I've been mucking around with trying to prototype the software for an embedded WSPR beacon controller, and rather than try to compile the entirety of WSPR/WSJT, I've been tinkering together the necessary bits to encode beacon messages on my own. That's all going well: I've got the 28 bit callsign, 15 bit grid square and 7 bit power level encoding figured out, as well as the convolutional coder, the interleaver. It all seems to work: my code is running on my macbook, generating wspr signals, and they are showing up on wsprnet.org.

But I have what will seem like a silly question: where are the length six gridsquares which are being reported on the spot page coming from? The protocol only reads four character grid squares. I thought they might be pulled from the User Info when you register on this site, but I entered that information, and they still aren't showing up in the spots database.

Just curious.