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Old 01-21-2016, 09:01 AM
Ed in Tx's Avatar
Ed in Tx Ed in Tx is offline
Zenith Walton My 1st TV
 
Join Date: Nov 2008
Location: DFW
Posts: 1,420
Probably the same alignment but you were just hit and miss without proper hookup and procedure. This is something you need to learn how to do on those old machines. I can almost guarantee 100% all of them will need some touchup of the drum and capstan servo alignments.

Needs to be set to the center of the PLL servo range which is what the alignment does, so the drum comes up to speed and locks to speed properly. The head switching point is effected by this too so you may find a close point by watching a known good videotape and adjust the drum servo so the switching is just visible a few h lines above the bottom of the picture. Could also be the 3.58 oscillator or it's trimmer capacitor being off or intermittent. Looked like something was drifting off freq watching that video, until it lost sync completely.
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