Connecting BI7JTA MMDVM Repeater board to Motorola GM 340

I have this repeater board laying around very long time and i decided to try it out with gm340. i got the radio for our repeater RX. It was under my test and configuration before i installed it on repeater site.

The setup was strait forward. connect all wires plug and play style and start using it.

Basically setup the GM340 for flat audio, and turn off all telegram etc options.
Configure channel space to 12.5KHz if using simplex, and repeater mode the 12.5 wont work it give alot BER error, use 20KHz instead in duplex mode.

For set up MMDVM setup it normally your id, callsign etc. set audio levels to 50 and tune up the system. there is plenty guides for it on google.

So This setup was simplex. you can turn your gm340 for a long range digital hotspot like this! on my case i used PC with linux ubuntu and connected mmdvm to usb. (yes it will work that way too, no need raspberrys for that) total setup time was like 20min-30min.
For BI7JTA boards and more information go to his webpage here

Radio is atm in repeater site OH1DMRA Hybrid Analog/DMR

Here is a video how i did it 🙂


Remember to tune up your MMDVM

This is very important part. if you pass it, the BER will be very bad..

Use debug mode 1 or 0 for see that information on logfiles and tuneup pos centre threshold