Return-Path: Received: (qmail 26781 invoked from network); 3 Jun 2000 21:25:15 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by bells.core.plus.net.uk with SMTP; 3 Jun 2000 21:25:15 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12yLJb-0008N1-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 03 Jun 2000 22:18:43 +0100 Received: from mta1-rme.xtra.co.nz ([203.96.92.1]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 12yLJZ-0008Mj-00 for rsgb_lf_group@blacksheep.org; Sat, 03 Jun 2000 22:18:42 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from [202.27.178.186] by mta1-rme.xtra.co.nz (InterMail vM.4.01.02.17 201-229-119) with SMTP id <20000603211803.ZSKV5139981.mta1-rme.xtra.co.nz@[202.27.178.186]> for ; Sun, 4 Jun 2000 09:18:03 +1200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <39396E01.5A2C@xtra.co.nz> Date: Sun, 04 Jun 2000 08:43:45 +1200 From: "vernall" X-Mailer: Mozilla 3.01C-XTRA (Win95; I) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Re: Bessel bandpass filter? References: <001401bfcd2f$d96512a0$095b868b@zimslaptop> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Graeme Zimmer wrote: > > 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 My first reply was direct to Zim, but I should also acknowledge it to reflector reader: I would like a copy, thanks for the offer Zim. I'm intending to build an active filter equivalent, where each stage is practically independent of others, which is different to the mutually coupled passive filter, but the design info would be interesting in its own right. 73, Bob