Return-Path: Received: (qmail 17190 invoked from network); 3 Jun 2000 05:48:26 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by teachers.core.plus.net.uk with SMTP; 3 Jun 2000 05:48:26 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12y6iB-0005Ep-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 03 Jun 2000 06:43:07 +0100 Received: from teapot25.domain0.bigpond.com ([139.134.5.173]) by post.thorcom.com with smtp (Exim 3.02 #1) id 12y6i9-0005Ek-00 for rsgb_lf_group@blacksheep.org; Sat, 03 Jun 2000 06:43:06 +0100 Received: from localhost (localhost [127.0.0.1]) by teapot25.domain0.bigpond.com (NTMail 3.02.13) with ESMTP id ta522905 for ; Sat, 3 Jun 2000 15:37:48 +1000 Received: from MOIP-A-003-pool-167.tmns.net.au ([139.134.91.167]) by mail0.bigpond.com (Claudes-Hot-MailRouter V2.7e 13/1747428); 03 Jun 2000 15:37:47 Message-ID: <000d01bfcd1e$0f429d00$a75b868b@zimslaptop> From: "Graeme Zimmer" To: rsgb_lf_group@blacksheep.org, vernall@xtra.co.nz References: <393881DE.3D9D@xtra.co.nz> Subject: LF: Re: Bessel bandpass filter? Date: Sat, 3 Jun 2000 15:39:15 +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 5.00.2919.6600 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: Hi Bob, > But the intended thrust of this email is to ask about if anyone can find > a reference to a BESSEL BANDPASS filter. "Electronic Filter Design Handbook" by Williams and Taylor has a section on "Capacitive Coupled Resonant" bandpass filters. (These are the kind where a number of parallel tuned circuits are coupled together via capacitors) The book offers a table for Bessel parameters. It does a design for "constant delay over passband" bandpass using the Bessel tables... Let me know if you could use a photocopy of a few pages..... ......................... Zim ............. VK3GJZ