LF: QRSS and QRN]

[Andre' Kesteloot]

Mike Dennison wrote:

> > >From Dave G3YMC
> > If Spectran and the other programs offer the capability to copy stations
> > 20dB below noise, in these circumstances this would only take you to s9,
> > which was certainly copyable with normal CW.  I admit the static levels
> > recently have been much higher than usual, and would not expect anyone to
> > attempt to work transatlantic under such conditions (or to even ragchew!)
> > I have two weakish carriers on the band, 136.7 and 137.8 which are
> > normally just above the noise.  I wonder how copy of these is on Spectran
> > with 20dB over heavy static - I can just about copy traces here in the
> > crashes.
>
> This misses the point. Spectrogram etc can copy CW up to 20db
> below 'normal' noise. But the duty cycle of static is much lower
> than noise, therefore there is a =much= greater advantage than
> 20dB. Using Spectrogram and QRSS, I can receive signals 100%
> in heavy static that would be impossible to read using normal CW
> at whatever speed.
>
> But in any case it is really up to the individual operator to use
> whatever technique he feels happiest with, and regardless of what
> technique is used, S9+ QRN is going to degrade it. Also QRSS is
> no good for ragchews, no matter how good the S/N is.
>
> I will try to demonstrate the advantage of QRSS in static by
> providing a WAV recording and Spectrogram plot on my web site
> (which make me the only LF operator hoping there's QRN tonight!).
>
> Mike, G3XDV (IO91VT)
> http://www.dennison.demon.co.uk/activity.htm