21CT55 #2628 restoration

[ohohyodafarted]

The original gray 30KV doorknob on my CT55 also went bad. I found a suitable 40KV doorknob on ebay. Mounting was slightly different, but was easily modified to work like the original. I also see that the discharging assembly that grounds the doorknob has been removed. I installed a low RPM cooling fan on the HV cage to keep the flyback cool.

Here is a link to the restoration pages of my CT55 on my web site.

http://antiquetvguy.com/Web%20Pages/...CA-21CT55.html

Good luck and welcome to the CT55 club!

[Zenith6S321]

Originally Posted by ohohyodafarted

The original gray 30KV doorknob on my CT55 also went bad. I found a suitable 40KV doorknob on ebay.

Bob, thanks for the ebay tip for a capacitor. Would a 2700pF 40KV work ok as a replacement for the 2500pF 30KV?

Dave

[Zenith6S321]

I've done some cleaning to the chassis. I used naval jelly (thanks bandersen) for the cleaning and to treat the rusted areas. The chassis "before" picture is above, here are some "after" pictures. Also is a picture of HV capacitors that I will replace with the 40KV 2700pF door knob capacitor to replace the mess. I have not yet figured out how to clean the HV cage, any suggestions? I compared my flyback with the two Bob shows in his restoration page: http://antiquetvguy.com/Web%20Pages/...CA-21CT55.html
I think mine is the same replacement Bob is using.

Dave

[ohohyodafarted]

Looks like the photo of the fine tuning knob in the picture (if that is what it is) is wrong. That fine tuning knob is probably for a ctc5. You need a fine tuning knob like a CT100 uses. IF has a great big hole in the center (about 1.25" dia)

RE: HV cage. If you have an electroplating shop that does tin plate, I would take it there. Zinc can also be done but it doesn't look as good as tin plate.

Otherwise a simple paint job with aluminum spray paint looks OK.

[Zenith6S321]

Originally Posted by ohohyodafarted

Looks like the photo of the fine tuning knob in the picture (if that is what it is) is wrong. That fine tuning knob is probably for a ctc5. You need a fine tuning knob like a CT100 uses. IF has a great big hole in the center (about 1.25" dia).

Yes, I have not been able to find one, so I bought this one in hopes of fabricating a stronger central part and attaching it to the outer part of this one. The channel changing knob will fit within the outer grip area of this fine tuning knob.

Dave

[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.