Adapting a two pin headset or speaker microphone for the one pin Radioddity GD-73
d. bodnar  7-28-2020

I recently purchased a Radioddity GD-73 DMR handheld, mainly because of its small size.  One of the things that had to be done to make it so small was to make the earphone/microphone jack a single 4 conductor pin rather than the dual pin that is used on most other DMR hand helds.

This sketch shows the wiring that has to be done to the speaker/mic cable.

I chose an appropriate 3.5mm plug from Amazon - make sure you get a plug that has four contacts on the plug like this one

The connections that must be made are shown here...

... and here

You may be wondering why I chose to do the wiring onto the two pin plug rather than cutting it off and soldering its wires directly to the one pin plug.  My experience with the wire inside of these cables makes me think that the wire is likely to be thin, enameled, braided wire.  This type of wire is a pain to work with and I chose the simpler, albeit less attractive alternative method!

Before starting make sure to tin the new plug and pins on the two pin plug as shown here

Here the new plug has been soldered,

and here it is inserted into the radio.  Make sure you check for shorts when the cover is screwed onto the plug.

Here is the adapter wired up.

All that remains is to cover up the connections (with tape or heat shrink tubing) and test the headset.

Below are the direct wiring notes