Return-Path: X-Spam-DCC: paranoid 1170; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_RCVD_HELO,SUBJ_RE_NUM autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id t9K9Tvwc031316 for ; Tue, 20 Oct 2015 11:29:57 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZoTBn-0003C8-1P for rs_out_1@blacksheep.org; Tue, 20 Oct 2015 10:26:39 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZoTBm-0003Bz-Nf for rsgb_lf_group@blacksheep.org; Tue, 20 Oct 2015 10:26:38 +0100 Received: from smarthost01b.mail.zen.net.uk ([212.23.1.3]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1ZoTAi-0004aG-Dy for rsgb_lf_group@blacksheep.org; Tue, 20 Oct 2015 10:26:37 +0100 Received: from [82.70.254.222] (helo=OfficeWin7.lan) by smarthost01b.mail.zen.net.uk with esmtp (Exim 4.80) (envelope-from ) id 1ZoTAS-000FdF-CC for rsgb_lf_group@blacksheep.org; Tue, 20 Oct 2015 09:25:16 +0000 Date: Tue, 20 Oct 2015 10:25:16 +0100 From: Chris Wilson Organization: Gatesgarth Developments X-Priority: 3 (Normal) Message-ID: <174420693.20151020102516@chriswilson.tv> To: John Rabson In-Reply-To: References: <1435044716.20151018182802@chriswilson.tv> MIME-Version: 1.0 X-Originating-smarthost01b-IP: [82.70.254.222] X-Scan-Signature: c0336009bd9bab526ca27d297ea7579a Subject: Re[2]: LF: Where to measure antenna current? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 4543 Hello John, Monday, October 19, 2015 Thanks John, yes it does help, much appreciated, but what I am still unsure of is if my Scopematch, that shows voltage and current waveforms, is also, on the current waveform, displaying antenna current? Does it not "do the same job" as a current meter? With apologies to Kev, who has never heard of anyone with so many LF issues ;) I have had to run half power recently, as full power is tripping the house RCD after a minute or so of transmitting. I am ordering some FT-240-77 material toroids, and building an isolation matching transformer, instead of the auto transforming coil, in the hope it cures this domestically disharmonious issue! I also have a two piece E core to try. The fact it also triggers the workshop alrm is not so big a deal as I can at least turn it off when transmitting. Has anyone else had issues with RCD's and LF? Thanks again. > Chris, > The arrangement I have here comprises a 5A FSD RF ammeter between > the transmitter and the antenna isolating transformer, and another > such ammeter (switchable between 5A and 500mA FSD) between the > isolating transformer and the earthy end of the antenna matching > network.. The intended impedance at this point is 50 ohms. > Hope this helps, John -- Best regards, Chris mailto:chris@chriswilson.tv