: Grigor Rasputin is not the thread starter, but his problem is similar, so he has posted at the end of this old thread. He is talking to jhe in post #45 above who is in Lexington, MA.
I think you should have started your own thread GR, but maybe this will work. Don't be surprised if admin separates your post out to a new thread.
Welcome to the Forum. Your tvfool report for Burlington looks like this:http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d1349de0acca553
A tvfool report with your exact address would be more accurate, but you probably can't post an active link yet. You can, however, give us the URL in bold type near the top of the report and we can post it.
Is it really possible that the loss of all channels is attributable to the
overdriving of the 7777 pre-amp?
Yes, quite likely. It is also possible that your tuner is overloaded.
There are preamps that can tolerate higher signals levels than the 7777, but you still need to be concerned about the tuner.
The strong Boston channels are directly in line with the Providence antenna farm, in
That makes it a very difficult problem to solve, because your local signals are about 35 to 40 dB stronger and in the same direction.
Don't get your hopes up, but one possible idea would be to insert an attenuator between the antenna and the input of the preamp. Adjust the value of the attenuator (perhaps 10 to 15 dB) to eliminate the overload, but still retain sufficient gain to help you with the Providence signals. You could also try an attenuator between the output of the CM power supply and the TV. The best location for an attenuator would depend upon which is being overloaded first, the preamp or the tuner. Without even adding the antenna gain, your strongest signal (WMFP at -24.2 dBm) plus the preamp gain, puts you at the overload point of the tuner.
ATSC Recommended Practice:
Receiver Performance Guidelines
Document A/74:2010, 7 April 2010
5 RECEIVER PERFORMANCE GUIDELINES
A DTV receiver should achieve a bit error rate in the transport stream of no worse than 3x10E-6
(i.e., the FCC Advisory Committee on Advanced Television Service, ACATS, Threshold of
Visibility, TOV) for input RF signal levels directly to the tuner from –83 dBm to –5 dBm for both
the VHF and UHF bands.
After you got through messing with attenuators, the results probably would not be as good a just removing the preamp, which would be a lot easier. There is an expensive solution which involves separate antennas, two preamps, custom bandpass filters for CH49 and CH51, and A/B switches.
What antenna are you using, and where is it located?