Recapping a CTC-15 clone

[blue_lateral]

Over the past few days I have been going through the Silvertone chassis looking for drifted resistors and so on. This set has pretty high hours, so I expected it to be pretty cooked. As it turns out, it's not that bad. Ive only found about 5 resistors so far that are out of spec, and 2 of those were stuffed with the wrong value in the first place (apparently). Now I guess I need to do something about caps.

Most of the small caps in this set are orange drops, dark purple things that look like orange drops, and ceramic disks. I was planning on leaving all of that alone, unless there is some specific problem. What do you guys think?

There are a few caps in here however, that I dont know what they are. I think they might be paper. There are about 5 of these tubular ones, that look like paper caps, but the "paper" tubes feel like they are ceramic! Are these any good?

[blue_lateral]

Heres a plastic tubular thing that looks like it might be like a black beauty. Is it paper?

[blue_lateral]

And a blue one thats shaped like an orange drop, but made of injection molded blue plastic. Fisher Price?

[blue_lateral]

And that leaves the electrolytics. I was just going to replace them all on general principles, but after looking under the chassis, there just doesnt even seem to be room for the voltage doubler caps, let alone the others, and the terminal strips I would have to install. This set has 2 4-section cans, 1 2-section can and 1 1-section can. 11 caps! There is just no room. I am thinking of just leaving it alone and checking the dc voltages and ripple. I guess I could make a board and mount it above the chassis. This was a working set. What do you guys think?

[andy]

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[jstout66]

IMHO, I think concerning the caps you should leave it alone. By the mid 60's sets used the "modern" type caps and I think there is a chance to cause unwanted problems by changing them. Hell.... I have a 1957 RCA B&W console I've had for 15 years and use heavily and it should probably be re-capped, but I've had NO problems. So if ain't broke why fix it?

[bgadow]

I would agree, my experience has been good with the old caps. I replaced them on a Zenith 25MC30 because some of the cans felt a little warm, but I saw no difference in perfomance. One of the cans on my CTC-15 was replaced to correct an ugly old repair. One of the cans on my CTC-11 had gone bad, blown the breaker, spilled its guts...but no problems with the others. Those Elmenco's are paper but most I've left alone. I would wait & see how the set runs as is.

[peverett]

I have also had good luck with post-1960 capacitors. It seems that capacitor manufacturing matured at about this time.

On the other hand, I completely re-capped an 1953 Hoffman. It seemed that every black beauty in the set had a crack down the side.

[Jonathan]

I think all three pictures of caps you've posted are paper, but I could be wrong. All of them have the band at one end indicating it's the foil end of the capacitor. The big blue one even says "Outer Foil". If I was restoring it, I would replace all of those and hope for the best, but just like these guys said; If it ain't broke, don't fix it.

Jonathan

[RetroHacker]

Some of those plastic looking caps are really just paper caps with molded plastic around them. The "black beauties" were this way. Some, like these slightly more modern ones, are a bit more reliable, but I've seen several leaky ones. If you're recapping the set because it's not working properly, then yeah, I'd probably just go ahead and replace 'em all, but if all is well, then you should probably just leave them alone... but - remember - replacing capacitors with the same value shouldn't really change anything, provided that the original was good at the time you replaced it. A .01 cap is a .01 cap is a .01 cap - but if you replace a leaky .01 cap with a good one, then there will be a difference. I'd say spot check a few with a meter, try to see if any are obviously leaky - if so, replace 'em. If everything works and the caps check out, leave it alone. Check your voltages, and make sure things are within spec, if you've got way-off voltages on some of your tubes, start suspecting the caps in that area. Just because the set _works_, doesn't mean that everything is perfect. But, then again, this is the obsessiveness in me speaking. If it ain't broke, don't fix it. Watch it until it breaks, then fix it .

-Ian

[Chad Hauris]

Personally I have not had too much trouble with caps in 60's TV's but have had more trouble with caps in public address amps and stereo amps of the same time period. Most trouble with caps in 60's tv's has been bad electrolytics.

However when I have something on the bench from the 60's or before I like to replace any old paper or electrolytic caps and selenium or old silicon diodes, especially if it is a unit for a customer. Even if the unit works now with the old parts, replacing these common failure items helps ensure the unit will stand up for long service into the future...these old components like electrolytics or paper caps continue to degrade as time goes on.

[Charlie]

In most cases, I have replaced the ceramic tubular and plastic tubular. Sometimes the ceramic tubulars might get left in there if there are no apparent problems.

As far as 60's electrolytics, I generally replace them with the thought I will likely watch the set on a somewhat regular basis. As you pointed out, there isn't much room under there and it's somewhat of a pain to find a place for them.

I did, however, leave all of the original lytics in the 15 I put together last year. I left them in there because I noticed they all ran cool. If any run warm, they should likely be changed out. For the most part, my 15 plays well. However, it usually needs to warm up for 5 minutes for the color to come in and the brightness to come down to a normal level. I might change some of them soon to attempt to correct this if I can't find any other apparent problems.

Also, if you see any oozing black stuff coming out where the connections are, you should likely replace them.