While M17 might sound like a new kind of automatic rifle (as actually, it is), we were referring to an open source project to create a ham radio transceiver. Instead of paraphrasing the project’s goals, we’ll simply quote them :
“The goal here should be to kick the proprietary protocols off the airwaves, replace DMR, Fusion, D-Star, etc. To do that, it’s not just good enough to be open, it has to be legitimately competitive.”
Like some other commercial protocols, M17 uses 4FSK along with error correction. The protocol allows for encryption, streaming, and the encoding of callsigns in messages. There are also provisions for framing IP packets to carry data. The protocol can handle voice and data in a point-to-point or broadcast topology.
On the hardware side, the TR-9 is a UHF handheld that can do FM voice or M17 with up to 3 watts out. The RF portion uses an ADF7021 chip which is specifically made to do 4FSK. There’s also an Arm CPU to handle the digital work.
We were struck by the similarity of the TR-9 to a cell phone since it has an LCD display, an SD card slot, and a 9DOF sensor. Maybe some open hardware cell phones and open hardware ham radios could find common ground.
This is quite ambitious, but generally, small ham rigs are having a resurgence. Having high-quality RF components available as chips makes a lot of difference.