Strange 622 TV2 modulation problem

[Fredinva]

I did an up-grade for a golfing bud and we had a heck of a time with tv2 modulation. At the store we generally move off of tv2 air ch 60 default because we have found that a lower air channel 22, 25, etc. will result in a better (snow free) picture. Ok, we start at Air 22, appears to be no problem. We don't use air 21due to a local channel which by the way is low power.
Next day, he calls, says; 'a few channels are snowy, 299 fine, HBO300, 301, 302 are snowy, 303, 305 are fine. Also found 105 is also a bit snowy. What the heck, why some and not others. We tried about six different air channels.
I change out diplexers - same problem.
Another tv at tv2 location - same problem
another tv at 622 direct from tv2 output to 2nd set - seemed ok, but difficult to confirm due to small pic size.
Now I'm thinking we have either a cable problem or a possible bad 622 modulation.

So, last night he calls and said he tried Air 21 - problem has gone away.
This whole thing was wierd - anyone else have anything similar??

fred

 

[rcdallas]

Does he have a VCR connected to the 2nd television? If so he could have turned it on.

 

[SmityWhity]

Another tv at tv2 location - same problem
another tv at 622 direct from tv2 output to 2nd set - seemed ok, but difficult to confirm due to small pic size.
Now I'm thinking we have either a cable problem or a possible bad 622 modulation.

I take it the "Another tv" and the "another tv" were two different TV's. What about using the same TV at TV2 Remote Location and at TV2 Local Location to see if there is a difference?

As you said, maybe bad/low quality cable between 622 and Remote TV. Or, that coupled with interference from a VCR or other device.

Maybe remove the attenuator - if installed.