HF J-Pole. Post #1200.
HF J-Pole (http://www.eham.net/articles/39180). Accessed on 25 July 2017, 20:00 hrs, UTC. Author: Mike Higgins (K6AER). Please enter link into your browser search box to read the full article. Comment: Most radio amateurs are acquainted with the J-Pole antenna, which finds a ready application for our shared VHF/UHF bands. The antenna is simple, easy to make with commonly available materials, and provides a modest amount of gain. In this post, Mike Higgins (K6AER) describes the HF version of the J-Pole antenna scaled for both 20 and 40 meters. He briefly describes how the antenna is designed and built: "There is nothing special about a J pole, it is an end fed ½ wavelength vertical radiator that needs no radials. Just like its 2-meter brother but on 20 meters it is ten times larger. The bottom ¼ matching section is fed with 50-ohm coax. Bottom of the antenna is shorted and the coax attaches at the 50 ohm point in the matching transformer. The higher the attach poi