The connector exists out of a combined 2,5- and 3,5 mm jack. The 2,5mm one is used as ground and for an external speaker, the 3,5mm one powers the PTT switch and microphone.
2,5mm jack connector
Pin | Function |
---|---|
1 (tip) | External speaker signal |
2 (ring) | GND |
3 (sleeve) | GND |
3,5mm jack connector
Pin | Function |
---|---|
1 (tip) | Not connected |
2 (ring) | Microphone (should be AC coupled) |
3 (sleeve) | PTT switch (pulled low to GND when pressed, otherwise floating) |
1 ------------------ /| 2,5mm jack | | SPEAKER 2 ---+---+--------+- \| | | | 3 --- / | / ---| | | | __ 3 ------- --/ | 3,5mm jack ( | MICROPHONE 2 --------||---------\__| + 10µF capacitor 3