The T-17 microphone is used on a wide range of WWII radio equipment. It comes in many different flavors, some are bakelite, others are metal body as is the T-17-E shown in the picture below.
However, one thing they all seem to have in common is a bad or marginal carbon cartridge. They are supposed to be very low resistance, but most will measure 1K or more. Good replacements just about impossible to find.
Some of the WWII equipment has marginal modulation with a good mike , such as the SCR-274 BC-456, but a poor mike will reduce your emissions to not much more than a carrier!
In order to make the use of the equipment easier ( not needing to talk very loud in to the mike) , I have designed a circuit using the ubiquitous electret mike that is more sensitive than the original cartridge output.
Here's a picture of the prototype:
I have now produced a commercial version for 24-28V radios that use the T-17 . see below:
It fits inside the mike body just fine .
You don't have to worry about polarity, because the circuit figures that out for you. just remove the old cartridge , solder this PCB in and you're done!
For more information, or to purchase, contact me via the "contact us" form on the menu.