Monitors and cross-pulse

For almost everyone, the color monitor isthe portal to the images captured on tape. NTSC video is notoriously unstable. The standard NTSC is popularly known by video technicians as "Never The Same Color" As the messenger of the signal, the color monitor can offer technicians a wealth of information about the video signal as it plays back. if the monitors are maintained and correctly calibrated.

In a remastering setup, the color monitor should have at least 2 video inputs. One will receive the signal that is being processed through the video/audio switcher, VDA, TBCs and Vscope. The other signal should come directly out of the VDA, so that there is no TBC correction to tape signal.

The color monitor should have a cross pulse switch. This switch takes the video signal and re-centers it in the corner. The image is brightened and cut in two by the horizontal and vertical sync bars. In this mode the image is unrecognizable.

By viewing with the cross pulse switch activated you can analyze that large part of the video signal that is used for synchronization.

What will you see? If you are looking at a signal that is passing through a TBC, you should see clear, straight black bars in the center, one horizontal, one vertical. If there is a sync problem between the TBC and the originating video tape machine, vertical rolls may be very subtle. Viewing the signal in cross pulse will reveal the problem. Because the BAVC system allows switching between the same tape signal passing through different TBCs, the cross pulse view of the output will give you the information which will help you choose one TBC over another for the transfer.

The cross pulse switch is useful when viewing a signal on the second video input, as a signal that is not being corrected by a TBC. Without a TBC you will be able to see the skew errors, tracking problems, head switches. Essentially, you will see all the problems that are part of the sync on that tape. Once you know the problems, you will be able to better judge the course to take with the tape. Watching a tape without going through a TBC also gives you an early warning if the TBC is causing strobing or other problems associated with processing old tapes through TBCs.

The playback tape machine, the recorder, the video/audio switcher, the VDA, the TBC, the waveform monitor/vectorscope and the color monitor are all connected in a way that provides the technician with the most efficient method of transferring from the playback tape machine to the recorder.