Sunday, January 15, 2012

Propeller does WSPR

Through Eldon, WA0UWH I have discovered another blog to add to the blogroll: that of Jeff, KO7M. Jeff is interested in a lot of the same things I have been (including light aviation: an ambition of mine when I was in my 20s but which I could never afford to take up.) But what really piqued my interest was that he has just got a Parallax Propeller to generate a WSPR signal.

This is one of the things I was interested in trying. But I never got further than wondering how to implement the fractional frequency shifts of the WSPR signal, which uses 4 tones shifted by just under 1.5Hz from each other. Jeff has apparently found that a 2Hz shift is good enough to be decoded, allowing WSPR to be sent using the integer frequencies the Propeller chip can easily generate.

Once I have finished the Tiny Keyer project and can get back to the Propeller I will be trying this myself. My ambition at the moment is to make a multi-band multi-mode (OPERA, WSPR and perhaps QRSS as well) standalone beacon with an LCD panel to enable me to choose the band and mode. We'll see how far I get, but having two other people working on the same ideas should certainly make the task easier!


Jeff ko7m said...


Happy to share any code and ideas for your beacon or any other project. Let me know if you have any questions.

Regarding aviation, it is a passion of mine. Should you ever find yourself in the Seattle area, let me know. I would be honored to take you flying Super Cub style...

Best 73's de Jeff ko7m

Alex Hill said...

Once you've done all the hard work Julian can you publish it here. I've been looking to have something like this for a long time but it's not my core capability shall we say. It would beat having a PC and rig set up running a beacon as well as an invaluable tool for testing antennas in the real world.


Unknown said...

Yes I will, Alex, though you'd best keep an eye on Eldon and Jeff's blogs as they are making faster progress than I am.