Sunday, November 9, 2014

Simple Ham Radio Antennas: The End Fed Halfwave Vertical. Post #320.


A curiously fascinating "shoot out" between a 135-ft/41.15 meters OCF dipole antenna mounted 40-ft/12.19 meters above ground versus a 31-ft/9.45 meters halfwave vertical sitting on an apartment deck. The empirical "test" of Tony's (W1ZMB) OCF dipole and Stan's (WB2LQF) halfwave vertical shows that the simple vertical halfwave antenna performs almost as well as the OCF. The halfwave vertical has a few advantages over its fully extended OCF dipole cousin: It has a high feed point impedance which makes it efficient; it's simple to build and relatively inexpensive to assemble; it's versatile for both home and portable use; it doesn't require a ground radial system; and it can be used in a variety of configurations--sloper, inverted "L", or horizontal. All you need is a 31 ft/9.45 meters telescoping fiberglass pole (Jackite or MFJ), a homebrewed 9:1 balun, enough wire for a half wavelength vertical at your favorite frequency, a convenient length of 50-ohm coaxial cable, and an antenna "tuner" if you want to trim SWR to its lowest level. Stan's half wavelength antenna can be set up and broken down quickly--something that would appeal to portable operators. Excellent primer on the basics of the End Fed Halfwave Vertical Antenna. For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily. Thanks for joining us today! Aloha es 73 de Russ (KH6JRM).