Help with Cap Type Identificaton
 

Ive taken several pics. Can anyone tell me what each type is and if it should be replaced during a restoration? The first pic is 2 ceramic disc looking ones but dark brown/maroon with yellow printing and a waxy feel to them. 2nd one no idea, Third has an orange paper wrapped one and a white one. 4th Pic is a brown plastic? 5Th has another black plastic? one and 2 small light brown plastic ones I think but these look like large resistors. Last pic has a brown one that has the form of a maroon drop but isn't maroon.

Any of these that are OK to leave?

Leave the first alone unless they are suspects after recap. Second is a bumbel bee type which is a paper capacitor molded in plastic these are as bad or worse than all paper types and should be replaced(4 and 5 are the same type with different plastics used). 3 white on is paper or some such and tends to fail. 3 brown is electrolytic and should be changed. 6 ignore unless suspect after recap.

I'm going to guess that you are fixing a Zenith color roundy based on the pics.

1st pic--Ceramic discs, just darker brown than usual.

2nd pic--Plastic molded paper, AKA "Bumble Bee" or "Black Beauty" capacitor.

3rd pic--Orange--Aluminum electrolytic
White--Ceramic encased paper or mylar film

4th pic--Plastic molded mylar.

5th pic--Black--Plastic molded paper (see #2)
Brown--unknown. Possibly resistors or inductors

6th pic--Dipped mylar film (similar to orange drop)

Ok thanks guys!

But I'm confused on #4, is it mylar or paper?

Mylars are OK to leave unless suspect after recap?

I would be suspect of #4. It may be a replacement but whilst you are replacing, it is much easier to replace it now than later. I think it is paper disguised as a mylar. But I am no expert, so I could clearly be wrong.

#4 looks to be a paper, but could be mylar. Either way, the safest thing is to replace even old mylar with new.

Daave,

In addition to potentially bad condensers, also visually check for other problems, like this apparent cold soldered joint.

This Elmenco capacitor may be a replacement, as bad soldering is rather rare on the hand wired Zeniths.

James

The only caps I would leave in a set would be the ceramic discs. All others really should be changed out for new ones. Otherwise you will be back in the set in a few months looking for that failed capacitor you did not change out.

There is a bunch of mica ones in there. As I remember reading these are as good as ceramics?

Micas are more reliable than paper, but I have found bad ones from time to time. I usually leave them alone during the first go-round and then try the TV out.

Horizontal circuits are where I have most often needed to replace micas. I'd avoid replacing micas in RF or IF circuits unless needed, as "shotgunning" them without a specific reason may force an unnecessary realignment.

Phil Nelson

As they say, "Good Catch!" Yes, it could be a cold solder joint and I would replace the cap whilst I was visiting that capacitor.

As for mica capacitors, I would not replace them unless you have a good reason to. They are usually very stable and often still good. Yes, I know that some are starting to cause problems. Important word, "some". They are 50 years old.

Replace those tubular capacitors, one at a time. Test again, do the next one. Test again. You will most likely be rewarded with a good result. Mica caps are usually very low values, not something like .01 µFD. If the markings indicate that it really is .01 µFD then it is a paper capacitor in disguise, not mica and should be replaced. Micamold comes to mind!

If you still have problems, then you may need to trouble shoot and see if a mica cap is causing a problem. Disc capacitors are in the same arena.

I know the temptation is there to replace them all and then test. Trust me, I have done it and regretted it. It is a pain to power up after each replacement. But you can stay out of trouble that way.

Exactly!

Even 20 years ago these caps were very bad. Sometimes they acted like little batteries, producing about a volt from end to end, not what you'd want in a cap...

The color bands read like a resistor, it says the number of picofarads.

http://antiqueradio.org/art/recap13.jpg

Sometimes colors fade (for instance, faded or dirty violet might be mistaken for gray or brown), so compare the value that you read with the value given in the schematic.

Phil Nelson

So there are many types of caps I see, the orange dips are popular, but is it OK to replace a ceramic coated film 1000 volt .015uf cap with a 1600 volt .015uf orange dip? Or do I have to find another ceramic tubular metalized film cap?