I recall a whole chapter on W2PV's book which showed graphs of various
stacking distances. I am sure that there are other good publications. I
suggested this book to NY6DX because I find reading the material and
looking at the graphs more informative than someone on towertalk
suggesting to stack them at xx feet. FWIW, I have a 20m stack at 150' and
75' as you mentioned from W2PV's book and it works quite well.
John KK9A
To: <towertalk@contesting.com>
Subject: [TowerTalk] Stacking question
From: "Jim Thomson" <jim.thom@telus.net>
Date: Tue, 9 Aug 2016 09:26:43 -0700
There is a lot of information about stacking in books such as W2PV's Yagi
Antenna Design.
John KK9A
## take the w2pv info with a grain of salt. In one of his lectures, he put
the top 20m yagi
at 150 ft. Then tried the bottom yagi at 65/75/85 ft. On his software, the
gain peaked with
bottom yagi at 75 ft. The premise was, the bottom yagi was placed midway
between top yagi...and
the dirt ! IMO, if the top 20m yagi was instead at 200 ft, you would
not
place the bottom 20m yagi
at 100 ft...more like 130-140 ft. Then w2pv tried modeling a 3 high stack,
at 150/100/50..which smoked everything.
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