My computer skills aren't stellar so I apologize if this should be a new topic rather than a reply.? I am having difficulty understanding how to connect an external electret condenser mic to my completed QMX+.? I understand that the ring in the jack is connected to both the mic input and through a 2.2K resistor to a 3.3V supply.? It would seem to be as simple as connecting both the mic connection from the mic and the connection to supply power to the mic to the ring on the plug.? My first attempt was with no connection to the supply power to the mic and I found that if I shouted loudly enough I could indeed generate a small RF output, I even made a very difficult contact!? Arranging to connect the power connection to the ring I find that the PTT is engaged when that connection is made.? The mic I am working with is from my junk bin and I am almost certain that it at one time functioned as expected with a TS-940, 850, or 950 radio.? I am preparing to connect an external DC supply to the mic, no power to the QMX+ other than back through the mic itself.? Alternative is to purchase another mic of known specifications bit I would have the same wiring question.? Any direction from those more knowledgeable would be greatly appreciated!? A wonderful project and I am expecting the final card played will yield a wonderful radio.? Thanks to Hans and all those participating!
OldEngineer