Topband: Inverted L

Brad Rehm bradrehm at gmail.com
Mon Jan 12 17:19:36 EST 2009


I would like to know opinions on whether to go with a ground radial
system or if an elevated counterpoise would work better.
Thanks   Darl   NA8W

Darl,

I've just finished an Inverted-L for topband, using four 135 ft.
elevated radials.  The radials are made from 17 Ga. fence wire, and
they're each about 9 feet above ground.  The ends are supported by 12
ft. T-posts.

I was pleased to find the feed impedance is 20 j9 Ohms.  This suggests
that losses in the radial system are very low, and the antenna was
easily matched with a 2.25:1 balun taken right out of Sevik.

The antenna works very well, and I'd suggest that if you can build
with elevated radials, do it.  Otherwise, get ready to bury about 50
radials in the ground to achieve the same efficiency.  (See
www.antennasbyn6lf.com for a discussion of elevated vs. ground-mounted
radials.)

73,
Brad, KV5V


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