Horizontal issue

[bigaudioal]

Hey guys, take a look at the below YouTube video and let me know what you think. Been battling this horizontal issue for a week now in the TeleBar. Replaced all the caps and now micas in the set too. Also have done all the resistors in the horizontal. Nothing was very far out of tolerance. Not luck yet. The horizontal drive and horizontal lock adjustments on the back of the set are extremely touchy. Sometimes the picture goes completely dark as it loses synch, which you will see. Have had this issue since I fired up the set and have not been able to correct it so far. Any advice or ideas are much appreciated.

http://youtu.be/hv6j5TscWaY

Thanks.

[Phil Nelson]

Starting with the obvious . . . I assume you have already done the usual swapping of horizontal tubes with known-good ones to eliminate those as an issue? Especially the horizontal oscillator. A tube tester that checks a tube's emission can't necessarily test how it will function as an oscillator. So, a tube might test way up into the "GOOD" zone, yet still be a lousy oscillator.

Just a thought . . .

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[DavGoodlin]

The frequency appears to be dropping, due to the pull to left.
Have you tried freeze spray on the very small capacitors (up to 500 picofarads) to confirm a temperature issue?

Not sure if the vertical roll is a clue or just a side effect.

[rrrhre2s]

Back in the day...

I had a Zenith TV doing something similar messed with it for two days...

Turned out to be the Horizontal Output Tube...

I changed everything (resistors / capacitors) in the Oscillator section No Go...

Changed Every tube in the HV and Horizontal section the set quit acting up then I put the original tubes back one at a time until the problem reappeared.

Have had the phase detector dual diode or tube to do similar...

rrrhre2s

[bigaudioal]

Yeah, the more I am researching, the more I think you guys are correct and it may just be a tube. I have switched them around but my stock is very limited at this point. This week I am gonna break open my other Admiral console with almost identical chassis (same SAMS) and "borrow" the tubes from there to try and diagnose the issue. Know those tubes are good and working in that set fine.

We'll see.

[earlyfilm]

Originally Posted by bigaudioal

Yeah, the more I am researching, the more I think you guys are correct and it may just be a tube.

Probably, but if you replaced the 5% tolerance .0039 capacitor across the Horizontal Lock coil on your Telebar, then if the substitute tubes do not cure the problem, paint a dot on that coil shaft and count your turns and direction (write them down while testing) so you can get back where you started. If turning it one way makes it worse, try turning it the other.

To paraphrase another members sig, "Perfection is hard to reach with a screwdriver unless you have a good calibrated signal generator and a good scope!" However, it this case if you are careful and don't muck it up, you probably can.

James

[bigaudioal]

Happy to report that swapping the Horiz. Mult. 6SL7 tube did the trick!!!! Watching the set going on an hour and a half now. Solid! Did take me a bit to get the Horiz lock, horiz hold and horiz linearity adjustments to all jive, but looks pretty decent now.

http://youtu.be/XyXfRXduqGM

http://youtu.be/qD1ZXij6wvE

NOW IT'S TIME TO STOCK THE BAR!!!!! Thanks again for all the advice and help.