Going to try your skema with 1 preamp and Chan 8 disconnected from my OTA system.
So if Chan 7 works I might need to get tinlee to build ac7 injector?
Thanks so much for your help! I learned a lot about stacking VHF's in opposite directions that I don't need rg6's to be the same length...

because maybe 7's sporadic signal is being cancelled out..