[MRCA] GRC-109/T-784 "Voice" Design Challenge

[ac2eu at yahoo.com]

 This radio was never intended for voice communication , probably because the messages had to be encoded.It's part of the device history. Why would you want mod it? The GRC109 is rather rare, isn't it?There are lots of other voice mode radios out there to choose from if you don't do CW.
    On Thursday, October 16, 2025 at 01:03:44 PM EDT, MilComm Guy <m38inmaine at gmail.com> wrote:  
 
 I picked up a GRC-109 set at the Nearfest show this month, as I was walking back to my truck with it Charlie mentioned how he had thought about a voice mode modification and that it may not be too involved.  So I thought I would toss out a design challenge here hoping the mil radio community here will participate and come up with your design to add a voice mode circuit for the T-784.
A few features necessary would be:1 Fit in the available space inside2 Non-invasive ie easily removable back to original configuration3 Compatible with period correct microphone, T-17 or M-80 wired to a PJ-068 plug.
My contribution would be to make a bushing for the existing desiccant tube hole to accept the jack for the PJ-068 plug, this way there are no extra holes.  
I know very little about radio circuits, I'm a nuts and bolts MV restoration guy and have to rely on the seasoned experts here, of which there are many.   If you would like to submit a design please do so here on the reflector and start a discussion on it.  What's in it for you ?, I will gladly pay for the parts and on your end satisfaction of a job well done.  I will also have a nice data plate made up with all the call signs of the design entries, no call no problem initials will work.
A copy of the manual can be found here:https://www.cryptomuseum.com/spy/rs1/files/TM_11-5820-474-14_19620518.pdf
I would also like to thank all the MRCA gang for all your help, without you my mil radio hobby would not be possible, the knowledge and willingness to help is greatly appreciated.



ThanksMarkK1HF______________________________________________________________
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