Content-Transfer-Encoding: 8bit
Date: Fri, 6 Aug 1999 10:13:11 +0100
Message-ID: <199908060913.KAA17894@post.interalpha.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii; format=flowed
To: rsgb_lf_group@blacksheep.org
From: drassew2@interalpha.co.uk
Subject: Re: SV: LF: eclipse
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Sender: <majordom@post.thorcom.com>

There is one saving feature if AGC cannot be turned off.  If the signal to
noise is low, say 10db or worse, then you can at least mesaure S/N using
this technique.  The technique may not necessarily be of value at LF / HF
where noise level is likely to vary with propagation, but where noise is
equipment dominated is certainly allows accurate measurements to be made.  A
few years ago I made propagation measurements on microwave beacons using an
8 bit A/D (before programming soundcards became easy) and used S/N of the
carrier in 3kHz as a measure of signal strength.

Andy G4JNT

>Forwarded from Rik Strobbe:
>
>>A software team from the Belgien amateur radio society UBA has developed a
>>programme that can be used to register the fieldstrength measurements. All you
>>need is a PC with Win95/98 and a soundcard. The audio output of the receiver
>>is fed to the input of the soundcard.
>
>AGC (which is present in most amateur receivers) will make such measurements
>almost useless (unless the AGC can be disabled).
>
>Please correct me if I'm wrong...
>
>73, Johan
>
>
>
>