There’s been a recent upswing of APRS on the HF bands using EA5VHKs VARA modem. A recent update to the software allows larger KISS frames which makes APRS more efficient on the HF bands.
A little bit about VARA
VARA is an Orthogonal frequency division multiplexing (OFDM) method to transfer data. OFDM is primarily used in WIFI and other high speed data protocols in the cellular telephones. A better explanation than I can give on OFDM can be found by doing a simple Google search, here’s a link to one I found: Concepts of Orthogonal Frequency Division Multiplexing (OFDM) and 802.11 WLAN.
EA5VHKs description says VARA “brings state of the art Military grade technology to new and existing HF data.”
Folks have settled on dial frequencies at 7.0835 on 40 meters and 14.103 on 20 meters.. NA7Q posted a Facebook post showing position beacons using APRSDroid to send and receive messages and VARA on a mini pc with a USB GPS dongle.
I got to watch all of that happen, plus another longer trip a day or two later. I was able to pick him up on 40m through places I know traditional VHF beaconing would have failed. It was impressive to say the least.