My saga in getting good OTA reception here in Camas continued and I thought I'd share more successes.
I live at some elevation in Camas. My struggles come from an adjacent 5-acre woods next door that are thick enough to prevent me from seeing the transmitter lights. The trees in these woods are very thick and numerous.
I originally had success with the HD-1080 mounted on the side of my house receiving on a Tivo HD and a Sharp 32" TV. This was solid for quite awhile. After purchasing a Tivo Premier and a cheap little kitchen TV, bad reception occurred with both of those on 12.1, 2.1, and 6.1.
Reception improved radically by switching to a CM-2016 (still on the side of the house). Alas, after a couple of good weeks, 6.1 started becoming temperamental on the Tivo Premier and cheap kitchen TV again.
Since I had the two antennas, I played around with combining them. I understand EM wave theory and know how joining waves has all sorts of interference issues. But I had to try. I was getting desperate. I combined these with an antenna splitter in reverse. On my first try I saw incredible improvement on all channels. Everything jumped 10 points. All channels on all receivers were receiving perfectly! I was exstatic!
Alas, when I did my permanent installation a couple weeks later I lost 6.1 completely. The main difference was cable lengths. I looked up what wave lengths we're dealing with, about 2'. This is good as it gave me the idea that short changes in cable lengths could have a huge effect.
I cut myself a few small cable lengths (1', 6", and 3") and experimented adding various short lengths to one antenna and the other. Surprisingly, simply adding 3" dramatically improved matters. Although some of my 98s dropped to 87s. My disasterous 50s levels increased to 70'ish. I again found a good happy medium such that all channels were high enough to be received perfectly by all receivers in the house.
I completed my permanent installation last week and now finally, hopefully, have our five TV receivers forever happily receiving the PDX stations. BTW, we're only interested in the main networks (2, 6, 8, 10, 12, 32, 22/42, and 49), so I didn't measure or tweak for others.