Return-Path: Received: (qmail 8085 invoked from network); 2 Oct 1999 00:44:49 +0100 Received: from unknown (HELO magnet.force9.net) (195.166.128.26) by guiness.force9.net with SMTP; 2 Oct 1999 00:44:49 +0100 Received: (qmail 31137 invoked from network); 1 Oct 1999 23:50:29 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by magnet.plus.net.uk with SMTP; 1 Oct 1999 23:50:29 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 11XCC0-0007r3-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 02 Oct 1999 00:34:24 +0100 Received: from teapot29.domain7.bigpond.com ([139.134.5.236]) by post.thorcom.com with smtp (Exim 3.02 #1) id 11XCBy-0007qy-00 for rsgb_lf_group@blacksheep.org; Sat, 02 Oct 1999 00:34:23 +0100 Received: from localhost (localhost [127.0.0.1]) by teapot29.domain7.bigpond.com (NTMail 3.02.13) with ESMTP id na000715 for ; Sat, 2 Oct 1999 09:31:34 +1000 Received: from MOIP-A-003-pool-178.tmns.net.au ([139.134.91.178]) by mail7.bigpond.com (Claudes-Particular-MailRouter V2.5 15/3290966); 02 Oct 1999 09:31:34 Message-ID: <003201bf0c65$76cdeb20$b25b868b@zimslaptop> From: "Graeme Zimmer" To: rsgb_lf_group@blacksheep.org References: <004801bf0c5b$78aca1c0$23088cd4@default> Subject: LF: Re: re Dave's Comment on filters Date: Sat, 2 Oct 1999 09:34:10 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Dear Alan, > I can hear, and copy, most of the signals on 136 with a 2.5KHz SSB filter, > ................ > carrier of DCF39 is only 60dB down, and I get a light trace of the signal on > the waterfall display. I have been "listening" to the NewZealanders on 181.4 Khz for a few months now (is about 2500 km toVK) and find that Spectrogram is much happier if I use my wide SSB filter. If I use my narrow CW filter it rings badly to the everpresent QRN. This ringing is very visible on Spectrogram. I am looking for a definitive article or text which explains which is the best FILTER TYPE (shape, phase response, inpulse response, etc) to minimise ringing from QRN. Can any body help please? regards .............. Zim .............. VK3GJZ