Low VHF dropout

[Phil Leeds]

I set my parents up with Winegard 7084p two years ago and it is functioning well with a digital tuner tv about 40-45 miles from the tranmitters. In an effort to split the signal to a convertor box and older tv in the bedroom, I added a Winegard 8275 preamp. I first tested it on the newer tv to make sure no signals were overreved. All channels operated properly. I then connected the signal splitter to the convertor box in the bedroom, all channels functioned well with good signal strength. I then shut off the convertor box and ran a channel check on the newer tv and noticed VHF channel 7 (real) pixelated to halt. When I turn on the convertor box, the newer tv on that channel then functions fine. All other channels were unaffected. I verified this effect several times by turning on and off the convertor box and watching the other tv pixelate out on VHF 7 each time it was off. Any theories and remedies for this problem other than just leaving the convertor box on full time?

[winegard]

It sounds like we have a bad connection, a defective splitter, or a bad piece of cable causing a standing wave to fall out on channel 7’s frequency.

(1)Try going from the TV antenna to directly to the AP-8275 and from the AP-8275 power supply to the newer TV set. (2) Check all of the channels and note their performance. (3) Now add only the splitter and check all of the channels again and note their performance. (4) Next add only the cable from the splitter to the TV set with the converter box and again check the pictures on the newer TV set and note the performance. (5) After noting picture quality install the converter box but do not plug it in or hook it to the TV set and note the picture quality on the newer TV set. (6) Plug in the converter box but do not turn it on and once again check the picture quality on the newer TV set. (7) Now turn on the converter box but do not hook it to the TV set. Check your pictures on the newer TV set again. (8) Finally hook the converter box to the TV set and every thing should be hooked up and the converter box should be on.

As you check and hook up each piece of equipment you should find the defective piece of equipment causing your problem.

[Phil Leeds]

Many thanks for the algorithm to run down the problem. Will try it ASAP