The website you are referring to is located at:
The Sacramento and San Francisco stations are NOT located in the exact same direction. That is why you need a highly directional antenna with a very narrow beamwidth. You can separate the locals from the Bay Area stations. You can "pick up" the San Francisco stations when the antenna is pointed towards the Sacramento towers, but you can get a STRONGER signal when turning the antenna towards Mt. Sutro (San Francisco towers), and at the same time, REDUCE the local signals, thus giving you a stronger signal with less interference. To help clear up the confusion between coax and twin lead -- First, twin lead must be installed properly - not touching any metal to say the least, as it should be a few inches from any metal. It's not good to install twin lead between walls, etc. As far as loss goes, coax is consistant regardless of the weather. Twin lead losses can be greater than coax during wet or damp weather. To have low loss, twin lead must be dry. Also, twin lead is more suseptible to breakage during high winds. You want the SAME lead in all the way from the antenna to the television. Don't mix twin lead with coax. You might get excellent reception of the local channels, but it can make a big difference on distant reception. IF your antenna is high gain on UHF, has good directional characterics, you should easily get channel 19 from Modesto UNLESS there is a mountain near you blocking signals from that direction. However, channel 14 in San Francisco is also Univision. I have picked up weak signals from channel 14 even here in Fresno. I can tell you this - When living in Fair Oaks, I had the largest Channel Master UHF/VHF antenna available, installed on a 40-ft mast with rotor and I could NOT get any signal on channel 14. But my neighor had a cheap, small antenna mounted on the chimney and got a good signal on channel
- Higher is not always better on UHF. Also, ANY bad balum OR even twisting wires combining coax to twin line can totally wipe out some UHF frequencies.