I've been working on DMR APRS and its now in the latest release.ve7mdt wrote: ↑Fri Nov 18, 2022 3:09 amSorry, Roger, I haven't been back to this forum lately and missed your post.
I haven't looked at any implementation of the Bell 202 modem or 1200 AFSK packet radio, but I know it's been implemented in many small microcontrollers, even PIC, like the TinyTrak product (which version 1 was released on QST for its code and schematics many years ago), which is an encoder.
It's basically 2 audible tones modulated on to the FM audio. 9600 packet is entirely different as that's GMSK iirc.
I don't have time to investigate whether the hardware would be capable of sening 1200 tones per second, but I think its not very likely, as the hardware is only designed to send slow speed DTMF tones.