1966 Zenith 20X1C36 failed vertical output transformer

[Dave Drez]

I've been working on a restoration (with a my friend Roger) of a Zenith 20X1C36 chassis. This set was made in 1966 with a very unique and beautiful "mid-century modern" cabinet. The chassis had come a long way which included a NOS 25XP22 CRT. Just when things looked like it was up and running - the vertical sweep failed dramatically. It was clear that there was arching somewhere - both the picture and sound made that obvious.

Long story made short- the vertical output transformer shorted directly from the primary to one of the secondary windings that feeds the dynamic convergence circuit. The good news is that it is only one winding in the secondary. It took me a week to figure out all the details because the physical damage took place in a distant part of the set. That's where electrically it was shorted to ground. Once I lifted that winding out of the circuit, the set started up perfectly - minus the dynamic convergence circuit.

I have looked all over the usual places for a replacement vertical output transformer but have had no success. I was wondering if there would be a way to "hot-rod" an audio transformer to one of the other secondary windings that are working, and feed that output to where the failed windings go? The impedance in these secondary windings are small 1.3 - 6 ohms in places so I though of an audio output transformer wired backwards. Any ideas??

This is the Zenith part number and the after-market replacements in case someone might have one! I'll buy it!

vertical output transformer:

Zenith 95-2470
Thordarson 26s60
Stancor VO-714C
Triad A308X

Thanks for your help!

Dave

P.S. The picture is before the transformer failure...