21CT55 #2628 restoration

[miniman82]

Originally Posted by Zenith6S321

I think mine is the same replacement Bob is using.

Mine also looks like his replacement, but I'm unsure if it's just that the wax melted off Bob's donut or there actually was a different one. I always figured it was original.

[Zenith6S321]

Originally Posted by miniman82

Mine also looks like his replacement, but I'm unsure if it's just that the wax melted off Bob's donut or there actually was a different one. I always figured it was original.

I was judging from the wider looking HV donut on his replacement flyback and its brightly colored lead insulators. Or maybe the old one discolored its leads when it died. Here is a shot of some numbers on one end of my flyback.

[Zenith6S321]

All of the original chassis mount caps tested open, leaky, or way off value. The "modern" (1977-ish) replacements that I had tacked in, way back then, all reformed nicely. I am not going to trust them, so I have started re-stuffing the old electrolytic caps with 105C caps. Here are some pictures of a few of them being re-stuffed. I have all but one of the chassis mount cans re-stuffed and I have started wiring them in. The 2700 pF door knob capacitor arrived and I think it will fit in the HV cage well.

[ohohyodafarted]

Nice job on the re-stuffing!

I also use the same method, removing the can from the chassis and pealing back the rolled edge of the can to remove the tab ring. I much prefer this method over the method that cuts through the aluminum can above the base of the can. It's a lot more work using this method, but this method retains the original can in one piece, pretty much un-molested. And when re-installed on the chassis, it is hard to detect that it was re-stuffed.

[Zenith6S321]

On my first attempts I was using a small pair of wire cutters to pry the edge up. It was pretty easy that way, but left ugly marks on the outside of the wider ring at the bottom of the can. With the right small jewelers flat blade screw driver I can force up the edge and then wedge it in, applying pressure along the circumference and then pry up a very short bit at a time. It gives a nice result but is tiring on the hands.

Dave

[ohohyodafarted]

Originally Posted by Zenith6S321

On my first attempts I was using a small pair of wire cutters to pry the edge up. It was pretty easy that way, but left ugly marks on the outside of the wider ring at the bottom of the can. With the right small jewelers flat blade screw driver I can force up the edge and then wedge it in, applying pressure along the circumference and then pry up a very short bit at a time. It gives a nice result but is tiring on the hands.

Dave

I use an old Stanley scratch awl with a wooden handle. I have it ground and curved the tip in such a way that I can work it under the rolled edge and use it to "roll" the edge open once I have it started. Then after I have the tab ring removed. I use a piece of water pipe just the right size, clamped in a vise, as a curved anvil. I take a small ball peen hammer to flatten the unrolled aluminum edge against the pipe anvil. You need to be careful with the awl so you don't slip and run the point into your hand when working the rolled edge open.

[Zenith6S321]

Re-stuffed the last electrolytic after the parts came in. This one is the 1000uF 3V non-polarized cap. Here are some pictures of before, cover un-crimped, the parts, back together, and back in the set. I did this for the other little electrolytics except for three that I did not have the original caps to re-stuff. I wet the paper cover before I uncrimp the end to try to keep the paper from crumbling.