Anybody ID these caps for me?

Silver Blues · #1 11-05-2012, 03:36 PM

Hey guys and gals,

I was just rifling (for the what, third time) through my available stash of defunct electronics in search of capacitors suitable for use as tone caps. I have a pretty big stash going now, which is OK by me, variety is good.

But I digress. My real question is about three pairs of very special caps I found during my excursion. I have and am missing information about all three of them, and I was wondering if any TB electronics gurus could help me out.

1 - I know that these are 0.047uF, however I don't know brand or material. They look like PIOs to me, but I don't really know.

2 - I don't know anything at all about these, no value, no material, no brand, no polarity...

I'm hoping someone else has seen them.

Third one in a new post...

--Silvie

Silver Blues · #2 11-05-2012, 03:38 PM

3 - I know these are 0.03uF, but no material or brand. They look sturdy, have to say.

So yeah, can anybody help me out plzzz???

--Silvie

line6man · #3 11-05-2012, 03:56 PM

First one is paper in oil. Second looks like a Ceramic capacitor, though they tend to be flatter, whereas yours are fairly fat and round. Third looks like a Polymer (OsCon?) or Aluminum Electrolytic.

Silver Blues · #4 11-05-2012, 04:01 PM

Quote:

Originally Posted by line6man

Second looks like a Ceramic capacitor, though they tend to be flatter, whereas yours are fairly fat and round. Third looks like a Polymer (OsCon?) or Aluminum Electrolytic.

I thought maybe they were polyester film like the myriad of green "chiclet" caps I have; you're right, all my ceramics are disc caps which these don't seem to be. Do you by any chance know what the value might be on these? Stupid no markings.

Yeah, it could be either... if it is an electrolytic does that make it immediately unfit for instrument use like all the other electrolytic ones?

Thanks.

--Silvie

megafiddle · #5 11-05-2012, 04:02 PM

The color dots on #2 look like red and violet, so I would guess a "27" for the digit part
of the value.

Can you read the 3rd color?

Caps that small are non electrolytic and have no polarity.
The band at one end of cap #1 indicates outside foil. That terminal was important in RF circuits,
where it could be connected to a grounded point in the circuit and the outside foil would shield the rest of the cap.

megafiddle · #6 11-05-2012, 04:08 PM

I should have said that caps that small in value are non electrolytic.

If #3 is an electrolytic, it's value will be way too high for use as a tone cap (if that's what you are using them for).

line6man · #7 11-05-2012, 04:09 PM

Quote:

Originally Posted by Silver Blues

I thought maybe they were polyester film like the myriad of green "chiclet" caps I have; you're right, all my ceramics are disc caps which these don't seem to be. Do you by any chance know what the value might be on these? Stupid no markings.

Yeah, it could be either... if it is an electrolytic does that make it immediately unfit for instrument use like all the other electrolytic ones?

Thanks.

--Silvie

Don't use Aluminum Electrolytics and Tantalums and such for tone controls. Any other non-polarized cap works fine, however. Makes no difference in that particular application.

Silver Blues · #8 11-05-2012, 04:28 PM

Quote:

Originally Posted by megafiddle

The color dots on #2 look like red and violet, so I would guess a "27" for the digit part
of the value.

Can you read the 3rd color?

Yup, two reds, a violet and the third is gold.

Quote:

Originally Posted by megafiddle

If #3 is an electrolytic, it's value will be way too high for use as a tone cap (if that's what you are using them for).

0.03uF is too high for a tone cap?

I don't think so.

Quote:

Originally Posted by line6man

Don't use Aluminum Electrolytics and Tantalums and such for tone controls. Any other non-polarized cap works fine, however. Makes no difference in that particular application.

Okay, yeah that's what I thought.

--Silvie

line6man · #9 11-05-2012, 04:38 PM

Red is 2, purple is 7, gold is *10^-1.

megafiddle · #10 11-05-2012, 04:39 PM

No, .03 uF is way too low for an electrolytic.

If it is .03uF, it is not an electrolytic.
If it is an electrolytic, it is not .03 uF, but would be much higher.

Hope that makes sense.

Silver Blues · #11 11-05-2012, 04:39 PM

Quote:

Originally Posted by line6man

0.27nF, I would imagine.
Red is 2, purple is 7, gold is *10^-1.

Thanks. See, that's too small. Oh well.

--Silvie

Silver Blues · #12 11-05-2012, 04:40 PM

Quote:

Originally Posted by megafiddle

No, .03 uF is way too low for an electrolytic.

If it is .03uF, it is not an electrolytic.
If it is an electrolytic, it is not .03 uF.

Hope that makes sense.

It does, don't worry

It has to be 0.03uF, because it's code is 303. So it's not electrolytic then... good.

--Silvie

megafiddle · #13 11-05-2012, 04:48 PM

Reading from one side to another, is it red, violet, red, gold?
That might possibly be 2700 pF (.0027 uF) 5 percent tolerance.

Silver Blues · #14 11-05-2012, 04:49 PM

Quote:

Originally Posted by megafiddle

Reading from one side to another, is it red, violet, red, gold?
That might possibly be 2700 pF (.0027 uF) 5 percent tolerance.

Exactly right. Either way it's still too small...

--Silvie

Silver Blues · #15 11-06-2012, 01:13 PM

Okay well thanks guys, you were all a great help, I think I've got all the info I needed. Amazing what you find on old circuit boards.

--Silvie

I didn't know my camera did such great macros. Those are nice clear pictures.

SGD Lutherie · #16 11-06-2012, 08:57 PM

#2 looks like tantalum caps. I doubt there's any oil in the first ones, they just look like mylar caps.

Pick caps based on the value of the cap. The type of cap wont matter for a tone control and they will all sound the same.

Silver Blues · #17 11-07-2012, 04:27 AM

Quote:

Originally Posted by SGD Lutherie

Pick caps based on the value of the cap. The type of cap wont matter for a tone control and they will all sound the same.

IK, I was just curious. If it did matter, I would spend a week trying out all my caps in each new bass

--Silvie

Silver Blues · #18 11-29-2012, 03:15 PM

Question answered, taking down the attachments. Thanks all.

--Silvie

two fingers · #19 11-29-2012, 10:58 PM

How to measure a cap without a cap meter.
http://www.youtube.com/watch?v=ttzqpTWDDAc

Seems pretty straightforward to me. A lot of caps are in the uF range so odds are it will work.

Silver Blues · #20 11-30-2012, 02:28 PM

Quote:

Originally Posted by two fingers

How to measure a cap without a cap meter.
http://www.youtube.com/watch?v=ttzqpTWDDAc

Seems pretty straightforward to me. A lot of caps are in the uF range so odds are it will work.

That's odd, kinda cool. I don't run into situations like that often though, 9/10 times I know the value but not the material type, polarity etc.

--Silvie