This is from the schematic to a Tytera MD-380 radio.
Shown here is the mic preamp. I was curious to see what this looked like as transit audio quality and level are said to vary a lot from one radio to the next.
Unless I’m missing something – there’s no way for DC voltage to get in there and let those transistors do their job.
Annotated to show where capacitors block DC:
I’m considering buying one to play with but. .. uh… only somewhere with a good return/exchange policy.