Re: LF: 9kHz: soundcard RX

[M0FMT <m0fmt@yahoo.co.uk>]

never blown a sound card up yet in over almost ten years of use. Two back to back diodes on the antenna lead close to the input plug. Don't leave it connected during thunderstorms. Most modems are left connected day and night to very very long over head telephone wires for years with out problems. Vastly over hyped problem.

73 es GL petefmt

--- On Wed, 3/3/10, Horst Stöcker <horst.stoecker@web.de> wrote:

From: Horst Stöcker <horst.stoecker@web.de>
Subject: LF: 9kHz: soundcard RX
To: rsgb_lf_group@blacksheep.org
Date: Wednesday, 3 March, 2010, 9:32

>And what about a simple band pass filter to supress the 50Hz and it's harmonics? Necessary or dispensable?

You can hear (!) the difference. I just took a 10mH coil from Reichelt to improve my soundcard-RX before one of the last SAQ activities.

Despite of more or less excellent digital filtering of SpecLab it's a good idea. One should not keep the soundcard busy with unwanted signals.

What I am not sure about is the use of an audio transformer. It might have some influence to the signal. As it just has to keep the soundcard from beeing blown it might be a good idea to take a cheap soundcard instead of the audio transformer - and maybe a second in spare.

Stefan, what USB-soundcard you bought for 10 EUR ?

Horst DO1KHS
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