APRS with a PC and handheld transceiver

The problem

I want to send and receive APRS beacons, and for received beacons, I want to see them in a way that makes sense. Positions overlaid on a map would be nice, for example. The Alinco DJ-MD5XLT advertises APRS capability, and I have successfully transmitted a beacon straight from the radio, but as far as I can tell it cannot decode and handle received APRS signals. So I want to connect the radio to my computer and use whatever software is available to read and archive APRS signals.

Hardware

For this exercise, I used my handheld Alinco DJ-MD5XLT and Alinco DJ-W70. The MD5XLT is a DMR-capable radio with GPS and APRS functionality, but as described above it doesn't handle incoming APRS transmissions and is therefore of limited use. The DJ-W70 is a new handheld analog transceiver from Alinco, and boasts an 8-watt transmitter.

I used the Digirig Lite to connect my handhelds to the computer. It requires a radio-specific adapter that attaches to the mic/speaker jacks on the radio side and a single 3.5mm jack in the Digirig Lite. Annoyingly, the DJ-MD5XLT requires an Icom adapter while the DJ-W70 uses the Kenwood/Baofeng standard.

Software

I first configured Digirig Lite according to the instructions on the Digirig webpage. It's straightforward enough, and worked for me without further troubleshooting, but just MAKE SURE TO COMPLETE ALL THE STEPS. I'm looking at you, Ben! I've configured both my Mac and PC using this guide and have had minimal issues on the Digirig front.

Next, I downloaded Soundmodem, by far the sketchiest-looking website in this exercise. But the software itself seems pretty high-quality and makes up for the minutes I spent second-guessing my life choices.

Soundmodem takes the Digirig input and makes a TNC stream for our next program. I came across this webpage and found it helpful in figuring out exactly what I was trying to achieve. What was I trying to achieve? PinPoint APRS, the next bit of software, needs a TNC stream to work. Digirig gives an i/o audio stream. Soundmodem does the magic in between. Make sure to download ptt-dll.zip from the Soundmodem webpage, and put those two DLL files wherever your Soundmodem executable lives.

Finally, download and install PinPoint APRS. In tools → options, you'll set your callsign in the APRS tab, and in the TNC tab, make "TNC type"="network KISS mode" and at the bottom of the tab, under "Network KISS TNC Settings", make sure the "Port" is set to whatever you configured for "KISS server port" in Soundmodem's settings.

That's it, in a nutshell! I tuned the radio to 144.390 (no CAT control for the little handheld, you just tune it from the radio itself), and in PinPoint I selected "Connect TNC". Then the reports started arriving! There's an interesting APRS-IS feature in the program, where you can connect to an online APRS stream and filter it for the stations within a certain radius of your position. It could be useful to supplement what you're hearing on the waves, but make sure to keep it disabled at first, or else you might think your radio is successfully hearing APRS transmissions when it's just APRS-IS (I experienced this first hand).