Tweeting Sound and no HV from the HV cage

[Jon1967us]

Regarding a 57 Travler table TV, I had the set going last time I powered it up off the Powerite ( which is the only way I power it up). I made some tweaks prior to powering it today, having changed the Horiz AFC diode and replaced the Vert integrator network with a tested NOS one. I also fixed a short on the Vert lock pot.

When I first powered it today, I forgot to plug in the yoke. Would this have damaged anything?

Now I'm not getting HV on the HV lead at the CRT. I'm also hearing a tweeting sound from the HV cage.

Any insights?

[Electronic M]

If the horizontal osc is far enough off frequency it will not make HV and produce audible screeching. Got a scope to check osc freq against horizontal sync tips in the video waveform?

[Jon1967us]

Well, that's encouraging. I'm hoping it isn't the flyback or something unobtainium.

Problem must have something to do with the horizon AFC diode replacement. It should be oriented, but I'll put the selenium back.

Yes I have a scope. I've never done what you're suggesting but sounds like a plan. I will try it in dual trace mode I guess.

[Jon1967us]

I got the HV back.

The diode I thought was oriented correctly was not. I still would like to check and compare waveforms as there's a fair amount of sync instability.