I didn’t see any point in reinventing the wheel, so I picked the best Ryobi adapter here and extended it. This uses the same Keystone clips and everything. You are free to put whatever 18 to 12v converter you can fit in there. Right now, I am using a cheap buck converter off Amazon, but this may change if there are noise issues. It meets my needs.
The holes in the center piece are made for brass inserts. I’ve included the fusion file if you need to make them smaller for direct threading.
73!
The author remixed this model.
I added a hood to conceal the buck converter and hold the radio at a good angle for reading the display and operating the controls. I also modified the ’tower’ so it can print without support and hold a threaded insert on each end.