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

[jrusgrove at comcast.net]

> Try  THAT with all your phony-baloney SNR numbers, WSPR!

Nothing phony about SNR being referenced to a particular bandwidth. Don't like the bandwidth it's 
referenced to just adjust with 10 log (BW1/BW2). Guess you would then think dBm is phony-baloney as 
well ... if the "m" isn't exactly to your liking.

Argo has a wide range AGC which explains what you witnessed. Have you run the same test with WSPR's 
AGC system?

Jay W1VD  WD2XNS  WE2XGR/2 WG2XRS/2



----- Original Message ----- 
From: "JD" <listread at lwca.org>
To: "Discussion of the Lowfer (US, European, &amp;UK) and MedFer bands" <lowfer at mailman.qth.net>
Sent: Wednesday, October 09, 2013 2:34 AM
Subject: Re: [Lowfer] 74.5495 QRSS 60 as usual till at least 0600...


> 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.
>
>


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