Back to APRS

I once owned an expensive Kenwood handheld – perhaps a TH-D74 – that I had been excited about because I wanted to try APRS. To get on APRS at the time the option was to buy an expensive radio or to piece together (or home-brew) the audio interface, a GPS and the board to pull that all together.

Recently, Chinese radios have started to integrate these in reasonably priced handhelds so the last couple of weeks I’ve been trying the Vero VR-N76.

It’s a modern radio in the sense that you can program it over bluetooth as well as using the bluetooth (with it’s own app, or a generic app using the built-in KISS terminal) for doing APRS.

APRS

APRS – Automatic Packet Reporting System – is for sending telemetry packets over amateur radio. Packets can be repeated ‘digi-peated’ by radios set up for this to form a bit of a mesh. There’s no flow control, but packets contain some ‘path’ information which is altered when they are repeated so they don’t live forever and flood the network. Packets can also be ‘iGated’ onto the internet, which is a useful way to check your packets are getting out.

This image is from the very popular aprs.fi that can be used to view packets containing location information.

Here’s a trip from today. I’ve hovered over a packet sent from Albany Highway near Boddington. You can see on the map my packet was digipeated by VK6RMS at Mount Saddleback, then again by VK6RAW at Katanning, then iGated to the internet (but not repeated) by VK6SR at the Mount Barker repeater site. Here’s the packet that was iGated:


2026-01-07 18:07:45 AEDT: VK6MIB-9>APN000,VK6RMS-3,VK6RAW-3,WIDE2*,qAO,VK6SR-10:=3255.63S/11644.28Ek305/059/A=000925146.5 / 439.150

A few minutes later my packets were taking a different path:

2026-01-07 17:06:28 AEDT: VK6MIB-9>APN000,VK6RMS-3,VK6RMW-3,WIDE2*,qAO,VK6ZRW-10:=3306.66S/11656.61Ek321/052/A=001108146.5 / 439.150

Shout out to everyone involved in building and maintaining this infrastructure, – in this case WARG & Southern Electronics Group.

More Space APRS

NO84

Using space based digipeaters this weekend I had a couple of firsts. One was successfully having a packet digipeated by PSAT (Parkinson Sat – NO84). This is a 1.5U CubeSat launched in 2015 carrying a APRS transponder and a PS31 experiment.

I’ve heard this satellite before, but yesterday I had a shot at sending it a packet, I heard it digipeated, but didn’t receive it back well enough to decode it. I waited 30 seconds or so and had another shot with the same result.

Continue reading →

Terrestrial APRS

I took my first road trip within range of some earthbound digipeaters and iGates tonight. The D72 was secured on the dash of the ute, but using the dual band whip on the roof. I decoded one packet just out of Narrogin, I assume via VK6-RAW (I haven’t read enough of the manual to work out how to sort the list by time yet) but didn’t get any of my own packets digipeated back to me until I got much closer to Perth.

I had the beaconing mode set to Auto, but also sent through some manual packets when I could hear good signals from other packets being repeated. Next on the list is to re-read the manual in much more detail to get my head around all the settings.

Edited with BlogPad Pro

Accessing the ISS Digipeater

With a long weekend, and a major project at work behind me, I had a tiny bit of breathing space to play radio this weekend. What I should have been doing is putting in a couple of hours on the AllStarLink for my club (currently at about 30% finished). What prevented this was a new toy scored second-hand from eBay that arrived this week – a Kenwood TH-D72A handheld.

I grabbed this off eBay, the main attraction being it’s APRS capability, including: built in GPS, stand alone digipeating, and the ability to plug it into a PC and use it as a TNC. My first big plan for this, since I’m miles from anywhere, was to use it to get my staion on the ARISS map by having it digipeated by the International Space Station