Thank you for the report. Sorry to hear that you didn't get everything you hoped for, but you are doing extremely well with an indoor antenna. The aim of the C2 is not as critical as the 7694 because of its wider beamwidth; that's the trade-off between gain and beamwidth. I had hoped that the greater VHF gain of the 7694 would help you with WHYY.
Is WNJS-DT 22 (23.1) PBS good enough for you?
I reviewed this thread, and can't think of any more good ideas for WHYY. It is your weakest desired VHF channel with a 2Edge signal path which means it is doomed to be your least reliable channel.
I investigated the possibility of second harmonic interference from an FM signal. The center frequency of channel 12 is 207 MHz, so there would need to be a strong FM signal around 103.5, but there isn't.
http://www.tvtechnology.com/digital-...ference/202503
It still might be fundamental overload from FM. Your strongest FM signal is WDSD with a signal strength of -25.0 dBm. You could test that theory by inserting one or two HLSJs in series before the preamp, using the high and common ports. The purists would say to put a 75 ohm termination cap on the unused low port.
http://www.hollandelectronics.com/ca...-Diplexers.pdf
http://www.solidsignal.com/pview.asp?p=zhlsj
Sometimes the combined/separate switch of the RCA preamp has a problem making a good contact in the separate position on VHF.
The only other thing I can think of is electrical noise interference on VHF, which is worse than on UHF. It can reduce the SNR of a weak signal making it impossible to receive. I have a VHF-High signal that barely makes it to an SNR of 15 dB which is the minimum for reception before dropout. I have a signal level meter and was able to measure the strength of the signal and the strength of the noise of the adjacent vacant channel to calculate the SNR.
My Sony KDL22L5000 also gives a reading of SNR and errors of OTA 8VSB and cable clear QAM digital signals in the Diagnostics Screen. Here is a bad signal with picture freeze:
Good signal:
My Hauppauge 850 and 950 USB tuners can give a reading of SNR and errors, but the software isn't user-friendly for me.
http://www.hauppauge.com/site/suppor...l_monitor.html
Sometimes the aim of the antenna for maximum signal strength is not the best aim for maximum signal quality, as defined by SNR and errors. I first learned about this with an Apex DT502 converter box, that has dual signal bars, one for signal strength and one for signal quality (the inverse of errors).
I first aimed the antenna for maximum signal strength. Then, when I rotated the antenna slightly to the right, the signal strength was a little less, but there was a big increase in signal quality.
My point is, if you can find a way to measure signal quality, you can optimize the aim of your antenna.
Most of the indoor signals have multiple reflections that make it difficult for the tuner to lock on to the signal. Some locations are so bad that it has been necessary to put the antenna in a shielded enclosure that is open at the front to make the antenna even more directional to reject some of the reflections.
http://www.avsforum.com/forum/25-hdt...l#post21358820