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Identify decoupling capacitors?

I'm trying to identify some decoupling capacitors, probably ceramic. They're orangish red, about 8 x 6 x 1mm axial leaded. They are labelled on the top, that is the 8 x 1mm curved face away from the leads:-

104 YME

To the left of this is what I take to be the trade mark which is a narrow slanted V which is as large as the two lines of lettering above. The left arm of the V is about 5 degrees clockwise from vertical while the right arm is about 10 degrees so the whole V points down to the left.

I assume 104 means 100nF as it usually does. What does YME mean?

I'm asking because these caps were provided for a fairly exacting operation, namely decoupling photomultiplier dynodes in cryogenic conditions. They'll be run at about 200V and , er, -190C. They look awfully small for 100nF/300V and I have my suspicions about their temperature coefficients.

Reply to
John McMillan
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At 8x6x1mm, they are very unusually shaped for axial lead capacitors..

Vitramon (now Vishay Vitramon) used to make some some very nice capacitors, both ceramic and porcelain, for higher voltage or more exacting situations. They were not notably small. Their trademark was Vy, sloped roughly as you describe.

Vishay offers axial/radial leaded monolithic ceramic parts at 200 and

500V, up to 47nF, in the X7R dielectric class. These will display a negative voltage coefficient. NPO dielectric parts are going to be hard to come by above 10nF. You might try Temex Ceramics.

YME doesn't mean anything in the EIA, ANSI or MIL codes.

For this application, you will have to qualify your own parts anyways, as few are characterized below -55C. This is time consuming and should be performed on known parts that do what you intend them to do over their originally-designed range.

RL

Reply to
legg

Whoops, I meant radial.

I thought of them but couldn't find an old trademark. All the stuff on the web has their current trademark. Thanks for the confirmation.

I know. I guess its time to do some proper tests.

Reply to
John McMillan

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