don't let him do any more work

It must be an electrical issue.
What's on that "certain breaker" ?
The Central Air Conditioner ?
I'd check with an electrician.

I concur. Not signal related. The fact that the interference appeared when viewing a tape confirms that.

Now, you may have needed the antenna anyway but, I'll bet it won't fix the afternoon interference.

Call an electrician.

Well, I'm going to let him put up a new antenna, rotor and amplifier, but I've accepted that its not going to help the problem. I wish I could go back in time, but I can't, and I feel that I should have told him that I'd get back with him. But I said okay, and he's ordered the stuff, so I feel like I need to stay with it.
There's a bunch of small things on the breaker.......a radon fan, flood lights, bathroom lights, closet lights.
Oh well. Live and learn.
Thanks for your help.

I'm trying to think of something else on that breaker that could be working during the heart of the day.

Do you have a thermostatically controlled attic fan?

We have a whole house fan in the ceiling of our living space, but we don't use it.
I think I should have been more thorough in going through the house and figuring out exactly what's on that breaker.

This interference started up around 8 years ago, and I've been trying to think of what was changed around that time. My husband reminded me that we got a new radon fan in the attic around then, but its nowhere near the coaxial cables going to each room. It is on that circuit, but we unplugged it once, and it didn't change the interference.
It would need to be something that's on every day during that time in the summer, and there just isn't anything that's consistently on. I do have 2 small watergarden pumps on all the time, but they aren't on that breaker.
Would a dead antenna rotor cause any problems, if the control box is unplugged?

We live out in the country, without any close neighbors. Could something from a neighboring farm be causing this?

We have a dosing tank with a pump after our septic tank, but its on a different breaker.
We have a geothermal heating and cooling system on different breakers.
Can't think of anything else.
For awhile I started thinking it was the actual sun shining on something because on cloudy days, when it was just as hot, it wouldn't happen as much.
We do have a doorbell that's in the sun during alot of that time. Not sure what breaker its on.

I'm stumped.

Hmmmmm.....I just did what I should have done before I even called the TV guy..........I turned off the breaker, and walked around and saw what didn't work any more. The door bell is on that circuit too! Its in the sun in the afternoon.
Could it just be that???? Dang, and the TV guy is on his way with hundreds of dollars of stuff.

P.S. How would I disconnect the transformer to the doorbell? When I take the lid off, there's a white and a red wire connected to screws. Would I just detach those?
Am I barking up the wrong tree, or is it possible if the doorbell button outside is heating up and malfunctioning, that it could somehow cause interference?

Several years ago I had a similar problem with severe static on a shortwave radio that was there all the time.
I took an AM transistor radio, tuned to a spot on the dial where there wasn't any station, and went around the house with the radio and tried to find out what was causing the interference. Nothing seemed to be causing it.
I finally went out to the power pole and could still hear the static. I walked down the power line and after passing two houses down, the static disappeared.
I went back and stood under the transformer serving that house and could hear the static again. I went up to the electric meter for that house and could hear the static.
I talked to the neighbor and he let me come in to try and track it down. I was able to trace it to a defective door bell transformer in his basement. He had the transformer
replaced and that fixed the problem.
Even though there was a transformer on the pole in our back
It turned out both of our houses were fed from the transformer in his back yard.
If you have a small radio, you could try the same thing. Moving around the house with it, the static should become real loud when you get near what ever is causing the interference. If you don't have a battery operated radio, you could use a long extension cord to help you move around the house.
Although the problem seems to be heat and time related, there's always a possibility the circuit beaker itself could be arcing.

Thanks Jim.

Things that cause interference:

Any electronic device can go bad and generate interference. Unplug to verify.

Circuit breakers. Replace if suspect.

Fluorescent lights (famous for it).

Power lines and transformers. Use the AM radio trick mentioned above.

Fans. Disconnect to test.

GFCI and ARC fault devices. These can be "time" sensitive if they are mounted in or to a wall that gets direct sunlight.

Fencers. These are the boxes that power electric fences.

Any loose electrical connection. If the connection is loose and current is flowing through it, interference can be generated.

All that said, it sounds like it is something on that breaker, or perhaps the breaker itself. Is the breaker box exposed to the sun at any time. If it is, it should be checked for loose connections by someone who won't fry himself. The breaker should also be checked.

And yes, get a new TV guy.