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Message-ID: <65AECDF1F89AD411900400508BFC869F0D7551@pdw-mail-1.dera.gov.uk>
From: "Talbot Andrew" <ACTALBOT@dera.gov.uk>
To: rsgb_lf_group@blacksheep.org
Subject: LF: R Larry's signals last night 22/23 Jan
Date: Tue, 23 Jan 2001 14:28:50 -0000
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> Regarding I/Q sampling (is this the same as the old 11+ 
> selection, hi?) and
> filtering and smoothing to extract the phase, can we have a 
> program please,
> so that we can join in the fun?

You will need the hardware, something like a 56002EVM that I use to do
all the high speed ( ! ) DSP
Sorry !
Unless someone can be persuaded to write something similar for the
soundcard.
If 8 bit sampling is good enough - it usually is if no strong signals
appear in the IF passband that exceed the noise by more than 30dB - one
of the sampling options on my PIC based interface serial A/D will I/Q
sample a 750 - 1250 bandwidth centred on 1kHz and a PC can do the rest.
A commercial version is available from HF-Instruments
WWW.HF-INST.CO.UK

Saving raw data overcomes the problems of setting wrong colour
thresholds, FFT sizes and the like and means you can go back and replot,
changing any parameter at will.   Saving two 16 bit numbers per sample
means 24 hours recording at 3.9Hz (8000Hz / 2048) generates a file of
just 1.35 Meg.

'JNT


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