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Simple . It works with a DC bias and resistance variation of carbon granules packed in a mic? convey the speech content.

?Only diffiernce is that the bandwidth would be much less as against electret or dynamic mics.

regards

sarma

?vu3zmv

Regards
MVS Sarma
?

On Mon, Apr 23, 2018 at 11:28 PM, Arv Evans <arvid.evans@...> wrote:

Lee

It will be interesting to see, and hear, how that T-32 carbon button microphone
works with the BITX.? It may need some attenuation because carbon microphones

usually output a fairly high level signal.? who knows...we could be seeing a new

trend of using carbon microphones for their inherent frequency limiting and high

output.?

Arv? K7HKL
_._

On Mon, Apr 23, 2018 at 10:32 AM, Lee <mr.olson@...> wrote:

The microphone is a Model T-32 made by Kellogg Company for military communications.? It was sometimes used with the English T-1154 transmitter in WW2 Lancaster bombers.? Yes, they were used in many places after the war and one popular use was on a PA system in railroad yards.? Since I need 4 wires I am using a Cobra/Midland CB style 4 pin plug and jack with the locking ring.