M17 is a digital radio modulation mode, like DMR, D-Star, or Fusion, developed by Wojciech Kaczmarski (SP5WWP) in 2019. Unlike other protocols, M17 has every part of the protocol open source. See: M17Project.org.

OpenRTX is an open-source project used to replace the firmware in commercial amateur radios. See: OpenRTX.org.

OpenHT is a hardware project working to build and Open Hardware Handy Talkie. It is based on FPGA design - a complete Lattice Radiant project for the LIFCL-40-7SG72C.

Because I enjoy building electronics and support open-source projects, I have started working with these projects. I’d like to build and deply a M17 repeater in my area.

The M17 protocol is designed to be used with radios having 4800 symbols per second 4FSK with a root Nyquist filter applied to the bitstream. Radio channels are 9 kHz wide, with channel spacing of 12.5 kHz. The gross data rate is 9600 bits per second, with the actual data transfer at 3200.

I’ve build the following hardware:

** Module 17 is a smart-mic hardware M17 implementation running OpenRTX firmware. ** TYT MD390 with the OpenRTX firmware and a small hardware mod can be used with the M17 Protocol. ** MMDVM_HS hotspots running the latest MMDVM_HS firmware.

And, I’m doing my best to help with the OpenHT project.

More to come!