Hi Morrison. Read your post and thought I would ask Mark Wilson, K1RO
Editor of QST, to look into it. He, in turn, asked Dean Straw, ARRL's
antenna guru. Here's his response. -73- Steve Mendelsohn, W2ML
ARRL First Vice President
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From: Straw, Dean, N6BV
To: Wilson, Mark K1RO
Subject: RE: Error in ARRL Antenna Book??
To: <towertalk@contesting.com>
Date: Monday, June 30, 1997 12:44PM
Mark:
Previous editions stated the gain over ground (without specifically saying
so!). The 6.7 dBi gain in the 17th Edition (and the 18th too) is
specifically stated to be in free space. This models very well using NEC2,
by the way.
Add about 5.5 dB for a good ground reflection, and you get 12.2 dBi for the
peak gain over ground, or about 10 dBd over a dipole in free space.
Previous to the 17th Edition, writers tended to be a little sloppy about
whether the antenna was in free space or not...
If I were VK3BCY, I'd stick with the much simple pure Yagi design in the
17th or 18th Edition. It is mechanically a lot simpler than an LPDA and
works every bit as well.
73, Dean, N6BV
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