Return-Path: Received: (qmail 10773 invoked from network); 26 Mar 1999 13:55:41 -0000 Received: from magnet.plus.net.uk (HELO magnet.force9.net) (195.166.128.26) by medusa.plus.net.uk with SMTP; 26 Mar 1999 13:55:41 -0000 Received: (qmail 4458 invoked from network); 26 Mar 1999 13:54:53 -0000 Received: from post.thorcom.com (194.75.130.70) by magnet.plus.net.uk with SMTP; 26 Mar 1999 13:54:53 -0000 Content-Transfer-Encoding: 8bit Received: from troy.blacksheep.org ([194.75.183.50] ident=root) by post.thorcom.com with esmtp (Exim 2.04 #3) id 10QWxg-0005Ux-01; Fri, 26 Mar 1999 13:47:48 +0000 X-Priority: 3 Received: (from root@localhost) by troy.blacksheep.org (8.6.12/8.6.12) id NAA27981 for rsgb_lf_group-outgoing; Fri, 26 Mar 1999 13:47:56 GMT X-MSMail-Priority: Normal Received: from post.thorcom.com (root@post.unica.co.uk [194.75.183.70]) by troy.blacksheep.org (8.6.12/8.6.12) with ESMTP id NAA27863 for ; Fri, 26 Mar 1999 13:32:50 GMT From: drassew2@interalpha.co.uk X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from post.interalpha.co.uk ([195.26.224.18] helo=post.interalpha.net) by post.thorcom.com with esmtp (Exim 2.04 #3) id 10QWil-0005Ot-00 for rsgb_lf_group@blacksheep.org; Fri, 26 Mar 1999 13:32:23 +0000 Received: from th-mod20.interalpha.net (th-mod20.interalpha.net [195.26.228.211]) by post.interalpha.net (8.8.7/8.6.11) with SMTP id NAA12236 for ; Fri, 26 Mar 1999 13:32:20 GMT Date: Fri, 26 Mar 1999 13:32:20 GMT Message-ID: <199903261332.NAA12236@post.interalpha.net> X-Sender: drassew2@post.interalpha.co.uk X-Mailer: Windows Eudora Version 1.4.4 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed To: rsgb_lf_group@blacksheep.org Subject: Re: LF: 137 Carrier Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org >At 10:01 26/03/99 -0000, G3XDV wrote: >>On a similar subject, it would be really useful to be able to plot >>signal strength against time (say, 24 hours) using a computer - for >>simplicity it would help to use the sound card so that the same >>connection can be used as Spectrogram. For anyone who built the PIC based DSP interface (April 1997 RadCom) you have suitable recording hardware to hand. Just feed the AGC voltage conditioned to 0 - 5 Volts directly to the PIC input pin - disconnecting audio op amp buffering and audio gain of course. The OP amp could be used for the voltage conditioning but I'll that to individuals to sort out. An 8 bit word representing this voltage level is then sent along the RS232 port at 10 kHz or whatever sampling rate is set. I wrote some logging software for this (somewhere in the 'JNT archives) that reads the serial interface at prescribed intervals and logs the data to disc. This was actually done at the time for mains voltage monitoring but that's another story. If anyone is interested I'll look it out or write some more suitable logging software. With the advent of Gram and 56002EVM boards, this 8 bit interface is obsolete for DSP now but I supplied at least 40 pre-programmed PICs any many others requested the software to blow their own devices so a number must be lying around on shelves unused. With a PIC software modification, and changing the clock crystal to a 3.6864 MHz device it can be used for sampling at 7200 Hz for the VE2IQ BPSK software instead of the rather inelegant interface circuitry described - but I believe even this mode used the soundcard now! Andy G4JNT