21CT55 Screen-Shot Test

[Tomcomm]

Wayne...........Screen-shot # 5 displays only one field not a full frame time. In checking the parameters of that jpg shot I noted it's shutter opening time was 1/13 second or quite sufficient for a complete 1/30 second interlaced frame. It is apparent that line-pairing occurred during screen-shot #5 as you observed. Since all the other shots taken within a few minutes had good interlacing, an anomaly had occurred. Early-on I observed that vertical interlace quality is greatly influenced by the front panel vertical hold manual setting, even when the hold is well removed from causing vertical roll. I considered this imperfection to be of secondary importance and accommodated it by manually tweaking the vertical hold to achieve interlace immediately before any quality screen shot. Apparently, I neglected to tweak the vertical hold before shooting #5. I intend to get into the vertical deinterleaver some day to find out why the waveform differential circuitry is not operating correctly…..Tom