The design

Here is a "safe" APRS interface for BaoFeng and other radios.

Sample schematic:

    / [pdf]

Motivation

https://github.com/skuep/AIOC works but it seems to have a couple of problems:

  1. RF feedback problem with monopole antennas

  2. Hard-to-source exact 3.5mm and 2.5mm audio connectors

  3. Mechanical fragility of these "half-cut" (chopped off) and then only SMD-style soldered TRS connectors

  4. Reliance on the PCBA process to get a working product

I believe we can reduce the cost by a lot and also make the whole thing homebrew-able without placing a JLCPCB PCBA order.

Also, we are hoping that we might be able to use ready-made off-the-shelf audio cables in our design.