No Horiz Oscillator on Zenith Porthole- Solved!

[Eric H]

I've been working on this one for a while now off and on. Model 28T964 and I'm stumped.

I've done a partial recap, mostly around the Horizontal section trying to get the oscillator running but no luck.

The problem seems to be at the oscillator tube itself, I have some voltages that are off, particularly the -18 at pin 5, it's at zero.

The resistance on the Horizontal Osc coils seem to be okay as far as resistance but the board they are on is dipped in Beeswax making it most unpleasant to work on, not much there other than the coils except a couple resistors and some caps, I replaced the one paper cap, the other two appear to be Mica.

Voltages at V22 are
Pin
3 = 80
4 = 142
5 = 0
6 = 448
8 = .6

The Horizontal Discharge tube (V-18) is also missing it's grid voltage at pin 4, it's .5 where it should be -20, I suppose that's because the oscillator isn't running?

the Power supply hasn't been recapped but seems to be working OK, I subbed the one out of my Mayflower set and it made no difference either.

The only Can Cap I've re-stuffed is C-4, that was because it was getting hot, the others are running cool, but of course I could be wasting my time by trying to get it working without changing the rest, I would like to get at least the HV running though to confirm the flyback is good.


Link to Sams here Sams is for a 28T963 but seems to be identical.