Kineskope frame rate

[old_tv_nut]

Originally Posted by DVtyro

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For black-and-white version, have anyone thought that the second track should start at the end of the film, so it would work like a regular audio tape: play track 1 from the beginning to the end, then switch to track 2 and play in reverse. This way you would get 50 minutes of moving picture with just a small blip in the middle.

That's an interesting idea, but it would require the extra complication of reversing the vertical scan of the flying spot as well as the mechanics of the player, so I guess Dr. Goldmark and the CBS crew didn't think it was worth the trouble.

In the player the film was pulled across the scanning gate by a capstan that was just after the gate and well before the takeup reel. It seems to me that wouldn't work to push the film backwards through the gate.[I just realized that I don't know how auto-reverse audio cassette players work - have to look it up.]

Also, reversing might have caused secondary problems in recording the master. The sensitivity of the master film to the electron beam changed during the recording due to outgassing of the moisture in the film, so the exposure had to be changed gradually during the recording. CBS never got this totally under control. It was one factor that caused poor yields of good films. Doing this forward and reverse could be a further issue.