[ARC5] T-30 throat microphone

[Mike Hanz]

On 1/11/2015 7:38 PM, Robert Eleazer wrote:
> Back in the mid-70's I got a T-30, plugged it into the stock PTT switch that matched it and gave it to a friend to try out in his airplane.  He got signal reports back that his voice was garbled.  Aside from that, he said he just knew that if the airplane crashed he would be trapped by that strap around his neck.

In addition to the warning from the Bell Labs document, the "Graphic Survey Of Radio And Radar Equipment Used By The Army Air Forces (Vol 2.)" has this on the T-30:  "The intelligibility of its output varies widely according to the shape of the throat, voice, and accent of the individual speaker."  I can't imagine the USAAF running around testing every flyer for those characteristics...  :-)   

Besides the shift to oxygen mask mics, it's no wonder they became disused toward the end of the war.

> What kind of adapter was employed for the tests?

Not sure, but I think it was simply an adapter cable from a male PL-291 
to whatever the interphone system used.  They had a modern set of 
aircraft radios in the plane.

73,
Mike