Well…. It’s working but not as easy as I thought to build. Modifying the little sound fob is difficult as it requires removing some surface mount components and adding some some 33ga wire leads to pins on a super-small IC. Not something I can poop out quickly as my eye’s even with glasses are pretty bad I’m finding. I have learned a TON though by building it and have enough parts to build another of the BF-888/CM108 version. Since the CM108 fobs are so cheap, I have a few coming and will likely get better and faster at modifying them.
Taking the Baofeng BF-888 apart and doing the needed mods isn’t difficult and makes for a great CHEAP platform for a node radio at $8-$10 each on Amazon.
I also still have a DMK URI and am making up a 25-pin connector for another BF-888. This is the easiest way to build one. The DMK URI (universal Radio Interface) runs about $120 and there are similar offerings from Repeater-Builder for a wire-configurable interface that they call a RIM (Radio Interface Module).
If you happen to have a Kenwood or Alinco radio that has the 9-pin serial on the back, Repeater-Builder has a plug-n-play option called an Alinco-RIM. This is a 9-pin to USB affair and it makes this SUPER simple. This is what my high-power node at home 548950 is running. Antenna is a 17′ co-linear and it has great audio and great coverage.
I’m definitely having some RF issues with my home-brew BF-888/CM108 node. Ended up buying a cheap shielded network cable that I’ll cut up and use as shielded cables in the next version. I also hot glued the radio on its side with the RF board on the opposite side of the Raspberry Pi. This puts the BF-888’s heatsink between the radio board and the computer as some extra shielding.
It’s a bit frustrating as there are a bunch of videos of people twisting these types of nodes together and ‘having no issues’… assuming they are sparing all the trials and tribulations for the sake of a ‘look what I did’ video. 🙂 Each version I have played with so far has some sort of issue that needs worked out. Mostly audio quality and RFI.
I’ll keep plugging away at it….