Return-Path: X-Spam-DCC: paranoid 1102; 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=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, RATWARE_GECKO_BUILD,SPF_PASS 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 u2ILfkTA027709 for ; Fri, 18 Mar 2016 22:41:46 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ah26i-0008BE-AS for rs_out_1@blacksheep.org; Fri, 18 Mar 2016 21:38:56 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ah1dp-00074P-4j for rsgb_lf_group@blacksheep.org; Fri, 18 Mar 2016 21:09:05 +0000 Received: from mout01.posteo.de ([185.67.36.65]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.86) (envelope-from ) id 1age7b-0000yN-7I for rsgb_lf_group@blacksheep.org; Thu, 17 Mar 2016 20:02:15 +0000 Received: from dovecot03.posteo.de (dovecot03.posteo.de [172.16.0.13]) by mout01.posteo.de (Postfix) with ESMTPS id 97AB020A03 for ; Thu, 17 Mar 2016 21:02:14 +0100 (CET) Received: from mail.posteo.de (localhost [127.0.0.1]) by dovecot03.posteo.de (Postfix) with ESMTPSA id 3qQzlp3mN9z5vN7 for ; Thu, 17 Mar 2016 21:02:14 +0100 (CET) Message-ID: <56EB0D46.8010500@posteo.de> Date: Thu, 17 Mar 2016 21:02:14 +0100 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <56E526C8.5010401@abelian.org> <1536f9e8813-7821-7aea@webprd-m99.mail.aol.com> <56E5DCEF.4050905@abelian.org> <56E7090D.4090601@tiscali.co.uk> <56E7122E.1090907@abelian.org> <016f01d17e34$65318b80$2f94a280$@comcast.net> <56EAF20F.7050008@abelian.org> In-Reply-To: <56EAF20F.7050008@abelian.org> X-Scan-Signature: c1f72e5acb1277e013f90c915ad7ad68 Subject: Re: LF: EbNaut from Todmorden Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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 10.1.3.11 Status: O X-Status: X-Keywords: X-UID: 7402 Hi Paul, Am 17.03.2016 19:06, schrieb Paul Nicholson: > Also was inspired by something that Andy posted recently > about PAs powered from rectified mains. Somewhere in the shed > there's a mains isolating transformer and a nice variac. Same here, all my large PAs are using a H bridge switching at 320V directly. I can recommend the IRFP460A. Also my large PA from the VLF kite experiments were from that design. There is did not use a ferrite transformer. I took an isolated primary winding on the large coil, you remember. > > I've a vague recollection that someone on the list said that > you don't need an NoV for an earth antenna? Can anyone recall? It's Roger / G3XBM who should know more details. > I could run a wire for a km across the moors and terminate it > in a bog. There's an industrial audio amplifier in the shed > which is good for 4kW. Such a long earth loop would need > quite a high driving voltage. Also in the shed is a big toroidal > transformer, about 20cm diameter by 10cm thick, which might > make a hefty audio transformer if the material is up to it. Just try it, even if the results could be ppor. It's a big fun, you know. Remember my earth antenna in the forst :-) 73, Stefan