From owner-qrp-l@Lehigh.EDU Wed Apr 2 12:56:30 1997 Received: from fidoii.CC.Lehigh.EDU (fidoii.CC.Lehigh.EDU [128.180.1.4]) by oucsace.cs.ohiou.edu (8.8.5/8.8.5) with ESMTP id MAA18686 for ; Wed, 2 Apr 1997 12:56:28 -0500 (EST) Received: from Lehigh.EDU ([127.0.0.1]) by fidoii.cc.lehigh.edu with SMTP id <35185-29309>; Wed, 2 Apr 1997 12:53:18 -0500 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <35171-29309>; Wed, 2 Apr 1997 12:51:48 -0500 Received: from x9.boston.juno.com (x9.boston.juno.com [205.231.100.25]) by nss2.CC.Lehigh.EDU (8.8.5/8.8.5) with ESMTP id MAA68208 for ; Wed, 2 Apr 1997 12:51:42 -0500 Received: (from wa5whn@juno.com) by x9.boston.juno.com (queuemail) id M^Z10791; Wed, 02 Apr 1997 12:49:37 EST Message-Id: <19970402.110032.4559.2.wa5whn@juno.com> Date: Wed, 02 Apr 1997 12:49:37 EST Reply-To: wa5whn@juno.com Sender: owner-qrp-l@Lehigh.EDU Precedence: bulk From: wa5whn@juno.com (Jay D Miller) To: "Low Power Amateur Radio Discussion" Subject: Old Antenna Trick, from many years ago, applied to the WARC bands X-Mailer: Juno 1.15 X-Juno-Line-Breaks: 0-2,23-24,27-28,33-34,46-51 X-Listprocessor-Version: 8.1 beta -- ListProcessor(tm) by CREN Status: RO QRP-Lers, If You have access to 300 ohm ribbon twin lead, cut one-half of the dipole for 30 meters (one side of the ribbon cable, one ribbon cable can make 2 dipoles), then the bottom half part of the twin lead for 20 meters, that way, You have a 300 ohm ribbon twin lead, with the top part of the ribbon cable, cut for 30 meters (1/2 wave) & the bottom half for 20 meters (1/2 wave). I had made up another one, for 17 & 15 meters. They are feed, at the center, with RG-174, no traps, no tuners, and they roll up nicely into my back pack with either my Sierra (N6KR design) or GM-30/20/17/15 combo (NN1G design). The idea for this is from "The ARRL Antenna Book", 14th edition, 1982, page 8-3. I was looking for light weight antennas, for hiking around in the Mountains. For example, You could build (I have not done this combo yet) a 40/30 meter dipole with 300 ohm ribbon twin lead, where the upper part of the ribbon cable (top wire) is cut for 40 meters & the bottom half (bottom wire) is cut for 30 meters. You will find using the old 468/Freq. (MHz) will make this dual combination a bit long, but You can prune it. If none of this makes any sense, I can upload a few *.JPG files on to the W5BI web page, and show You what I am talking about. Essentially, You take 300 ohm ribbon twin lead, trim the top wire part of the cable for 40 meters, the bottom part of the cable for 30 meters. It becomes a dual band (resonant) antenna, light weight. All fed with one feed line, tied to 3 insulators. What You have is a dual band antenna, using 3 insulators, fed with one piece of coax, in the center. In this case, RG-174 for QRP purposes. RG-58 for QRP & QRO purposes. Anyone want to build a WIMPs antenna, using this method ? 30 meters on the top wire of the 300 ohm ribbon cable (1/2 wave dipole), with 17 meters on the bottom wire, of the 300 ohm ribbon cable ? Fed in the center with RG-58 or RG-174.This same technique works well with 450 ohm ladder line too. How many days until QRPTTF (April 26th) ? (22) We (W5BI, WB5LYJ , WA5WHN & possibly K5JS) will be live, overlooking one of the (alledged) Corona, NM debris Fields, "near" the following coordinates, Lat. 33 degrees 56.575 minutes N, Long. 105 degrees 17.821 minutes W. A word to the wise, street vehicles will fail miserably in this terrain, and these are trails, not roads, plus they are unmarked. This is the middle of no where (desert). W5BI's 4WD pickup has 16" of ground clearance, I have 15" of ground clearance, in my 4WD vehicle (Measured from the differential, on level ground). We have access to the Capitan Repeater (146.61 MHz, W5YFN). 360 degrees of viewing the desert, except for the El Capitan Mountains, 22 miles to the south of us. Where is everyone else going to be for QRPTTF ? 72...Jay, WA5WHN DM65qd From owner-qrp-l@Lehigh.EDU Wed Apr 2 13:37:37 1997 Received: from fidoii.CC.Lehigh.EDU (fidoii.CC.Lehigh.EDU [128.180.1.4]) by oucsace.cs.ohiou.edu (8.8.5/8.8.5) with ESMTP id NAA21085 for ; Wed, 2 Apr 1997 13:37:36 -0500 (EST) Received: from Lehigh.EDU ([127.0.0.1]) by fidoii.cc.lehigh.edu with SMTP id <34986-36988>; Wed, 2 Apr 1997 13:36:38 -0500 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <34854-15994>; Wed, 2 Apr 1997 13:34:17 -0500 Received: from krypton.nmr.Hawaii.Edu (krypton.nmr.Hawaii.Edu [128.171.55.13]) by nss2.CC.Lehigh.EDU (8.8.5/8.8.5) with SMTP id NAA04326 for ; Wed, 2 Apr 1997 13:34:00 -0500 Received: by krypton.nmr.Hawaii.Edu (4.1/SMI-4.1) id AA15098; Wed, 2 Apr 97 08:33:36 HST Message-Id: <9704021833.AA15098@krypton.nmr.Hawaii.Edu> Date: Wed, 2 Apr 97 08:33:36 HST Reply-To: mike@krypton.nmr.Hawaii.Edu Sender: owner-qrp-l@Lehigh.EDU Precedence: bulk From: mike@krypton.nmr.Hawaii.Edu (Mike W. Burger) To: "Low Power Amateur Radio Discussion" Subject: twin lead two band dipoles X-Listprocessor-Version: 8.1 beta -- ListProcessor(tm) by CREN Status: RO When cutting for a portable twin lead dipole as described, by making it into a pair of parallel dipoles cut for two frequencies, first cut both wires carefully off the end of the twin lead you are going to use for the dipole elements. You can end up with about two inches of the center web material sticking out the end. This can be used as an insulator by just punching a hole and tying on nylon fishing line. This way you do not even need end insulators, and a bit of cleverness can even eliminate the center insulator. From owner-qrp-l@Lehigh.EDU Wed Apr 2 13:46:25 1997 Received: from fidoii.CC.Lehigh.EDU (fidoii.CC.Lehigh.EDU [128.180.1.4]) by oucsace.cs.ohiou.edu (8.8.5/8.8.5) with ESMTP id NAA21830 for ; Wed, 2 Apr 1997 13:46:24 -0500 (EST) Received: from Lehigh.EDU ([127.0.0.1]) by fidoii.cc.lehigh.edu with SMTP id <34860-36988> convert rfc822-to-8bit; Wed, 2 Apr 1997 13:40:50 -0500 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <34891-15994>; Wed, 2 Apr 1997 13:38:42 -0500 Received: from SMTP.USIT.NET (root@smtp.usit.net [199.1.48.16]) by nss2.CC.Lehigh.EDU (8.8.5/8.8.5) with ESMTP id NAA117967 for ; Wed, 2 Apr 1997 13:38:35 -0500 Received: from jackson-max117.dynamic.usit.net (jackson-max117.dynamic.usit.net [204.194.175.246]) by SMTP.USIT.NET (8.7.5/8.6.12) with SMTP id NAA27771 for ; Wed, 2 Apr 1997 13:38:32 -0500 (EST) Message-Id: <3344a63f.2874780@smtp.usit.net> Date: Wed, 02 Apr 1997 18:38:18 GMT Reply-To: mdwatt@usit.net Sender: owner-qrp-l@Lehigh.EDU Precedence: bulk From: mdwatt@usit.net (Marty Watt) To: "Low Power Amateur Radio Discussion" Subject: Re: Old Antenna Trick, from many years ago, applied to the WARC bands In-Reply-To: <19970402.110032.4559.2.wa5whn@juno.com> References: <19970402.110032.4559.2.wa5whn@juno.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT X-To: "Low Power Amateur Radio Discussion" X-Mailer: Forte Agent 1.0/32.390 X-Listprocessor-Version: 8.1 beta -- ListProcessor(tm) by CREN Status: RO On Wed, 02 Apr 1997 12:49:37 EST, wa5whn@juno.com (Jay D Miller) wrote: >QRP-Lers, > > > If You have access to 300 ohm ribbon twin lead, cut one-half of the >dipole for 30 meters (one side of the ribbon cable, one ribbon cable can >make 2 dipoles), then the bottom half part of the twin lead for 20 >meters, that way, You have a 300 ohm ribbon twin lead, with the top part >of the ribbon cable, cut for 30 meters (1/2 wave) & the bottom half for >20 meters (1/2 wave). I had made up another one, for 17 & 15 meters. They >are feed, at the center, with RG-174, no traps, no tuners, and they roll >up nicely into my back pack with either my Sierra (N6KR design) or >GM-30/20/17/15 combo (NN1G design). The idea for this is from "The ARRL >Antenna Book", 14th edition, 1982, page 8-3. I was looking for light >weight antennas, for hiking around in the Mountains. For example, You >could build (I have not done this combo yet) a 40/30 meter dipole with >300 ohm ribbon twin lead, where the upper part of the ribbon cable (top >wire) is cut for 40 meters & the bottom half (bottom wire) is cut for 30 >meters. You will find using the old 468/Freq. (MHz) will make this dual >combination a bit long, but You can prune it. If none of this makes any >sense, I can upload a few *.JPG files on to the W5BI web page, and show >You what I am talking about. Essentially, You take 300 ohm ribbon twin >lead, trim the top wire part of the cable for 40 meters, the bottom part >of the cable for 30 meters. It becomes a dual band (resonant) antenna, >light weight. All fed with one feed line, tied to 3 insulators. > > What You have is a dual band antenna, using 3 insulators, fed with one >piece of coax, in the center. In this case, RG-174 for QRP purposes. >RG-58 for QRP & QRO purposes. I did this with 450 ohm ladder line -- for 40/30, it took 56.5 ft. total, cut as follows: |cut here _______________________ ___________________ 40m - 33 ft. 30m - 23.5 ft. _______________ ___________________________ 30m - 23.5 ft. |cut here 40m - 33 ft. Cut the space between the wires (9.5 ft), and trim to resonance. This uses the 468/f formula, and works out a bit long, so you have room to trim. Might want to add 6" or so, if you are unsure. 72 es 73 de Marty, KM7W __________________________________________________________________ Jackson, Tennessee e-mail: mdwatt@usit.net http://www.public.usit.net/mdwatt "The Curmudgeon's Corner" NorCal #???? - ARCI #7514 - QRP-L #953 - AK/QRP #098 - Grid EM55oq ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~