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## RE: [TowerTalk] Dipole Problem

 To: , RE: [TowerTalk] Dipole Problem "Tod - ID" Wed, 18 Feb 2004 20:32:58 -0700
 ```The resistive part of the impedance of the dipole is a function of its height above ground. The ARRL Antenna Book and Handbook cover this. The center of your antenna is significantly lower than 1/2 wavelength above ground and will be less than 73 ohms. I am not sure why you are reading VSWR = 2.3:1 because I would expect a pure resistance of 29 ohms to give a VSWR = 1.7:1 .Perhaps you have some Broadcast signal adding to the signal being read by the analyzer. However, as long as you can feed power from the transmitter into the feed line it will not make a noticeable difference to the folks you are working. The antenna tuner or the transceiver antenna (feed line) matching unit will assure that the power goes into the feed line and off to the center of the antenna for radiating to the people you wish to work. Tod, KØTO -----Original Message----- From: towertalk-bounces@contesting.com [mailto:towertalk-bounces@contesting.com] On Behalf Of K6TFZ@aol.com Sent: Wednesday, February 18, 2004 3:18 PM To: towertalk@contesting.com Subject: [TowerTalk] Dipole Problem I always thought a dipole was simple. First the description: 75 meter dipole (58.5 feet per leg) placed 4 feet above peak of second story roof. Roof is 40 feet wide so ran extra wire at right angle outward toward rest of house (big square "U"). Center of dipole is in center of 40 foot section using a large egg insulator and an SO-239 to start, balun later. My AEA-HF and Autek RF-1 both read resonance at 3968 KHz which is fine BUT SWR is about 2.3:1, R=29 ohms. The only thing I can figure is the way I wrapped the wire on the egg insulator: so that if the insulator were to break, the wires would catch each other and not part. Could there be that much capacitance there to throw my reading off that much? The wires are at right angles to each other. Any other suggestions? TIA. Geoff, K6TFZ _______________________________________________ See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA. _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk _______________________________________________ See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA. _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
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