Sunday, January 10, 2016

Simple Ham Radio Antennas--Doublet aerial for HF amateur ham radio short wave bands


This is Post #654. If you're having trouble viewing this video, please insert this address into your browser search box: https://youtu.be/8ZmyvtMvEGY.  Here's another well-done, easy- to- understand antenna tutorial from Ray of the "Radio Workshop."  This time, Ray explains the theory, construction, and use of the classic multiband "doublet aerial", which is simply a multiband dipole antenna fed by 300 ohm television twin lead, 450 ohm ladder line, or twin feeders of your own design.  If you cut the dipole for the 80 meter band (i.e. around 3.500 MHz) and use balanced feeders attached to a balanced tuner, you will be able to use the "doublet aerial" on any amateur radio band between 80 and 10 meters.  You can also run the tuned feeders into a 4:1 current balun and then onto your usual tuner with a short length of 50 ohm coaxial cable.  Place the "doublet aerial" as high as you can.  If you have only one antenna support, you can use this antenna in the inverted V configuration with only a small loss in performance.  One of my backup antennas at my Puna District (Hawaii Island) home is an inverted 80 meter inverted V using a tree branch approximately 40-feet/12.19 meters above ground level to support the apex of the antenna.  Using  450 ohm ladder line, a 4:1 current balun, and my trusty Drake MN-4 antenna transmatch (tuner), I have a reliable back up antenna that be used in portable or emergency situations.  Ray has done an excellent tutorial and offers many helpful hints on how to make this classic antenna.  For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are update daily.  You can follow our blog community with a free email subscription or by tapping into the blog RSS feed. Thanks for joining us today!  Aloha es 73 de Russ (KH65JRM).