Monday, October 13, 2014

Simple Ham Radio Antennas: The 10 minute dipole. Post #313


This is what I call a "quick and dirty" dipole antenna suitable for field expedient use or for portable operation. This video by Ten-Tec's Scott Robbins (W4PA) has received a bit of criticism, but its basic premise is excellent: "Cut, solder, and tie off." Since I'm a bit slow in the soldering department (far sightedness doesn't help much in close work...I had to use my bifocals on this project), I just took my time and built Scott's basic model in about a half-hour. I cut the antenna for the mid-point of the 40 meter band (7.150 MHz) and used some extra RG-8X coax as the feedline. Fortunately, I had two well-placed Norfolk Pine Trees on my property and was able to get the dipole about 40 ft/12.19 meters above ground. I made a choke balun out of the last few feet of the coax nearest the antenna elements to keep stay rf off the coax shield. Without my trusty Drake MN-4 transmatch in the line, I got an initial SWR of 1.6:1. The "tuner" brought that down to 1:1 without much trouble. This antenna is not meant for permanent installation and it's a bit of a compromise, but, this easily assembled antenna will get you on the air with a decent signal. In an emergency, that may be all that's necessary to get a message to the outside world. Overall, this video does a pretty good job of making a basic, no frills dipole antenna. For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily.Aloha es 73 de Russ (KH6JRM).