[Milsurplus] Re TA -12 tx

[Mike Hanz]

pete williams wrote:

>The TA-12 (Bendix) was obviously used with a  receiver (RA-10? ?) ..
>Query.
>  How was the companion rx muted when going to transmit ? ----- there
>does not appear to be any PTT facilities with the tx or the external
>modulator/dyno. Pins 12. 13 and 16 are mic inputs  to the  dyno /mod
>but no tx/rx facilities obvious.
>

It's a bit circuitous, Pete.  The wire from microphone tip in the MS-18B 
jack box goes to pin 16 in the modulator/power supply through an MS-14B 
junction box.  Microphone sleeve runs through the same junction box and 
ends up at pin 2.  That's how it gets the PTT signal.  The set isn't as 
self contained as some other designs because you really need some kind 
of junction box to tie everything together.  See 
http://members.cox.net/aafradio/flightdeck/bendix1.htm for the piece 
parts.  Unfortunately, you also need an MT-51 control box to select CW, 
MCW, or phone - you can't do it from the TA-12 front panel.

73,
Mike