[Lowfer] 74.5495 QRSS 60 as usual till at least 0600...

[JD]

Bob, Argo, and the spirit of Christmas be praised!  (To paraphrase Ebeneezer 
Scrooge.)

This is something of a miracle capture.  It was made with the sound 
completely turned down on the radio.  I use the auxiliary speaker output for 
the soundcard feed, not the headphone jack, so I have ample power to drive 
the clipper when needed.  I switch the speaker back in parallel whenever I 
want to listen.  The leakage through the audio amplifier was so low, 
however, that I couldn't hear anything at all when I went back to 
speaker--not even a peep of static, which was quite formidable on 74 kHz 
tonight, with frequent peaks at 50-60 dB above signal in a 250 Hz bandwidth. 
But Argo saw XRS4 anyway!

By the time I realized I had turned down the volume knob in the dark by 
mistake, Argo was reporting the signal at -112 dB to -114, and the 
background (in however many millihertz a bin is at QRSS30) as -120.  Try 
THAT with all your phony-baloney SNR numbers, WSPR!

I went to correct the audio level at the start of the second "4" but quickly 
realized that wasn't helping, so I put it back the way it was.

I'm always amazed at what Argo does, but this is a great demonstration of 
what it's capable of when everything falls into place to let you use its 
matched-filter characteristics to the fullest.  Bob's signal had the right 
element timings in the proper ratios, and by a miracle my radio was stable 
enough for a while that the signal apparently never drifted more than +/- 1 
bin width during the capture.  Argo was thus able to work with almost no 
energy being received, in the presence of truly intimidating noise.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: bob.jpg
Type: image/jpeg
Size: 24104 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/lowfer/attachments/20131009/732cccc0/attachment.jpg>