my next door neighbor's house is close by. other than that i don't have any hills or other structures near by. im not sure what you mean by noise or multi-pathing. i will check that out.
Multipath is just that - the signal reaches your receiving antenna by multiple paths. The paths are of different lengths thus the signals reach your antenna at slightly different times. Two equally strong signals that arrive slightly out of sync (more exactly, slightly out of phase) with one another can in the extreme case completely cancel themselves and the result is what you see, or rather
don't see - a dropout. The signals' paths and their relative strengths are ever varying in time and space, and what you receive at your antenna is their convolution. In the case where your "primary" signal is not significantly stronger than the interferring signals you will see periodic pixelations and drop-outs as the multiple signals reach a high enough level to cancel the primary signal to the extent that the receiver doesn't have the "clean" signal needed to resolve into your picture/audio. Usually the primary signal is the one coming directly from the transmitter and the interferring signals are those bouncing off mountains, buildings, trees, your neighbor's house, etc. A good directional antenna can accept the primary signal and largely ignore the rest. (Their "gains" at off-axis directions are significantly lower.) Sometimes a bounced signal will be stronger than your primary signal, especially true if an obstacle is in the direct path. You might be able to take advantage of that by pointing your antenna off-center of the direct signal.
Multipath is confounding. This is why we caution that in many cases adding a preamp to boost signal strength is not the answer as that can't solve the fundamental problem and often adds additional problems such as noise. In the analog days, multipath always appeared as ghosting of some intensity and you could "fine tune" your equipment by reducing the ghosts. Today since it's almost always "all or nothing" with digital signals, the problem is not so easy to solve. Rotating your antenna slightly while looking for fewer dropouts is about the only way unless you can get your hands on a signal analyzer.
"Noise" in this context can be radiated RF energy from other sources that adds into and perturbs your signal, or it can also be the added "thermal" noise of any amplifier, an artifact of the semiconductor amplification process itself. An amplifier's "noise figure" is the measurement of that detractor and lower is better.
Hope this helps...
