I noticed that as I swing my antenna toward my TV transmitter the picture got worse, not better. Optimum results were off boresite. The wiggly line pattern looked like the horizontal and vertical bars of synchronization pulses from another TV station. I assumed it was overload from the closer transmitter of TV channel 4.
To test this, I screwed a 20 dB attenuator on the co-axial transmission line. This under $2.00 device reduces signal strength on all frequencies to 1/100th power. If the problem is overload, and if the desired signal (my channel 5) is more than 100 times that needed for good reception, the signal would clear up. You can see the results below. Here we have 2 captured images off my home antenna. I made the problem worse to better show you overload by swinging the antenna about 10 degrees away from channel 5 and toward channel 4. It happens that a lot of South Anchorage outdoor antennas are pointed in the wrong direction (for channel 5), and may suffer the same effect. The leftmost is channel 5 with no attenuator. The middle picture is with the attenuator, nothing else having changed. To the right is a photo showing the little attenuator in line with the FM trap.
My TV set, which is VERY subject to overload is an expensive Mitsubushi CS-27470 Serial No. 514703. All images captured off my home antenna are captured from the video output from this TV set. I also have a Zenith wireless cable box, which seems a bit better able to handle overload.
If your reception is suffering from overload, you will have to buy a TV or VCR better able to handle overload (pretty tough as they won't give you that specification!), use the simple pad I have shown here (yup.... you gotta screw it in and out for better reception), or you have to live with it. I can live with it on channel 5 reception, as I can turn my antenna remotely slightly east off the peak signal, thereby reducing the offending channel 4 signal to a tolerable level. You see, the roof rotator pays off again!