Message-ID: <008001c3c068$e540b220$0401a8c0@vaiosn>
From: "Stewart Nelson" <sn@scgroup.com>
To: rsgb_lf_group@blacksheep.org
References: <28.41604b50.2d0a7870@aol.com>
Date: Thu, 11 Dec 2003 20:32:04 -0800
MIME-Version: 1.0
Subject: LF: Re: Soundcard bandpass filter?
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Hi David and all,

Just realized that I failed to mention that you also need some gain,
because the desired signal is only a tiny fraction of the energy in
your .wav files.  You can specify gain in the passband of the filters,
and/or use the Transform->Amplitude->Amplify command as desired.

73,

Stewart KK7KA

> Does anyone know of a programme that can produce an audio bandpass filter
> from a soundcard?
>
> I'm trying to find something that will allow me to specify a frequency of
> interest and to have the DSP remove signals above and below two cut-off
> frequencies.
>
> Reason: twofold, 1) I've recently recorded some EME signals from 70cms as
> .wav files and I'm trying to recover reasonable audio.
> 2) It occurs to me that the LF QRSS beacons regularly visible from VO/RU/
> etc. are actually very strong and it should be possible to filter and speed up
a
> stored QRSS file to something like normal CW........just for fun
>
> Would the new 'filter' incorporated into  V2.3 spectrum Lab do this?
>
> Seasons greetings es 73
>
> David   G0MRF
>