Motorola DP2600 Remote PTT/MIC/SPK

We are setting up a remote PTT, remote speaker and remote mic for use with a Motorola DP2600.
We have the pinout for the 8 pin connector but we are unsure about the PTT circuit. We have stripped and tested an RSM and it appears to be pins 1 and 4 that are the PTT. We have measured 7K ohms when not pressed and 4.3K ohms when pressed across pins 1 and 4.
Are we on the correct path? Can anyone assist us by sharing a diagram for the correct setup of the PTT circuit for the DP2600? I have included a diagram of the side connector

It does look like you’re on the right path. But a suggestion is almost always to buy a cheap $10 earpiece to cut up and use a multi-meter. This is because there might be certain nuances like a resistor in the plug that the socket requires in order to allow the PTT to be activated for example.

Note that the DP2600 is the EMEA version of the XPR3500. So you can google both radios when doing your research.

Good luck.

Great advice, thanks

I had a TL in 5th SFG. He went on to do other things for the USG. Is it you??