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Right .. thanks Andy ... that makes sense
... looking at rms power in a bandwidth and not the spot noise power
at one frequency (+/- spec bw) ?
why the 100 hz , as the wspr
window is 200 hz wide , is the software looking +/- 50 from
the decode frequency ?
To make use of the level in terms of
the path suitability for say a data transmission ... is there a
quick way of working backwards , if you
know the minimum s/n that the mode will
handle, using the reported wspr result ?
Tnx- G ..
Sent: Wednesday, September 23, 2009 9:50 PM
Subject: Re: LF: s/n shown by wspr .... what is it actually showing
?
Its normalised to 2500Hz banbdwidth - approximately an SSB filter's
worth.
So +20dB in 100Hz = -3dB in 2500Hz.
Andy
On 23/09/2009, Graham
<[email protected]>
wrote:
Just watched Dave's G3YXM wspr signal
on spec-lab ,
Spec-lab showed the signal to be a
constant 20 dB over the back ground noise floor of the rx
so in my book that's 20 dB
s/n
The wspr decode is showing -3
dB s/n ?
What is it actually displaying
?
G ..
--
Andy
www.g4jnt.com
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