Return-Path: Received: (qmail 23225 invoked from network); 23 Apr 2003 18:09:29 -0000 Received: from marstons.services.quay.plus.net (212.159.14.223) by mailstore with SMTP; 23 Apr 2003 18:09:29 -0000 Received: (qmail 14217 invoked by uid 10001); 23 Apr 2003 18:09:29 -0000 Received: from post.thorcom.com (193.82.116.70) by marstons.services.quay.plus.net with SMTP; 23 Apr 2003 18:09:29 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.14) id 198Ofw-0008Af-FH for rsgb_lf_group-outgoing@blacksheep.org; Wed, 23 Apr 2003 19:08:56 +0100 Received: from [62.253.164.42] (helo=mta2-svc.business.ntl.com) by post.thorcom.com with esmtp (Exim 4.14) id 198Ofq-0008AW-Le for rsgb_lf_group@blacksheep.org; Wed, 23 Apr 2003 19:08:50 +0100 Received: from l8p8y6 ([62.252.228.30]) by mta2-svc.business.ntl.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with SMTP id <20030423180849.NKOK1184.mta2-svc.business.ntl.com@l8p8y6> for ; Wed, 23 Apr 2003 19:08:49 +0100 Message-ID: <006901c309ba$f3ed7b60$c0e4fc3e@l8p8y6> From: "hamilton mal" To: rsgb_lf_group@blacksheep.org References: <01C309A5.34411480.g4jnt@thersgb.net> Date: Wed, 23 Apr 2003 18:08:00 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Re: Amidon Cores (slightly diverging from topic) Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=-13.5 required=5.0tests=ORIGINAL_MESSAGE,QUOTED_EMAIL_TEXT,QUOTE_TWICE_1,REFERENCESversion=2.53 X-Spam-Checker-Version: SpamAssassin 2.53 (1.174.2.15-2003-03-30-exp) X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false ----- Original Message ----- From: "Andy talbot" To: "Rsgb_Lf_Group (E-mail)" Sent: Wednesday, April 23, 2003 2:32 PM Subject: LF: Amidon Cores (slightly diverging from topic) > Does anyone know of a UK supplier of Amidon iron dust cores - they may be > called American Cores & Electronics now, according to the Amidon web page. The > web is not too helpful at finding a UK stockist though. > I need a lot of them for a (work based) design with many parallel channels of > filtering, and for various bureaucratic reasons to do with importation, need > to get them from a UK supplier. > > btw. I've discovered the published Al values for these, particularly for the > T2 material (2 - 30MHz) is some way out from that shown in the ARRL handbook. > Measured discrepancies of 10% to 30% seem to be common, so every coil has to > be wound and measured to get to spec This is normal procedure, published figures are usually a rough guide because of variations in core material etc. Like all the other measurements about radiated power from transmitters they can vary by up to 20 db as discussed in previous messages posted here over the years. It is impossible to calculate whether the person is emitting 1w or 10w All guess work, you must have seen some of these discussions, after several pages of formulae the conclusion are that these calculation are within 10 db or so. ie could be 1w or 10w erp. Never believe anything you hear or see!!!!!!!!! Too many pretentious experts not surprisingly from the South, and often adamant that they are right!!!!!!!! Fortunately north of Watford, especially Scotland and Ireland we do not fall for this. G3KEV > > Andy G4JNT >