CTC-4 Director 21

[old_tv_nut]

I don't have the SAMS, just the schematic that's on earlytv.org (RCA?). If "L86" on SAMS is the output of the 3.58 MC oscillator (T115 on the earlytv schematic), then you may be killing the oscillator when tuning too far. If all the bars suddenly go to the same greenish hue, that can be an indication that the oscillator stopped running on some chassis (I'm not certain about the CTC4).

Edit: we crossed posts - glad you have it working.