Vintage 3 Terminal Capacitor??

[Beatswork]

Just when I was feeling reasonably confident about recapping an amp I came across this capacitor. Two negative leads, one positive, and no continuity between the two negative leads. No luck on codes and I cannot even find a reference to vintage 3 terminal caps in tube application!

Any ideas?

An externally hosted image should be here but it was not working when we last tested it.

 

[BinaryMike]

Should be pretty easy to see how it's connected into the circuit.

 

[Beatswork]

Should be pretty easy to see how it's connected into the circuit.

Matching caps within tolerance and replacing them is about the limit of my "expertise" at the moment I'm afraid. This threw me completely as I can find reference to a 3 terminal cap for motor start applications and modern surface mount caps but absolutely nothing relevant to vintage tube application.

 

[Tubelab_com]

If both negative leads were connected together by a trace on the PC board, or one has no connection at all, then it's just an ordinary two terminal cap with an extra wire to help hold it in the PC board. Early vintage brown phenolic PC boards were notoriously bad for delamination or traces peeling off.

 

[Beatswork]

If both negative leads were connected together by a trace on the PC board, or one has no connection at all, then it's just an ordinary two terminal cap with an extra wire to help hold it in the PC board. Early vintage brown phenolic PC boards were notoriously bad for delamination or traces peeling off.

Aha! It's the latter - just soldered to board but no trace. Thank you for the explanation as this was driving me nuts!