I've seen many Chinese HTs (Baofeng, Puxing, Wouxun, QuanSheng etc.) using the so-called "Kenwood connector", which has a 2.5 mm TRS connector and a 3.5 mm TRS connector. It looks something like this:
I've seen it used for serial ports, speakers, microphones, PTT devices and similar.
My question is: What's the exact pinout of this connector?