Return-Path: Received: (qmail 18537 invoked from network); 9 Jan 2002 21:41:08 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 9 Jan 2002 21:41:08 -0000 Received: (qmail 7549 invoked from network); 9 Jan 2002 21:41:07 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 9 Jan 2002 21:41:07 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16OQRM-0003c1-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 09 Jan 2002 21:39:20 +0000 Received: from rhenium.btinternet.com ([194.73.73.93] helo=rhenium) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16OQRL-0003bw-00 for rsgb_lf_group@blacksheep.org; Wed, 09 Jan 2002 21:39:20 +0000 Received: from host213-1-187-178.btinternet.com ([213.1.187.178] helo=presario-1920) by rhenium with smtp (Exim 3.22 #8) id 16OQQa-0003Nb-00 for rsgb_lf_group@blacksheep.org; Wed, 09 Jan 2002 21:38:32 +0000 From: "John W Gould" To: "Rsgb_Lf_Group@Blacksheep.Org" Subject: LF: Inductive RFID transmit spectrum Date: Wed, 9 Jan 2002 21:39:56 -0000 Message-ID: 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 IMO, Build 9.0.2416 (9.0.2910.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Importance: Normal Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Inductive RFIDs that operate at 134.8kHz pose a possible treat in the future to the noise floor in the 136kHz amateur band. A paper is currently being considered internationally that would allow an increase in the modulation sidebands, falling in the 136kHz band and elsewhere, from the RFID system. One item of detail omitted from the papers that are being reviewed is a precise specification of the transmit spectrum from the RFID "readers" as the interrogators are termed. It is assumed that it is a flat spectrum with constant spectral density. Grateful if anyone can provide me with more detail of the system's modulation scheme / transmit spectrum. 73 John, G3WKL RSGB HF Committee g3wkl@btinternet.com