Lets Talk Sync and Sync Separation!

[reichsrundfu]

Ok, well I'm not using any ref modulation other than the cable box supplied by RCN. It's a Motorola switchable between channels 3 and 4. I have it set for channel 4 but it really doesn't make a difference. The coax cable runs from the cable box straight to the antenna connections on the Ty's. In the case of my Predictas I have the antenna input switches set to "local" since switching to distant would overload the front end of the sets.

Depending on the channel I'm watching, the trigger can be either switching a scene or going from program to local ad spots. This is true for both the Predicta Barberpole as well as the Zenith Mayflower, along his with the Zenith, the picture doesn't roll but rather drops down so the bottom of the actual image meets the bottom of the CRT. And of course remember that this only occurs with channels that are not transmitting pure 3/4 aspect ratios, such as CNN for example which transmits in HD which is down converted in the same HD aspect ration but in standard definition.

My gut is telling me the issue is at RCN and not really within the TV sets. There's something perhaps in the blanking bar that is going out especially when the tv scene is a very dark (nighttime image) or when switching to local ads that the test aren't liking, especially since the sync is all time based on these old sets.

I think I'm wondering if there is anything I can do to the input signal to get around this? I'm already running the signal thru one of those little boxes which eliminate those copy guards which now and then I'll see on a copy protected DVD. It does a really great job on those DVDs with strong copy guard, but I had kinda thought it would block any weird digital codes that RCN may be inserting to the blanking bar that may be affecting the Tvs

Any thoughts?...

George