Friday, October 17, 2014

Simple Ham Radio Antennas: A portable HF vertical antenna for 20 meters. Post #314.


.If you need an emergency or portable antenna for 20 meters, then this video by Dave (W0ZF) will get you on the air quickly and inexpensively. The only materials I had to buy were some nylon rope and a telescoping fiberglass fishing pole from the Hilo "Sports Authority" outlet. The pole cost me $30.00. I followed Dave's instructions and soon had a light weight portable antenna that performed well in a local beach park I used for testing. The vertical element should be a quarter wavelength for the 20 meter frequency of your choice. I chose 14.200 MHz and cut my vertical element and my radial wires to a length of 16.47 feet (16 feet, 5.6 inches)/5.02 meters. My coaxial feedline was 50 feet/15.24 meters of RG-8X coaxial cable with UHF connectors. I used a spare Budwig Hi-Que center coax connector to attach the antenna elements, with the + side connected to the vertical element and the - side connected to the ground radial system. My antenna wire and radials were some left over Radio Shack #18 AWG speaker wire. My radial system consisted of 12 quarter wave wires cut for 14.200 MHz. Performance of the antenna was quite good using a battery powered Ten-Tec Argosy II transceiver. I brought along my Drake MN-4 transmatch to take care of any SWR issues I ran into. Without the Drake MN-4 in the antenna system, my SWR measured 1.6 to 1 at my chosen frequency. The transmatch brought that down to 1:1 across the entire 20 meter band. I was pleasantly surprised how well this quickly made vertical antenna worked, considering the low power I was using (10 watts). So, if you need a cheap, efficient vertical antenna for 20 meters, try Dave's design. It works. For the latest Amateur Radio news and events, please check out the news feeds in the blog sidebars. These feeds are updated daily. Until next time, Aloha es 73 de Russ (KH6JRM).