If you’ve read my last post, you’ll be familiar with the WSPR digital mode and how incredibly impressive it can be even in the most awful band conditions. I’ve decided to start a long term project with this mode, centered around the Raspberry Pi mini computer.
Modernizing the Beacon Concept
Through the General Class licensing process, I learned about the traditional Morse code-based propagation beacons that are present on HF bands. Given my background in software and Linux-based platforms, the idea of a modern, WSPR-based digital beacon is attractive. The idea was that if I couple that knowledge with the reporting / mapping system behind WSPRnet, I could probably discover some very interesting long term trends regarding 20-meter propagation from my transmitter.
I dug around and found the WsspryPi GitHub page. The discovery that a stock RPi could be used as a 100mW transmitter with the addition of a simple low pass filter helped put the plan into action.
Raspberry Pi Shield
Not being terribly well versed in soldering (I’m working on it.), or building electronics in general I sought out an off the shelf solution. I discovered the excellent TAPR 20m WSPR-Pi TX shield and less than a week later, the beacon is up and running.
For the near term, it’s just using some basic 18 gauge stranded copper wire, cut to length for the 20-meter band, inside the house. I’m running the beacon periodically whenever I have the opportunity to turn it on and activate the program. The map screenshot at the top of this article is a collection of reports from some day-long testing of the beacon.
Long Term Plans
Long term, I plan to extract the reports of my individual call-sign beacon receptions on WSPRnet and add them to a custom database. From there, the possibilities are extensive including reporting, mapping, long term projections and statistics outside of the WSPRnet platform.
How You Can Help
Spot that beacon! If you’re receiving 20-meter WSPR, make sure you’re automatically reporting to WSPRnet and the system can do the rest. I’d love to hear your feedback, whether it be on this site, Twitter, or QRZ. Let me know what you think.