Hello all,
On the WSPR website,
http://physics.princeton.edu/pulsar/K1JT/wspr.html
I find this statement:
The program can decode signals with S/N as low as -28 dB in a 2500 Hz
bandwidth. <<<
I have been looking at decodes on WSPR Spots
http://wsprnet.org/olddb
and it appears that on bands from 160 m and up a SNR smaller than -25 dB
is a bit rare.
On 630 m these low level decodes are found more often, though decodes with
an SNR of -30 are rare.
In the nigh of Saturday to Sunday, I had 14 decodes from WG2XJM.
Two of these showed a SNR of -33 dB.
I have never seen such a low SNR before and a search through the WSPR
Spots database showed a decode from a French listener of WG2XJM with an
SNR of -31, which is the lowest SNR I could find.
As far as I know the bandwidth of the WSPR decoder is set to 200 Hz, so as
long as the receiver bandwidth is larger than 200 Hz, decoding should not
be effected. My receiver bandwidth is 540 Hz.
So, has anyone an idea what is the cause of these low level WSPR decodes.
Best regards,
Roelof Bakker, pa0rdrt
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