ADtech,
Nope, just the one 24" TV.
( I know, "why bother?!")
Starting with the diagnostics: This TV will not let you tune to a digital channel it has not automatically detected. So I cannot tune to 9.1 go to the diagnostics screen and tweak the antenna.
My only choice is to tune the antenna, run a several-minute auto search and see if it finds it. I tried for hours to get 7.1 or 9.1 when I lived in Aurora (20 miles closer to the Tx) and never hit one. I tried for an hour or two when I moved here in May with no joy.
I tried again tonight using your lengths and got a hit on 7.1 and can see the pic and sound when I capacitively load the antenna with my body. So the demod works OK at VHF. I can only assume that the Rx sensitivity in that band is much poorer than UHF, or that both my antennas suck. One is a TERK. The one I got a VHF connection on tonight is an APEX.
Going to diagnostics on 7.1 I see signal strength 82, can peak the SNR to 26 dB,no errors, AGC 112%. (Is that like 11 on an amp?)
I tried shortening the antenna an inch at peak angle, but the auto detect still did not see 9.1.
Thanks for the pointer to the spec. Can I take this to mean that I need more than 15.5 dB gain pattern difference on the same channel to freely combine the two UHF antennas?
I also need a VHF-hi antenna. Is there a cheaper alternative to the Comet CF-4160J for a diplexer? ( It does look like a good one, but N-type connectors don't match F81 consumer connections.)
I really appreciate your patience.
Don