Admiral 26X56 restoration

[bandersen]

I put the rectifier back in and slowly power the set up over about 20 minutes. As B+ increase so did the hum in the speaker. B+ should be 300 but measure less than 200 with plenty of ripple. Turns out the main 60uF filter cap was open. I cut it loose and tacked in a new one. That killed the hum but still no reception. Cleaning the tuner and wiggled some tubes and got some clear audio

Eventually, I rediscoveredd and repaired the broken HV lead. HV was pretty weak but at last I managed to get a raster.


I also rejuvinated the CRT which was testing very weak. It's up into the green now, but the raster isn't very bright.

Replacing the horizontal output tube and tweaking the horizontal drice helped a little. I noticed B+ was still well below 300 though. Replacing that tired 5U4 and a couple more electrolytics got it up where it should be. HV is also close to spec.


Gradually, the image got better and better.


Replaced a few weak IF tubes and played with the flaky contrast control and got a decent image. Sync is non-existant though.



Worked on the sync circuit and found the 12AU7 was dead.


This set had the shortest 6SN7s I've seen. Assuming that's even what they are. No markings on them at all!


Replacing that got me solid sync but victory was short lived...