Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_MED,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: : mailn 1480; Body=3 Fuz1=3 Fuz2=3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id v6OMtIPZ020924 for ; Tue, 25 Jul 2017 00:55:19 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dZmAm-0004fF-G9 for rs_out_1@blacksheep.org; Mon, 24 Jul 2017 23:49:56 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dZmAg-0004f6-5Y for rsgb_lf_group@blacksheep.org; Mon, 24 Jul 2017 23:49:50 +0100 Received: from smtp3web.tin.it ([212.216.176.237]) by relay1.thorcom.net with esmtp (Exim 4.89) (envelope-from ) id 1dZmAd-0000Hm-24 for rsgb_lf_group@blacksheep.org; Mon, 24 Jul 2017 23:49:48 +0100 Received: from feu5 (10.192.64.15) by smtp3web.tin.it (8.6.060.43) id 583FEE8C0408C484 for rsgb_lf_group@blacksheep.org; Tue, 25 Jul 2017 00:49:45 +0200 Received: from (87.15.170.245) by wmlighttin.pc.tim.it; Tue, 25 Jul 2017 00:49:45 +0200 Message-ID: <15d76cac1c1.marcocadeddu@tin.it> Date: Tue, 25 Jul 2017 00:49:45 +0200 (CEST) From: "marcocadeddu@tin.it" To: Mime-Version: 1.0 X-Originating-IP: 87.15.170.245 X-Scan-Signature: 8ef270cc2ec30cd34b6313d7ada17a45 Subject: R: Re: LF: Re: Antenna change over relay question Content-Type: text/plain;charset="UTF-8" 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 2.75 Status: RO X-Status: X-Keywords: X-UID: 12291 Hello LF & VLF, I posted my solution, but the attached picture of my ATU for LF/MF was too much for blacksheep.. In my ATU I have to switch in and out the LF base coil of my antenna and change the matching transformer for LF and MF. I made it with 2 vacuum relays: the switching of XFMR is made with a Siemens VR311 (rated at 10kV 20A) the coil switching is made with a Jennings RE6 which is rated at 25kV 25A. Both are of course surplus purchases.. but are easy to find on e-bay. For new relays purchase, don't forget, if still valid, that Kilovac was used to sell a small number of relays each year to HAM operators with special (affordable.. ) price: if you wish to have brand new units a check on their web pages is worth ;-) 73 Marco IK1HSS ----Messaggio originale---- Da: andy.g4jnt@gmail.com Data: 24-lug-2017 17.40 A: Ogg: Re: LF: Re: Antenna change over relay question Digressing slightly, but a parallel warning... I once hot disconnected a BNC plug carrying 700 Watts of RF (Low Z, transmitter output) . As the contact broke it generated a plasma arc that shot out of the BNC plug that I dropped in shock. It continued to burn, vaporising the centre pin of the BNC, and burning a mark into the floor surface I'd dropped it onto. 'jnt On 24 July 2017 at 15:58, Chris Wilson wrote: > Hello Ian, > > You have me worried now, as does Andy with his last post, the thought > of putting a kilowatt into the RX antenna socket of my 590 is not a > pleasant or cheap one... Hmmm. > > > > Monday, July 24, 2017, 3:40:38 PM, you wrote: > > > Hi Chris/Stefan > > > Loosely connected to your question, I wanted to switch my Inv L between > > LF/MF Variometer/loading coils and HF Auto remote tuner remotely, i. e > 120' > > away from the shack. > > > Every relay I tried had insulation break down and contact arc over. Only > > running 360 W at MF and 300 at LF. > > > My solution was to fabricate a 3 position Knife type switch operated via > a > > Servo motor to switch the antennae and a standard 20 Amp Rated relay for > the > > RF inputs to the Tuner and Variometers. > > > No more insulation break down or arc over. The contacts are mounted on > Old > > Eddystone porcelain insulators. > > > I would be interested to know how the relay holds up with 1 kW at 136 > kHz. > > > 73 > > > Ian G4GIR > > > > > > > -- > Best regards, > Chris mailto:dead.fets@gmail.com > > >