Return-Path: Received: (qmail 28019 invoked from network); 16 Oct 2002 06:47:52 -0000 Content-Transfer-Encoding: 8bit Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 16 Oct 2002 06:47:52 -0000 X-MSMail-Priority: Normal Received: (qmail 947 invoked from network); 16 Oct 2002 06:47:08 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 16 Oct 2002 06:47:08 -0000 Received: from majordom by post.thorcom.com with local (Exim 4.10) id 181huV-00089L-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 16 Oct 2002 07:44:03 +0100 Received: from [194.243.74.245] (helo=tlvsca.vim.tlt.alcatel.it) by post.thorcom.com with esmtp (Exim 4.10) id 181huU-00089C-00 for rsgb_lf_group@blacksheep.org; Wed, 16 Oct 2002 07:44:02 +0100 Received: from tlvk7v (localhost [127.0.0.1]) by tlvsca.vim.tlt.alcatel.it (8.12.5/8.12.5) with SMTP id g9G6hSrt001982 for ; Wed, 16 Oct 2002 08:43:28 +0200 (MET DST) Date: Wed, 16 Oct 2002 08:23:30 +0100 From: "Claudio Girardi" To: rsgb_lf_group@blacksheep.org X-Mailer: Z-Mail Pro 6.2, NetManage Inc. [ZM62_16H] X-Priority: 3 Message-ID: MIME-Version: 1.0 Subject: LF: glfer 0.3.1 and non-linear signal processing Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed X-Spam-Status: No, hits=0.0 required=5.0tests=QUOTED_EMAIL_TEXT,SPAM_PHRASE_00_01version=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Dear LF Group, since I was curious to see the effect of the non-linear processing trick described by Alex and of limiting the input signal, I implemented them in glfer and released version 0.3.1; as usual you can find the sources at http://www.qsl.net/in3otd/glfer.html . The FFT routine has now a selectable non-linear processing option, according to the formula given by Alex and also a selectable "Hendrixizer", which uses the 10th radix of the normalized input signal as a limiting function. I did some quick test yesterday evening, but there were no QRSS signals (hi) so I used some weak CW signals on the 20 m band; as noted by Jim, the two non-linear processing options are in some way related, since the spectra they produce are somewhat similar, but certainly more testing with real LF signals is needed... As a last note, this release should correct also the dependencies on the fftw library, a bug which prevented compilation on systems without this library installed... Happy experimenting with non-linear processing! 73 de Claudio, IN3OTD -- Home Page: http://www.qsl.net/in3otd/ Alex wrote: [snip] > So it is very simple to realize! The only addition is input convertion > of the incoming signal > > S1(t) = S(t)/[A + S(t)*S(t)] > > where S(t) if signal from RX. Parameter A shold be controlled to get > best reciption. Than signal S1(t) is processed by conventional procedure > (say FFT). Jim wrote: [snip] > Well, now all I have to do is sit back and relax while the spectrogram > software guys get it working... :-)