1
\$\begingroup\$

I'm trying to reverse engineer an amplifier, and there's two components that I cannot identify. For context, it was made in 1973 so it's all quite vintage.

I think the first one might be some kind of fuse? There's two on the board, one between Vcc and GND, and one between the output and GND via a 10 ohm resistor. It's marked with the text 82/250, 250V maybe, with some kind of rating?

Thing

The other component is some kind of blobby thing that might be a capacitor or a coil? But if it's cap, there should be some kind of value marking, so I would expect more bands or some text?

Blob

EDIT: some more blob pictures, one from the other side, one from the top:

Blob

Blob

\$\endgroup\$
14
  • 2
    \$\begingroup\$ 82nF @ 250V mylar cap? The second item might be a PTC - thermistor. The Japanese were partial to using these. Most of that old stuff you can get schematics for on the web. \$\endgroup\$
    – Kartman
    Jan 15, 2022 at 11:22
  • 2
    \$\begingroup\$ If the first component is connected between Vcc and ground, then it is certainly not a fuse : a fuse is basicaly a wire (or a very small resistor), so if yoy put a fuse between VCC and ground, you make a short circuit, so the fuse will blow imediatly. So there is no point of putting a fuse between VCC and ground, as it will be gone at once (excepted maybe as a strange way to detect if the device was ever used or not) \$\endgroup\$
    – Sandro
    Jan 15, 2022 at 11:26
  • 2
    \$\begingroup\$ First one could be a polyphenylene cap. In that case it's most probably 82 picoFarad rather than a nano or micro farad. \$\endgroup\$ Jan 15, 2022 at 12:19
  • \$\begingroup\$ Oh wow bit of a derp moment on the fuse. So yeah let's go for a cap :') much better idea. \$\endgroup\$
    – Michel
    Jan 15, 2022 at 12:26
  • \$\begingroup\$ Can you get a photo of the second one from the opposite side? \$\endgroup\$
    – winny
    Jan 15, 2022 at 12:28

1 Answer 1

0
\$\begingroup\$

Second items looks to be a (Philips) Vishay PTC thermistor like this one but not necessarily this value: https://uk.farnell.com/vishay/ptccl13h321hbe/thermistor-ptc-8r4-20-radial/dp/1187084

\$\endgroup\$
1
  • \$\begingroup\$ I added more pictures, in particular look at the one from the top. Seems like it's way too thick for a PTC thermistor? Usually those are relatively thin? \$\endgroup\$
    – Michel
    Jan 15, 2022 at 12:57

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.