I'm repairing some vintage electronics, and there are a handful of cracked ceramic disc capacitors that need replacement. They're mostly for decoupling, but I want to make sure I'm replacing with equivalent or better spec. (I'm also not trying to "upgrade" much to super-modern parts even though I'm sure I could.)
I'm finding the markings inconsistent with what I'm looking at for replacement options, and hoping someone can help me clarify. Here are examples of capacitors I need to replace:
I get that these are 0.1 μF and 0.47 μF caps, 50 V and 12 V respectively, and that the letter codes of
Y5U as interpreted via here indicate temperature range and change over range. The 0.47 μF cap has the Z suffix indicating a wide +80/-10% tolerance, I believe, and that is a distinct spec from anything in the three-character code.
Most disc caps I've found as replacements simply don't have the three-letter codes, so I'm not sure how to match them up. I also have found modern ones with and without a capacitance tolerance suffix, e.g.
Here are some candidate replacements, for example:
None seem an exact match, but I can't tell if they are appropriate.
My questions are:
- What is the implied capacitance tolerance if none is noted? (As in the orginal 0.1 μF cap and the third replacement example)
- What is the implied three-character code if none is noted? (As in the latter two replacement examples)
- For use as TTL circuit decoupling caps in a piece of computer equipment that will likely get warm but never frigid or fiery, how relevant are the tolerance and temperature ratings?
Thanks for any insight.