Like many of you, I have a Kenwood TM-D710A mobile radio in my car. Among its many fine features and qualities, it has native APRS capability built in. The fly in the ointment is the need for an external GPS receiver. Of course, the external GPS receiver comes with cables, one to connect to the D710 and one to provide the DC power the GPS receiver requires to operate. In prep for the Jefferson Cup on Sunday, I got out my GPS setup and put it in the car. I was reminded how much I hate the tangle of wires snaking all over the dash. I imagine them getting tangled in something important (like the shift, which is on the dash in my Odyssey) or falling and creating a distraction at a bad time. Either way, it feels like a safety problem.
Kenwood finally addressed this shortcoming by including a GPS receiver in the latest version, the TM-D710GA. I hate the cables, but not enough to buy a new radio. I assumed that surely someone had figured out how to retrofit older D710’s, and sure enough, they have.
I followed the instructions posted by W2DHS at http://www.w2dhs.com/2016/07/07/adding-gps-to-a-kenwood-rc-d710-and-possibly-tm-d710 for attaching the external GPS receiver to the back of the D710 control head and hardwiring it to data and power. I was already using the GlobalSat BR-355S4 GPS receiver “puck” (and you want the BR-355S4, not the BR-355 he used; the S4 can track over twice as many satellites simultaneously), so I had everything I needed. YO3HJV has posted instructions for putting a different, smaller GPS receiver inside the D710 control head; instructions at http://yo3hjv.blogspot.com/2010/01/oem-gps-inside-tm-d710-front-panel.html. Google Translate works well enough for you to follow the instructions if you go that route.
Working up the nerve to drill a hole in the D710 control head and start soldering wires to it was the hard part. 🙂 Following the rule “measure four times, cut once” (my improvement…), I got the GPS receiver mounted and hooked up. It worked first time, and is a dramatic improvement! From where I sit it looks like this: