Restoring CT-100 #B1111566

[Steve K]

Hi Chris:

It looks like a lot of those caps have already been replaced (other than the electrolytics). I would go and replace all the peaking coils and take Nick up on his offer. Some of the ones from the 55 may be different, I don't remember. I have restored 6 CT-100s, you'd think by now that I would have the parts memorized! It is a fun set to work on.

Steve

[Phil Nelson]

Originally Posted by Steve K

Hi Chris:

It looks like a lot of those caps have already been replaced (other than the electrolytics).

If those mylar "maroon drop" caps were installed in the 1980s, I'd leave 'em alone for now. All original electrolytics must go, of course.

When I got my CT-100, I knew that the previous owner had recapped it. He passed away a couple of days after I picked up the TV, so that's about all I knew. It took some detective work to figure out what else had been done, and what work remained.

In the parts bins that I inherited from him, I noticed drawers and drawers of little inductors, which initially struck me as odd. I eventually figured out that he had replaced the peaking coils, as well as many resistors and even some cabling. Since he had never gotten the set into playable condition, none of this work had really been "battle tested." I spent loads of time nervously tracing connections and triple-checking for mistakes. All of his work was correct, and very neatly done, which was a great relief. Len deserves a lot of the credit for bringing this TV back to life.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[ohohyodafarted]

Chris,

The white peaking coils are the ones that usually are the bad ones. The brown ones are usually OK. You can easily tell if the coil is bad by lifting one lead and measuring the DC resistance which is on the Sams parts list.

[Pete Deksnis]

Originally Posted by ohohyodafarted

Chris,

The white peaking coils are the ones that usually are the bad ones. The brown ones are usually OK.

Amen! That's a solid fact. Chris, you've received a number of suggestions so far. Let me add mine: I see only one white inductor on your chassis; it's a little distance from between the red and blue boards (they contain the circuitry for the matrix and R, B, and G amps). Check the continuity of that white inductor. If it's open replace it; if not, leave it. Replace it when it opens, if it opens.

My reason: I personally would rather have the original RCA part in the chassis with its factory-defined specifications. I can see the 6.7-uH coil in the Q filter was replaced sometime in the past in your chassis. On my site I had a page describing how the function of that stage deteriorated when the factory part was replaced with the NOS 1954-RCA-specified replacement part listed in SAMS.

Also, in my estimation, those three video boards have been restored; I would not repopulate them unless you found out-of-spec components.

Enjoy your CT-100.

Pete