[Lowfer] Lowfer SIW QRV

[Garry]

With the help of Bob, NK9M, I fired up lowfer SIW for the coming winter 
season. As before, 2 frequencies are used: 185.2993 kHz on M,W,F and 
185.185 kHz on T,Th,Sa,Su. Switchover is at 1800Z. At least that's 
what's intended. Because of the daylight/standard time shift it may be 
off an hour. On the watering hole frequency the transmission sequence is 
QRSS30, QRSS60, ... On the lowfer frequency 3 different transmission 
formats are sent each hour: WSPR-15, QRSS25, then Opera32.

The reason for QRSS25 rather than QRSS30 is to keep the sequence length 
just under an hour. Running ARGO, etc. at rate QRSS30 works fine for 
displaying the received signal. Opera32 has been added to provide a bit 
more detection sensitivity than WSPR-15. Careful, the software is rather 
"imaginative" with its deep search detection (bench testing to a dummy 
load yesterday resulted in a 136 kHz decode from Italy!). Unlike WSPR, 
the Opera dial frequency cannot be changed from the fixed offerings (you 
must pretend it's 136 kHz and tune so the demodulated signal audio is 
about 1500 Hz) and the only way to keep reports private is to break 
connection to the internet (no upload spots box to uncheck).

One way to run Opera, WSPR-X0.8, and Argo simultaneously to detect all 3 
transmission types is to set the USB receiver tuning dial to the desired 
frequency less 1500 Hz; i.e. 183.685 kHz. This works directly for 
Opera32 (though it will incorrectly associate the tone with a base 
frequency of 136 kHz) and ARGO (centered at 1500 Hz). For WSPR-X0.8 in 
mode WSSPR-15 rather than WSPR-2 and with the same dial frequency, the 
demodulated audio frequency has to fall between 1600 and 1625 Hz, not 
the 1500 Hz it really is. Accomplish this needed shift via the Advanced 
tab setting for the Rx BFO (Hz): . For example, to raise the audio tone 
to say 1610 Hz specify a BFO value of 1390 Hz.

73, Garry, K3SIW, EN52ta, Elgin, IL