[Lowfer] WM midnight mania

[Garry Hess]

Jay, thanks for the heads up that both WM lowfers are again QRV. Looked 
at the watering hole last night with e-probe/SDR-IQ and saw XR well but 
nothing of WM or WM2. MP was temporarily QRT and NDB LNT wasn't copyable 
either so don't think conditions to the east were good. This morning 
even daytime copy of EAR is somewhat on the short side. Will try again 
tonight.

There is currently a plethora of 500 kHz WSPR activity. WD2XSH/10 and 
/17 are making it over the Atlantic. /12, /29, and /37 are also 
transmitting and quite a few monitors are reporting reception to 
http://www.wsprnet.org/.

WSPR is a great mode, but I think its virtues are being over-rated by 
some. Reliable WSPR decoding occurs on average with SNR 28 dB below 
thermal noise for 2.5 kHz bandwidth. Statistical variation allows 
occasional detection as low as -31 dB SNR (see 
http://wsprnet.org/drupal/node/1453). That's very impressive, but not 
unheralded. WOLF-10 can work down to -45 dB SNR, which is 27 dB better 
than CW and comparable to QRSS-60. These good modulation schemes simply 
approach their Shannon limits. They differ by the amount of information 
conveyed per unit time. To reliably detect signals at lower SNR you give 
up information rate. WSPR conveys nice packets of information in 2 
minutes. Weakest-signal Wolf10 may take 45 minutes. Weakest-signal 
QRSS60 takes 22 minutes just to convey the letters "XR", but I'm sure 
glad many lowfers transmit that mode!

My 2 cents,
73, Garry, K3SIW, EN52ta, Elgin, IL
SIW at QRSS30 on 185.185 kHz