Bob, I restored an Admiral 26R12 a few years ago. I really didn't have much time to use it and have since moved it to Florida. I decided to get it out and connect to the cable in my bedroom. Heck, why not? Our cable still has a lot of analog stations... starting with channel 2
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I was greeted with no HV and a glowing 6BQ6GT Horizontal Output tube. I figured the oscillator was not running so I just put a brand new 6SN7GTB in it. Bingo! Working well. And, since in the home in Baltimore did not have analog cable, I only had channel 4 working. I was able to adjust the slugs in the tuner for each channel and it actually worked well.
After running for a couple of hours, I heard the set groan and looked at the back. There was a light show inside of the 5U4G. And a not too wonderful smell. (I have spare transformers etc.) So, one of the replacement electrolytic capacitor may have gone south. Don't have time right now to check. But as the Kingfish said, "Always Something!"
Glad that you got it sorted out. I actually look forward to finding and fixing the problem even if it entails opening up that filter capacitor can again.