Capturing problems: signal noise and/or field-switching?

[Admiral Falcon]

I've noticed a problem on two capture cards now, across two different computers since February.

Symptoms:
- Some older programs (Get Smart, early Simpsons) appear to be 'jumping' up and down at a regular rate (though the rate varies by program). This is especially noticable when text (credits, etc.) appears onscreen. The problem is pronounced in 352x240 (NTSC in the good ol' US of A), and also appears in 720x480.
- Virtually all channels have a top line of 'static' in overlay mode. However, when viewing a capture of such channels, sometimes this static is captured, sometimes it is not. This may be unrelated to the above problem.

So far, I do not know the cause. However, through several months of experimentation, I do know that it is not any of the following:
- Hardware failure on the Tuner (a second tuner, a brand-new AverTV Stereo exhibited the same problems)
- Cable-TV signal problems (hooking the cards up to an antenna produced the same problems on the same shows)
- Local EM interference (The cases are EMI shielded from outside interference, and the problems persisted even after I removed my ISA-based radio card, which was thought to be a source of interference)
- Computer-specific incompatibility (The card exhibited the same errors on my new computer as it did on my old one)
- Cabling problem (used a diff. coax cable for my antenna connection)
- Coax-connector failure (composite-RCA exhibited the same problems)

The card is an ATI TV-Wonder VE, the service is basic cable (no access to scrambled channels, so no box). It should be noted that in February, I switched over from digital cable to the analog basic I have now. Maybe the broadcast from both terrestrial and cable stations is such that without a box, the signal is crappy enough to mess up a tuner card? Image is sharp and clear on all TVs connected, though. Does the box do some sort of processing to output a cleaner signal, or does it rearrange the signal in some way? Or am I just dealing with some weird variant of IVTC? The card did not do this a year ago when I was running Windows 95. Did the switch to WinME cause some software errors to cause these problems?

As of now, I still have no clue as to why my card is doing this. It has been five months, and nobody has been able to give me any idea as to what may be causing this problem. Sometimes, the picture jumping is so bad as to completely spoil a capture and render it unwatchable. Any help would be *very* greatly appreciated.

[Admiral Falcon]

I just experienced the same problem in a cap of a new episode of Futurama.

I have compiled a two-frame GIF animation showing how this problem affects my captured video. Doesn't it look like the signal is jumping up and down a half-field or so? This was taken from a 352x240 capture.

Any help would be greatly appreciated, as I have not had *any* answer from any of my posts about this in the past five months.

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