First WSPR15 transmission decoded successfully

After a LOT of effort, G8HUH managed to decode my WSPR15 transmission on 137.607kHz at 1815 this evening. Even with a very low (1.7MHz) LO, the drift was still 4Hz in the 15 minute TX period, mainly due to the FT817 I think. At only -32dB S/N decode this was actually not as good a result as with WSPR2 over the 250km path. Short of force cooling the FT817 or using a rig with a TCXO reference, there is nothing more I can do.

My WSPR15 transmissions were also copied and decoded by G4FFC and G4FEV.

CONCLUSION: WSPR15 is a much more tricky mode to use successfully unless the transmission is very stable. This is the screenshot Tom G8HUH sent me.

30uW ERP 137.607kHz WSPR15 signal received by G8HUH 

137.5kHz WSPR15 tests

Using a very stable external signal generator as my 10.0000MHz LO 5dBm injection, I'm now in a position to try WSPR15 with a stable signal. After a quick frequency check with WSPR2 I propose to switch to WSPR15 with its greatly improved weak signal capability for this evening and overnight. WSPR15 activity takes place in the 25Hz slot just above the WSPR2 activity.

Please let me have any reports.

The first WSPR15 transmission will occur at 1600gmt.

Update: Tom G8HUH reported an upward drift of 5Hz during the 15 minute TX burst, so I've moved the LO to 1.7000MHz and the FT817 to 1.836kHz. Drift (all due to the FT817) is now 1Hz. Awaiting decodes. 

137.5kHz ...it's getting repetitive

Well, I've had the 137.5kHz WSPR2 beacon running for about 18 hours now, almost continuously on a 25% TX cycle. I've tried to drum up reporters by posting on the WSPRnet chat page, RSGB LF Yahoo Group and the LF Blacksheep reflector, plus a few direct emails to stations likely to copy my signal.

Consistent 137.5kHz WSPR spots from G8HUH at 250km, but no others!

All I've managed are the very consistent reports from good old G8HUH at 250km. The signal is obviously spanning this distance without any issues so why no others reporting?

Later I am going to replace the 10MHz LO in my transverter with the stable source from my synthesised signal generator and have a go tonight at WSPR15 (15 minutes TX periods) and see if that gets me a few more reports. It should be several dB more sensitive. If that fails to get anywhere, then I am calling it a day on 137kHz. In terms of returns for effort, this is not good value.