Antonio Vernucci wrote:

1) I have been told that carbon microphones can be revitalized by leaving them
in an oven for an hour or so at a temperature of about 180 F. Did anyone try to
do that? It would be easier to put the entire microphone in the oven rather than
just the capsule, but I am not sure on whether this could cause damages to the
non-metallic parts

I have done this before, although not to a T-17. The idea here is to bake
all the moisture out of it, because the moisture causes the carbon granules
to cake up and stick together. It took me a lot longer than an hour or so.

180'F isn't really very hot.

2) I would like to test the microphone by measuring the output voltage with an
oscilloscope while talking. Does anyone have an idea on how much (peak) voltage
I should see on the scope when powering the microphone with 12 V, through a
resistor of known value?

I do not. BUT, I would suggest first of all measuring the static resistance
of the microphone and comparing that with the resistance of a known-good
microphone.

I might also try using a telephone transmitter element (in the US we have
lots of Western Electric T-1 transmitters everywhere) and comparing that
with the test microphone in measured sensitivity.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."