Signal Loss

[LoTech]

I have a Winegard HD 7084P set up for two channels (TVFool Report). I get WYMT and WKHA with signal of 94 and 92 on my Coolsat 8000HD. Unfortunately my RCA television doesn't have a signal meter. Every night between 8:00 and 9:00 my signal goes to zero on the Coolsat, and I am unable to lock the channels on my RCA television. It sometimes stays this way a few hours and then back to normal. I have the antenna hooked to a Radio Shack 15-259 preamp and then through a diplexer to my Dish Network cable into my house. I know this isn't ideal, but the cable was already run, and I get good signal through the diplexers. Does anyone have an Idea why the Signal would go at about the same time every night?

Antenna --> Preamp --> Ground Block --> Base Unit --> Diplexer -->Dish Cable --> Diplexer --> TV.

[Tower Guy]

Originally Posted by LoTech

Does anyone have an Idea why the Signal would go at about the same time every night?

One of two possibilities;
1. The signal propagation changes as it cools down when the sun sets.
2. There is interference from equipment that operates only during the evening.

Your signals are very weak and either cause is just as likely.

I'd monitor the signal strength meter on your TV set. If the signal quality drops slowly, consider propagation issues, if it drops suddenly, consider interference.

Propagation issues can be helped by raising the antenna. Interference should be tracked down by turning suspect equipment off.

[LoTech]

One of two possibilities;
1. The signal propagation changes as it cools down when the sun sets.
2. There is interference from equipment that operates only during the evening.

It drops off all at once from signal quality in the 90s to 0. What kind(s) of equipment/interference could cause this? I live in a rural area with no kind of equipment around for miles.

[Tower Guy]

Originally Posted by LoTech

It drops off all at once from signal quality in the 90s to 0. What kind(s) of equipment/interference could cause this?

Do you have a street light? How about a touch lamp?

To troubleshoot interference unplug everything in the house or turn off the branch circuits except for the TV set and the amplifier. If that fixes it, turn things on one at a time until the problem recurs.

If that doesn't work consider power line interference from outside the house. To trace it, tune your car radio to 530 on the AM dial and listen for a loud buzz. The buzz will be loudest close to the source of the problem.

Another potential source of a problem is the preamp itself. It could fail when it gets cooler, but that doesn't easily explain why the signals return later at night. If the preamp is oscillating, it could change frequency with temperature enough to explain the issue. The brand of preamp that tends to oscillate is an older Radio Shack design.

In one case I found that a neighbor's car had an FM transmitter interface for his satellite radio. TV reception was bothered only if the neighbor's car was home.

[ADTech]

If you can set your clock by the loss of interception, you can be assured it's something that's on a timer.

Dusk to dawn lights are another common source although they tend to vary the timing of the interference slightly each day.

[LoTech]

Thanks guys. I'll do a little investigating tonight to see what the problem might be.

[LoTech]

I think I may have figured out the problem. I have a water softener/filter that kicks on about that time every other night and stays on about an hour. I'll do a little more experimenting with it, but the filter is about 20 feet from my antenna, and about 30 feet from the amp. I'd say its a prime candidate for the problem.

[Tower Guy]

Originally Posted by LoTech

I think I may have figured out the problem. I have a water softener/filter that kicks on about that time every other night and stays on about an hour.

I'd reset the timer to backwash at 3 AM.