Hello,

There are lots of news about my project "New Packet Radio". Reminder, all info is here: https://hackaday.io/project/164092

A Chinese partner is now selling modems, assembled or kits, world-wide. Price is low : 80$ fully assembled, with aluminum enclosure. https://www.elekitsorparts.com/product/npr-70

I have improved the firmware, it's more stable, and it now allows the optional "FDD mode" (Frequency Division Duplex). With this optional feature, you can use the Master (=repeater) in duplex mode, with 2 modems (TX/RX) and a RF duplexer. The frequencies are different between uplink (from Clients to Master) and downlink (from Master to Clients). Clients are half duplex, with one single modem, switching very fast (300us) between uplink and downlink frequencies. The main goal is to put NPR master on tower where there is already a duplex repeater (FM or DMR or D-Star...), without interference between the 2 repeaters. Check all the documentation on hackaday for more details: mainly "Introduction", and "Advanced user guide". The new firmware is also on hackaday of course.

Finally, I have written an article for "IEEE spectrum"; It's currently on the web, and it will be on the paper version in a few days. I hope it will bring some advertisement to my project, and to the modern amateur radio movement. https://spectrum.ieee.org/geek-life/hands-on/build-a-longdistance-data-netwo...

If you have any question, just ask me.

73, Guillaume F4HDK