Skip to main content

Posts

Showing posts with the label Random Wire Antenna Lengths.

Random Wire Antenna Lengths. Post #1296

Random Wire Antenna Lengths (https://udel.edu/~mm/ham/radio/randomWire/ Author:  University of Delaware. Accessed on 30 October 2017, 2055 UTC, Post #1296. Comment: When you're on the trail, at the annual Field Day, or wherever a good antenna is unavailable, a random wire antenna "can save the day" if  you know its limitations.  This article does an excellent job of describing the theory, construction, and use of random wire antennas and the wire lengths you should avoid if you want an efficient, effective operation without excessive SWR. Of particular note is the series of graphs showing various wire lengths to avoid for different sets of amateur radio bands. The basic guidance is clear:  "The fewer bands, the fewer high impedance regions to avoid." According to the article, you want the wire antenna to be at least 1/4 wavelength long for each band you want to use.  For example, to work the 40 meter amateur radio band (7 mHz), make sure the antenna

Random Wire Antenna Lengths. Post #1088.

Random Wire Antenna Lengths (http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=30714). Author:  www.dxzone.com. Please click link or enter title URL into your browser search box to read the full article. Comment: A properly designed random wire antenna used in conjunction with a good ground radial or counterpoise system and a wide-range "tuner" can make an excellent HF multiband antenna for portable or emergency use. In this well-written article, we learn how to choose the optimal lengths for multiband operation.  The author supplies several helpful programs to get you started as well as excellent graphic presentations of the lengths you should avoid. The basic guidelines are simple: Make your random wire antenna at least 1/4 wavelength for each band you plan to use. Be sure to complete the antenna system with a ground radial or counterpoise system. Be prepared to use a wide-range antenna '"tuner" if you want multiband capability.  The anten

Simple Ham Radio Antennas--Random Wire Antenna Lengths. Post #781.

Random Wire Antenna Lengths (http://www.udel.edu/~mm/ham/randomWire/). Accessed on 21 May 2016, 06:33 hrs, UTC. Author:  The University of Delaware. Comment: A properly designed random wire antenna is a joy to use.  It's portable, inexpensive, and easy to store. However, there are a few design parameters that you must follow if you want to use random wire antennas.  This easily understood tutorial from The University of Delaware will give you the key design basics for this antenna. Among the topics discussed are:  The antenna lengths to avoid and the importance of using a ground radial or "counterpoise" system.  For best results, use at least a 1/4 wavelength antenna for each band you use.  An antenna transmatch (i.e. "tuner") and a ground radial system will keep rfi out of your shack and improve the efficiency of the random wire.  If you want multiband capability from 80 meters through 10 meters, consider using the original design from W3EDP.  This