Auction Admiral works but CRT bad.

[Eric H]

I tinkered with the 1965, 23" Admiral Combo tonight.

First up, the Horizontal wouldn't lock, the frequency wasn't even close.

After trying to jump various caps I checked the Horiz AFC diode, this is that double diode with three pins, on this set it plugs into a socket just like a tube.

It wasn't shorted but the resistance was different for each side and it was high so I cobbled one up with common Silicone Diodes, plugged it in, adjusted the Horiz slug and it locked right in.

The picture was really dim and washed out though, I tested it again with my Accurate Instruments 257 Tube Tester and it showed absolutely zero emissions, turning the heater up to 12.6 volts (the next step on the 257) made the needle crawl up to the good range but it dropped like a rock as soon as I put it back to 6.3,

I thought the B&K tester was broken but it turns out the tube was really that dead.

I hooked up the B&K again and put it on "Super Rejuvenate" but nothing happened, I turned the heater voltage up a bit and tried again, this time there was a shower of sparks inside the neck and the emissions jumped up to the top of the scale!

It works, nice and bright now, the contrast is a little weak and there's some issues that new caps would fix but first I need to locate a new 23CP4A.

This will be a nice watchable set when it's fixed so I think it's worth the effort to find a new CRT.

[ctc17]

Wow you are lucky it rejuvenated. I have done that a few times and burned off what little was left leaving me with nothing. Shottkey diodes work real well as a replacement for those phase diodes. I just use the regular switching power supply ones.

detector diode failures have had me pulling my hair out several times.

[dieseljeep]

That set is closer to being a 1960 model. I think that was the first 23" model they made. The radio part should be tubes also.

[John Marinello]

Are there any subs for that CRT?