7JP4 save

[Tony F]

I managed to pickup this Admiral off of FB marketplace cheap. It does have a cabinet although not in the best of shape and no outer knobs. The fine tuning control is there, but the channel knob is broken in the usual spot. It is missing the speaker. I felt sorry for it and thought it might be good for parts. Upon testing the 7JP4 it showed nothing, I carefully removed the end cap and three of the pins soldered on to the CRT crumbled away. Pins 8,9 and 10. Amazingly the wires stayed with the CRT and somehow broke loose from the solder joint. Closer inspection revealed why. About half of the pins were green with corrosion. Pricing a new socket with shipping would be about $50 (no thanks). I proceeded to remove all of the pins from the bakelite cap and install new ones from a few 8 pin tubes that tested bad. (yes, they are the same size). Using a dremel, some small drill bits and some needle-nose pliers I was able to reinstall the used pins in the old socket. I soldered some wire-wrap wire to the ends of the CRT wires after I removed the oxidation. I used some windshield and water leak silicone around the neck of the tube to reattach the cap. The problem I realized was there is more of a gap between the glass and the cap than there seems to be with regular tubes, so there is still some "play" after it has set. I should have left the old epoxy inside the cap and not scraped it out. Although it is "catch -22" as it was kind of in the way from being able to reinstall the new tube pins. I ended up using a couple of turns of black electrical tape around the cap and glass. Anyway after all this messing around, it now seems I have a good tube, although the cutoff doesn't seem to be the best.
Tony