An update
I'm the only residence with multiple big antennas.
I had to educate the home owners association about my right to deploy an antenna array.
UHF channels still viewable.
Using latest SiliconDust firmware. The firmware update changed signal quality scale.
11.1 (RF 12) is still the challenging channel. Frequent reception failures compared
to 12 months ago. Stacked VHF antenna balun lead wires are breaking down.
Unplugging one VHF antenna drops signal quality by 10%.
I think stacking the VHF antennas is still a win.
RF 12 drops off reception cliff when signal quality drops below 50%
Conditions have changed for the worst of the last year.
Tuner Channel SS SNQ
0 7 ss=96 snq=90
1 7 ss=96 snq=90
0 12 ss=75 snq=58
1 12 ss=76 snq=59
0 49 ss=78 snq=80
1 49 ss=78 snq=81
My plan is to replace the VHF baluns.
I read in another posting that quality external baluns are hard to source
Trim some near branches.
If that does not improve situation, I may look for a new location for the VHF
antenna stack. Keep the UHF antenna at current location on roof.
I'm lucky to receive alternate KNTVHD 11.3 (RF 49).