Zenith 5311U / 24MC32 restoration

[bandersen]

Meanwhile, I pulled all the tubes for testing. Unfortunately, careful as I was, the cap broke off the 6JS6 and let the air in

The tube looked well used and may have been weak, but now I'll never know for sure. I have 1,000s of tubes NOS and pulls but had a heck of a time finding a replacement.

As for the others, I check them with a TC-162 and found many had shorts or excessive grid leakage. Luckily, I had replacements for all on hand.




While searching I came across this Servicemaster 3AT2 made in Korea. I think it's the first Korean tube I've come across. Don't plan on using it, just though it was interesting.


Back to the 6JS6 saga. I finally dug up a used one that tested good and popped it in.



Hmm. Nothing on the screen. Let it run a while and slowly the screen lit up dimly with a weird image.


A while later, it got a little better.


I hooked up by Seco meter and found it was drawing less than 100mA. Schematic calls for 225. Time to search for another 6JS6....