Thanks again for all the great advice! I have installed Winegard HD7082 with a rooftop tripod mount, directed at approx 340 degrees.
When the antenna is hooked up without the preamp, I get the following (virtual) channels and signal strengths:
2.1 - 55% (CBS)
2.2 - 55%
7.1 - 92% (NBC)
7.2 - 92%
7.3 - 92%
9.1 - 97% (ABC)
9.2 - 98%
9.3 - 100%
12.1 - 81% (PBS)
12.2 - 78%
12.3 - 80%
15.1 - 75%
20.1 - 60%
20.2 - 60%
28.1 - 87% (FOX)
28.2 - 90%
32.1 - 82%
32.2 - 80%
32.3 - 80%
48.1 - 50%
48.2 - 50%
48.3 - 50%
The major networks, which I am most concerned with, come in great except for CBS. I picked up the Winegard AP8700 pre-amplifier, hoping this might boost my CBS reception, but it does not appear to be working correctly. When I plug it in, my reception actually drops significantly for most channels. I tried unplugging the downlead coax from the mast-mounted preamp and creating a short (as described at the bottom of the page here:
http://www.dennysantennaservice.com/1136577.html), but the light on the power injector did not dim or turn off, indicating that the power is not reaching the pre-amp. Currently, I am using one screw-in in-line coax F-connector near the antenna as the pre-existing cable running up the house did not reach the peak. So the ~15 ft coax from the pre-amp downlead goes across the roof -> screw in in-line F-connector -> coax down the side of the house -> ground block -> coax around the side of the house and through the siding -> indoor wall plate -> short coax to power injector -> short coax to TV.
I know these screw-on in-line connectors can cause problems with pre-amps, but would a single one make this huge difference? I'm hesitant to purchase another long piece of coax when I already have an existing one running up the side of my house to use. Does anyone have any further advice? Thanks!