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Old 07-07-2018, 03:23 PM
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Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,758
Getting back into it again. Thanks to Dave, I now have a good 21AXP22 in it. My brief glass conversion proved to be easily reversible...The most time-consuming part was patching a hole in the CRT shrowd that appears to have been chewed by mice...I filled that with clear silicone caulk and it is hard to tell it ever had a hole (at least from the outside).

I decided to swap the rectifier tube socket contacts in the 5U4 sockets. They were making poor contact (sometimes the set would power up and not have B+ until one was wiggled) and the heater contacts were getting heat discolored so I swapped the 4 unused contacts on each socket with the 4 used ones and tightened the new ones so they make good contact...It used to be I could barely see the 5U4 heaters glow now they glow properly.

Got the new AXP installed yesterday, and finally got to the yoke issues. The yoke cover and the sides had rotted. Approximately 1/4 of the side of the yoke was gone, the bottom half of the side was just hanging by the wires that pass through it. I got a ~2-3 quart plastic paint container from ACE hardware. Below the top ~1/2" of the container the diameter was too small to go around the yoke properly and the yoke sides had to be taller than 1/2" so I sliced strips from the side of the bucket with 'teeth' coming out the bottom of the strips, wrapped the strips around and melted the two strips together to fuse them into a ring that enclosed the remains of the old sides of the yoke. I then bent the teeth under and slipped them into gaps between the windings and structure and glued them in place. I trimmed the new sides to match the height best as I could tell it from the warped remnants, then added the ring the lid snaps to and heat fused it in and cut two notches*.

I cut a center hole for the neck out of the old lid then enlarged it at top and bottom to match the original. By then I had ground out the rivets that joined the metal parts of the old cover. *The cover contains two levers that protrude from the side of the yoke below the lid (thus the two notches). Those two levers move two pieces of, presumably, steel in and out of a plastic slide track that rides between the yoke windings and CRT neck as some sort of adjustment. I painted the lid and new sides Lincoln touch up paint black and assembled. The result while not perfect is a heck of a lot better than exposed yoke terminal strip and uninstalled adjustment levers. Up close you can tell it is a repair but at least it is a decent looking/working one.



While I was at it last night I also repaired a contact in the yoke. There is a box above it that contains an adjuster and a terminal for a device mounted on the blue lateral that is in series with one of the horizontal yoke leads. The terminal that device plugs into broke on me early in the resto and I was using an alligator clip to get by.The contact was basically the same as a fat pin tube socket heater contact so I robbed one from a junk socket and soldered it in on top of the original contact. The yoke is now good. I was able to do a quick roughing in of the purity adjustment last night.

Hopefully in the coming week I'll have it working right.
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Tom C.

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