Some of the Mid-Island Team members of the IslandHF Radio Association, have been working with low cost QRP radios and home brew wire antenna and associated electrics, including end-fed transformers, dipole baluns and cable chokes, 18650 battery cells and 3D Printing.
Here is a project that was presented by DL2MAN Manuel of TruSDX fame. He demonstrated adding a low cost mic/speaker to the TruSDX, including how to rewire the mic input. Youtube Video Instructions
Using the Retevis Amplified Speaker/Mic as the donor mic, a couple of solderable 3.5″ audio plugs and a 3D Print file (also provided by DL2MAN), along with the very well documented pin-out in the manual: TruSDX Manual
Here’s another related project. Adding a 12v battery pack to the TruSDX. Another project provided by DL2MAN, but I used slightly oversized battery holders for my 18650 cells, so it was a little bit of a squeeze. Works great. One cable for charging the pack and the other to feed the Radio. Again, the 3D models for Printing are downloadable, a little bit of clean up with a file and the box slides on and off the Radio back plate. The internal cell pack slides out of that housing as well …