[ARC5] T-17 Microphone

[Mark K3MSB]

Hi Guys

I successfully used my BC-456 ( with the dynamotor) for the first time this
weekend in my SCR-274N system!  I’ll get a post out on that saga hopefully
later on today.  Alas, I was not able to test AM as I found (and had
suspected) that my NIB T-17 mic wasn’t ready for use.

The insulation on the pigtails coming out of the mic cable pretty much
crumbled when touched, so that pretty much told me it was not a good idea
to try and attach the mic plug and actually use it.

Last night I completely disassembled the T-17.  Just moving the wires
inside the mic made the insulation crumble to dust, but I was successful in
learning what had to be replaced and making a wiring diagram.   Took lots
of pictures too.

First, can the carbon mic element be salvaged?  I’ve heard that drying it
in the sun or oven and then shaking it will loosen up the carbon.  Is there
a recommend mic element replacement?  I’ve read that an telephone
mouthpiece mic element will work, but I no longer have a “vintage” phone
handset…..

The matching transformer looks to be in good shape;  the insulation on
those wires looks to be good (not crumbly), but I may still put a small
piece of heat shrink over them.

The capacitor – I assume that’s what’s on the piece of phenolic?  What is
the value supposed to be?

Mic cord replacement – recommendations?  The cord is about 1/4 inch in
diameter, three conductor.   Places like Rapco sell mic cable by the foot
and their 3 conductor cable just under ¼ inch diameter…..   I doubt this is
a critical matter, but thought I’d ask (since I’m asking questions…..)   :-)

Thanks!

Mark K3MSB

Sent from my Android phone