Graham es Co
While Opera es other data modes are an alternative to CW for a change they
need another level of demodulation and cannot really compete with the basic
CW mode or QRSS CW.
I often see traces of all data modes that could easily be identified in QRSS
but they do not decode therefore the purpose of the transmission is lost.
de mal/g3kev
----- Original Message -----
From: "Graham" <[email protected]>
To: <[email protected]>
Sent: Wednesday, July 25, 2012 4:07 PM
Subject: Re: LF: 4X OP32 report
> schrieb Stefan, :)
>
> Why do you think so?
>
> Its linked to the DSP engine in Op , there is a timing issue , if
> other applications lock the sound card at a different rate , due to
> the % tolerances , low level decodes can be lost , noting, Op is a
> 'data mode , so the overheads in the transmission are much higher ,
> as are the DSP engine requirements , as can be seen with 'older' pc's
> cpu loading can be a issue , as is a one-pass system , all the
> processing is taking place in real time
>
> But on with the show ,
>
> 73 -G..
>
> -76 dB in 28 mHz b/w , what is that when translated to 2.5Khz
> B/w ?
>
>
>
>
> --------------------------------------------------
> From: "Stefan Schäfer" <[email protected]>
> Sent: Wednesday, July 25, 2012 3:08 PM
> To: <[email protected]>
> Subject: Re: LF: 4X OP32 report
>
> >
> > Am 25.07.2012 15:51, schrieb Graham:
> >>
> >> Pity nothing decoded in the US last night , but signal 's in 1500
> >> /2000 mile range where quite substantial ...
> >> from this , it seems that propagation on 136 is really linked to
the
> >> seasons ?
> >
> > Yes (of course) and no. W1VD received me quite well a few weeks ago, see
> > https://dl.dropbox.com/u/19882028/LF/07_July2012.jpg
> > Not to forget W1TAG:
> > https://dl.dropbox.com/u/19882028/LF/DK7FC_Juli2012.jpg
> >
> > So there is some propagation in summer but of course it depends on the
> > solar activity. Don't know how the condx have been yesterday.
> >
> >> One point from previous trials , If Spec-lab is used with Opera
> >> , then SL must be set to 48Khz sample rate , or OP can loose
low
> >> level decode sensitivity.
> > Why do you think so? As long as the frequency range of a SSB bandwidth
at
> > audio levels passes through the SL filter, then it should be fine. So 8
> > kHz SR should be fine. Of course it depends on which shift frequency you
> > have to use. I have to use 11 kHz shift and so i choosed a SR of 30 kHz.
> >
> >
> > 73, Stefan
> >
>
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