Conducted a bit of an experiment 31 January 2024 to check out tracking on HF APRS. I ran HF APRS at the same time I ran the standard VHF APRS and compared the results as shown on APRS.fi

VHF is a FTM-400 with a roof mounted Comet CA-2x4sr, 50w

HF is a FT-900 with a SharkStick Mini mounted to the hatch of my 4Runner (win11 minipc to run VaraHF and APRSIS32). Radio was set to approximately 25w

This 330 mile (530km( trip features some greatly varying terrain: gorges, canyons, high desert plateaus, mountain forests and more. I knew that there were few APRS iGates and Digipeaters along the route for VHF, but they were sparse. I was relying on my home station to do all the heavy lifting for the HF side, and a few other stations also picked up and gated my HF packets

I think the screenshots speak for themselves. Every single HF packet was received by a gate, with the longest travelled packet being about 750 miles (1200km). My home station did pick up most of the APRS packets, with three other stations picking me up when my home station did not: NA7Q, VE7EPT and WA7GMX. The first half of the trip wasn’t even picked up on VHF, despite driving under two different VHF digipeaters and iGates. Their altitude was too much while driving through the gorge.

The HF APRS radio was set to 7.0835mhz and I used unaltered “GeniusBeaconing” for both.

One observant station to the northwest of my path, W7MIS, caught my track online. I received a message from him over APRS (VHF to HF) asking me how I was doing what I was doing. He has a few iGates in the Boardman area and, knowing my location, he knew that no VHF should be reaching a gate, and was curious to know how I was tracking on APRS. He’s on HF APRS now.