Dear Jim,
I would agree on your conclusion. Theoretically, a marginal "M" qrss signal
with 6 dB SNR in 0.5 Hz noise bandwidth would rank -
34 - 3 + 6 dB = -31 dB on K1JT's scale, which is related to 2.5 kHz bandwidth.
But the spectrogram impression may be a little
"unfair", as a QRSS-3 signal with all the power contained in a single FFT bin
would certainly appear brighter than this WSPR signal
which is diluted over 6 Hz.
Kind regards
Markus, DF6NM
----- Original Message -----
From: "James Moritz" <[email protected]>
To: <[email protected]>
Sent: Sunday, January 18, 2009 7:23 PM
Subject: LF: WSPR SNR
Dear LF Group,
The attached bit of spectrogram was set up for QRSS3 reception and shows 2
succesfully decoded WSPR transmissions from G4WGT at -30 and -27dB SNR
respectively. I think this shows that this mode should compete well with
QRSS3 for readibility.
So far, I have:
1654 1 0.6 0.503500 0 G4JNT IO90 30
1752 -28 1.0 0.503599 0 G4WGT IO83 37
1758 -30 1.0 0.503599 0 G4WGT IO83 37
1810 -30 1.1 0.503599 0 G4WGT IO83 37
1814 -27 0.9 0.503599 0 G4WGT IO83 37
Cheers, Jim Moritz
73 de M0BMU
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