X-GM-THRID: 1238798748720296233 X-Gmail-Labels: rsgb lf Delivered-To: daveyxm@gmail.com Received: by 10.78.172.11 with SMTP id u11cs268662hue; Sat, 9 Jun 2007 10:35:50 -0700 (PDT) Received: by 10.82.182.1 with SMTP id e1mr7517420buf.1181410550778; Sat, 09 Jun 2007 10:35:50 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id i8si3828784nfh.2007.06.09.10.35.47; Sat, 09 Jun 2007 10:35:50 -0700 (PDT) Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) DomainKey-Status: bad (test mode) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Hx4ns-0006ue-KG for rs_out_1@blacksheep.org; Sat, 09 Jun 2007 18:32:44 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Hx4ns-0006uV-59 for rsgb_lf_group@blacksheep.org; Sat, 09 Jun 2007 18:32:44 +0100 Received: from wx-out-0506.google.com ([66.249.82.236]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Hx4nr-0005Mi-3r for rsgb_lf_group@blacksheep.org; Sat, 09 Jun 2007 18:32:44 +0100 Received: by wx-out-0506.google.com with SMTP id h26so969119wxd for ; Sat, 09 Jun 2007 10:32:42 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=googlemail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:mime-version:content-type; b=rd9K64CFyFh4ceEnCaDbLdT+UMWpZfSzLhpXmE3hIcfPIarRQ6/ARA0RXGMQYyti6NDUvb82vFCpyiJQevNdtvcv1Oc2zFw987hnDBxb6t9zVM6xWAJV4gzIcsNUb/2aXe0sSqXYPganWz+LrM3UBQ5XhXar1RVrLAuJ0rKd+p4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=beta; h=received:message-id:date:from:to:subject:cc:mime-version:content-type; b=EfXFS6PUoTT6d5NVh1sCR3OeI+C0IllEU4++pKpHStyBn7IYErnJbpO8YgdMJk9vVvyTvzgDh0wjbSNtssz/vlTfIvsVbpFa4cRi4345BQGiGcfZfRHFICuNW+L50z55lUfQrfQoCwzPwI8lYEuluTteTfdpX+bVvuAa8f0VajM= Received: by 10.90.96.7 with SMTP id t7mr3979747agb.1181410361938; Sat, 09 Jun 2007 10:32:41 -0700 (PDT) Received: by 10.90.50.7 with HTTP; Sat, 9 Jun 2007 10:32:41 -0700 (PDT) Message-ID: Date: Sat, 9 Jun 2007 18:32:41 +0100 From: "Andy Talbot" To: rsgb_lf_group@blacksheep.org Cc: "Linda Holtby" MIME-Version: 1.0 DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: MF Still on shifp? Content-Type: multipart/alternative; boundary="----=_Part_75556_5210471.1181410361919" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=HTML_MESSAGE autolearn=no version=2.63 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 Status: O X-Status: X-Keywords: X-UID: 1365 ------=_Part_75556_5210471.1181410361919 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Yesterday I was watching two large cruise ships sail down Southampton water (P&O ships, 'Artemis' and 'Aurora'). Both had a large wire antennas strung between the masts, and in the case of Artemis this extended down at each end close to bow and stern; and there may even have been two wire side-by-side on this ship. A really long antenna. I'm not sure of the length of these ships, but they could be 200 metres (ish), so even at the bottom end of HF these are electrically long-wires. Of course, the pair on Artemis, if I saw them correctly, could even be phased for really high gain at HF - a Rhombic perhaps? Does anyone know if large modern ships still have MF, or a serious HF presence? Or are the wire antenna(s ?) just there to hang flags from? Or are they not even antennas, but just used for supporting decorations. Artemis also had a mass of big whips on the bow, which I assume were base tuned HF - the normal VHF whips were practically invisible beside them. Aurora presumably had something similar, but they weren't obvious. Needless to say, each ship had two large VSAT radomes, and three or four smaller Inmarsat (and other satcom?) antennas. Andy G4JNT ------=_Part_75556_5210471.1181410361919 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline
Yesterday I was watching two large cruise ships sail down Southampton water (P&O ships,  'Artemis' and 'Aurora').   Both had a large wire antennas strung between the masts, and in the case of  Artemis this extended down at each end close to bow and stern; and there may even have been two wire side-by-side on this ship.  A really long antenna.   I'm not sure of the length of these ships, but they could  be 200 metres (ish), so even at the bottom end of HF these are electrically long-wires.   
Of course, the pair on Artemis, if I saw them correctly, could even be phased for really high gain at HF - a Rhombic perhaps?
 
Does anyone know if large modern ships still have MF, or a serious HF presence?  Or are the wire antenna(s ?) just there to hang flags from?  Or are they not even antennas, but just used for supporting decorations.
 
Artemis also had a mass of big whips on the bow, which I assume were base tuned HF - the normal VHF whips were practically invisible beside them.   Aurora presumably had something similar, but they weren't obvious.
 
Needless to say, each ship had two large VSAT radomes, and three or four smaller Inmarsat (and other satcom?) antennas.
 
Andy  G4JNT
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