I thought it’d be a good time to open the discussion and perhaps testing of HF APRS. There’s a couple of different implementations of it, but the HFAPRS for this discussion is based on APRS messenger developed by Chris Moulding G4HYB from cross-country Wireless. Like its cousin APRS on VHF, HFAPRS provides the user with a way to send out his or hers position reports which can be received by an igate many hundreds or thousands of miles or kilometers away. Once in an igate, the position report is routed to aprs-is where it can be seen and visualized in aprs applications like APRSDroid, or graphically displayed on websites like aprs.fi.
The operator using HFAPRS also has bi-directional messaging available to them. Messages can be direct Station to Station, via a digi if one is available, or from Field Station to internet and vice versa provided the Gateway is configured to gate from the net to RF.
For the sake of this discussion I’m going to explain several different ways to engage using HFAPRS. The first method is using APRS messenger app from cross country Wireless. You can download aprs Messenger here: http://www.crosscountrywireless.net/aprs_messenger.htm it’s a free app and works just like wsjt-x or any other a f s k mode. There are 5 ways to use aprs messenger in the context of this discussion.
1. As an igate
2. As a digipeater
3. As a bi-directional aprs messeging client
4. To send and receive position reports.
5. Any combination of the above.
APRS Messenger runs on windows, but can also run on Linux with wine. It doesn’t require a TNC since it actually acts as a soft TNC, with your audio interface and radio. This is the difference between the hardware-based VHF aprs using popular aprs enabled radios, a kiss TNC like the Mobilinkd or trackers from bionics and Argent data.
Another way to engage with HFAPRS is with Android app, DroidPSK. DroudPSK allows operators in the field with an Android device and a WolphiLink interface, to send out the position reports using their tablet or smartphone, and radio. At the moment DroidPSK only offers the ability to send out position reports, and can’t receive messages or position reports from others. Still the ability to send out a position report can be critical to let others know your exact location in the field. DroidPSK can be purchased from the Google Play Store, but I suspect most Android users already have it.
It’s important to note DroidPSK and aprs messenger work hand-in-hand to provide a total solution. The system will not work unless there are aprs messenger igates setup and running. However unlike it’s VHF cousin a single igate is enough to cover several countries in Europe, easily several States/ Provinces or larger regions on other continents, so fewer of them are needed.
The global frequency for HFAPRS is 10.149.7.
APRS Messenger can send receive in multiple modes eg PSK63, PSK250, MFSK16, GMSK, and connected modes ax.25 PSK63, ax.25 mfsk, ax.25 GMSK.
The software is free and there are no Hardware requirements other than your audio interface and radio. So this can be much easier and less expensive to get into than VHF aprs. I hope this small introduction leads to a discussion and ultimately an HF APRS party in the near future.
If you’re reading this post on oh8stn.org and you’re a Facebook user I would suggest joining the portable digital and qrp group on Facebook. This is the group where we organize all of the different tests days four different modes.
73
Julian oh8stn
