My venerable amateur radio HT APRS-voice interfaces have recently begun failing and, given poor APRS coverage in Poughkeepsie due to having two iGates shut down (due to the aging radio geek population), I decided it’s time to simplify the radio interface. Given that HTs are designed to run with an external electret mic and earbud, the “interface” becomes basically some wires between the radio’s jacks, a repurposed USB plug on the bike helmet, and the PTT switch on the handlebar.
I expected to add a resistive attenuator to the earbud, but it wasn’t clear whether the mic would need an amplifier similar to the one in the APRS interface, so I decided to start as simply as possible.
The general idea is to anchor all the cables to a plate on the back of the radio, interconnect as needed, then “protect” everything with tape. The pocket clip has M2.5 screws on 26 mm (not 25.4, honest) centers, so that’s how it started:
Baofeng headset wire plate – dimensions
The four holes beside the tabs will serve as starting points for rectangular notches holding cable ties lashing the wires to the plate:
Baofeng headset wire plate – drilled
Like this:
Baofeng headset wire plate – sawed
That’s hot and nasty, straight from the bandsaw.
After some edge cleanup, add obligatory Kapton tape to insulate stray wires from the aluminum:
Baofeng headset wire plate – installed
The alert reader will note beveled corners on one plate and square corners on the other; think “continuous product improvement”.
The big rectangular gap in the middle of the plate provides (barely enough) finger clearance to push the battery release latch.
Now, to wire it up …
The dimensions of the recess surrounding the jacks on the Baofeng UV-5, just to have them around:
Baofeng headset jack socket – dimension doodle
Which came from measurements of both the Wouxun and Baofeng radios:
Baofeng Wouxun headset jack sockets – measurements
Blowback