for echo timing to see how far out on the time line the echos are in highly problematic areas. It seems that most of the multi path issues are from reflective objects that are relatively close to the receive location instead of miles out as in analog.