I had a look at the link you provided, Doug.
![[Image: pinout_1062355983_image.png]](https://pinoutguide.com/images/upload/pinout_1062355983_image.png)
The diagram doesn't represent the configuration of the plugs on the Aliexpress headset - My experience with such accessories is not extensive, but I've not come across a case where the mic is on the 3.5 plug and the speaker on the 2.5, so it looks to me that the diagram is wrong. Either way, the existing headset I have has the mic on 2.5 and the speakers on 3.5.
So too does a 20-year-old speaker mic that I have. It came with some other plug that I don't remember, but I modified it to a 2-pin 2.5 on the mic and a 2-pin 3.5 on the speaker. It works fine in the TX667 I have in front of me.
Opening up the case, it looks like the PTT just makes the connection to the electret, but there's what looks to be a diode and perhaps a resistor across the leads of the electret.
The diagram doesn't represent the configuration of the plugs on the Aliexpress headset - My experience with such accessories is not extensive, but I've not come across a case where the mic is on the 3.5 plug and the speaker on the 2.5, so it looks to me that the diagram is wrong. Either way, the existing headset I have has the mic on 2.5 and the speakers on 3.5.
So too does a 20-year-old speaker mic that I have. It came with some other plug that I don't remember, but I modified it to a 2-pin 2.5 on the mic and a 2-pin 3.5 on the speaker. It works fine in the TX667 I have in front of me.
Opening up the case, it looks like the PTT just makes the connection to the electret, but there's what looks to be a diode and perhaps a resistor across the leads of the electret.