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Date: Mon, 12 Jan 2009 20:44:08 +0100
From: =?ISO-8859-1?Q?Wolfgang_B=FCscher?= <dl4yhf@freenet.de>
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Subject: Re: LF: RE: RE: WSPR beacon on 136kHz - QRT
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Hi Dave,

Except from trying WSPR (the standalone GUI version) a few times on 
shortwave and LF, I can only tell you that..
 - it's very important to sync the local PC time accurately - but sure 
that's not the problem here
 - the soundcard's sampling rate may be a problem: The WSPR GUI uses 
12000 samples/second, which is a bit exotic,
   and some soundcards/drivers have a problem with this (and deliver a 
inaccurate sampling rate which causes problems in WSPR)
- the receiver's frequency drift must be low enough (a Hz per 2-minute 
interval already degrades decoding).
   Not a real problem unless your receiver is a converter, moving the LF 
signal to a higher shortwave frequency
    (I've seen a signal on 30 or 40 meter from italy, which was very 
strong, but almost unreadable due to the drift)

Does Jim's signal draw a "red" stripe on the WSPR spectrogram (I think 
it should) ? If not, the audio level may be too low.

HTH, cheers,
   Wolf .

Dave G3WCB schrieb:
> Hi Jim, LF.  
>
> Sadly no decodes from M0BMU or DF6NM on 136 last night.
> M0BMU was clearly audible and was showing on the waterfall display.
>
> I'm using WSPR 1.01_r1023, and it worked fine on 500kHz the other day.
>
> Am I doing something wrong? (well, yes, obviously, but what!)
>
> 73, Dave G3WCB IO91RM
>