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From: k2ors@comcast.net (Warren K2ORS/WD2XGJ/WD2XSH/23)
To: rsgb_lf_group@blacksheep.org, LF-Group <rsgb_lf_group@blacksheep.org>
Cc: Dick Rollema <dickrollema@casema.nl>
Date: Tue, 07 Nov 2006 14:35:32 +0000
Message-Id: <110720061435.13730.455099B400023157000035A222007358340B97010D0A020E06979D0E03@comcast.net>
Subject: Re: LF: DSP-filter for aural CW
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Reply-To: rsgb_lf_group@blacksheep.org
Status: O

Hi Dick,

   Wolf's Spectrum Laboratory can be used to exactly that. 
http://people.freenet.de/dl4yhf/spectra1.html


--
73 Warren K2ORS/WD2XGJ/WD2XSH/23
FN42hi
http://www.w4dex.com/wd2xgj.htm

 -------------- Original message ----------------------
From: Dick Rollema <dickrollema@casema.nl>
> To All from PA0SE
> 
> Does someone know whether a DSP filter using the sound card of the computer 
> can be found on the internet , that can filter the audio output of the 
> receiver with an adjustable bandwidth down to, say, 20Hz or so?
> 
> I use a passive audiofilter between the receiver and the headphones with 
> four tuned circuits. It has a bandwidth of about 25Hz, a centre frequency 
> of 900Hz and a linear phase characteristic to avoid ringing.  But perhaps a 
> DSP filter could do even better.
> 
> 73, Dick, PA0SE
> JO22GD
> 
> 
>