With WSPRnet.org down due to some technical issues last night, I put on my big-boy pants and stepped out into a brave new world.
While I had run a few hours of QRSS10 in a previous early morning session while trying to reach VK2DDI’s Berry Mountain Grabber at a time when it was entirely too noisy in the land of Oz, I’ve never let the process run unattended for long periods. There was probably no reason to worry but I’ve had visions of a stuck comport or possibly a PC failure that results in an hours-long 200 watt+ dead carrier as I slept. I suppose I should have a little more faith in this hallowed junk that I have put together. To quote Han Solo, “she may not look like much but she’s got it where it counts, kid.”
I could not remember the original frequency that I had quoted David, VK2DDI, in the previous early morning session but I knew it was just south of the WSPR sub-band, probably near 475.500 kHz. That’s where I set up shop. Or so I thought. As Neil, WG2XSV / W0YSE, shows on his screen grab below, it more like 15-18 Hz high:
I should have known better. The IF for this system is an FT-920 without the high stability board and for that matter I knew from WSPR and experience with other digital modes that 15-18Hz was the norm. I used a little offset and got down to 475.505 kHz. That was close enough. I should note that I use a Thunderbolt GPS disciplined oscillator to drive the MF Solutions Transmit Downconverter but without an external reference input on the FT-920, about the best I can hope for is one moving target rather than two. Generally speaking, this works fine.
In the above screen shot from WG2XSV, you can see the adjusted frequency in addition to a peak plus the frequency drift during the course of the 6 minute transmission. What’s curious is how the drift seems to stabilize by the end of the sequence and the frequency seems to settle back down. I am going to have to think about why that is.
A final shot from WG2XSV showing the variety of signal levels and subsequently the QSB present during these two sequences. Special thanks to Neil for taking the time to snap these and send them to me. At the time of this writing, WSPR is still down so I will continue running QRSS10 until WSPRnet comes back online. Maybe even some longer variants are in order.