Hello André,
>so I need to use a 100 Hz filter to kill it, or I
>copy nothing....
>Of course, using such a sharp DSP filter
>here, means that the S/N reports ts not realist here.
I believe S/N reports are realistic in any BW
if you are telling the BW at which the SNR has been measured.
Unfortunately in many S/N reports the associated BW is missing.
and therefore they are quite meaningless.
Just look at the reception report list of SAQ transmissions...
Another problem is that quite a few SDR users mix up the
SNR seen on the FFT spectrum with the SNR referred to the receiving "IF"-BW
in which the signal is demodulated.
E.g., if your FFT is set to a bin width of say 5Hz and a carrier lies 20dB over
the DANL (displayed average noise level) it will have a SNR of zero dB in a
500Hz "IF"-bandwidth and therefore will be barely audible.
73
Clemens
DL4RAJ
>-----Original Message-----
>From: [email protected]
>[mailto:[email protected]] On Behalf Of André Guyé
>Sent: Friday, August 08, 2014 10:56 AM
>To: [email protected]
>Subject: LF: Re: Testing now a new RX antenna on MF
>
>Hello Stefan,
>
>I?ll try many other tests to day and saturday at day time, including :
>
>* a 45° change in the K9AY direction of the 4 support wires ;
>* an extra relay system to use only one of the two out of
>phase verticals. That means it can works also as a single
>vertical monopole.
>
>Note : I have still the terrific local QRM carrier running on
>475725 kHz, so I need to use a 100 Hz filter to kill it, or I
>copy nothing.... Of course, using such a sharp DSP filter
>here, means that the S/N reports ts not realist here. But, the
>relative values are the most important in this test, even you
>know that the WSPR S/N is not linear for positives values.
>
>73, F6CNI.
>
>From: Guyé André <mailto:[email protected]>
>Sent: Wednesday, August 6, 2014 11:48 AM
>To: [email protected]
>Subject: LF: Re: Testing now a new RX antenna on MF
>
>Hello Stefan.
>
>I just start my RX now, hunting at your signal.
>
>I?ll test the both antennas K9AY (in the 4 possible
>directions) and the 2 els out of phase verticals, to see the
>diferences. On day time your signal is stable + / ? 1 dB.
>
>So, more info in the evening.
>
>73 F6CNI
>
>
>
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