https://elekitsorparts.com/product/npr-70-modem-by-f4hdk-new-packet-radio-over-70cm-band-amateur-radio-packet-radio

Info: https://www.arednmesh.org/content/npr-new-packet-radio-available

https://opensource.com/article/17/9/packet-radio

https://hackaday.io/project/170710-esp32-tnc-and-audio-relay-for-hfvhf-packet-radio