[TowerTalk] Vertical vs Beam

[Jim Brown]

I've studied this a bit, and about a year ago turned it into an 
applications note, and then a presentation at several hamfests. 

The app note is 

http://audiosystemsgroup.com/ComparingVerticalsandDipoles.pdf

The power point slides for the presentation are in 

http://audiosystemsgroup.com/LimitedSpaceAntennasPPT.pdf

As others have noted, there are many variables, all related to the 
vertical angle that you're trying to work (changes with band 
conditions), the efficiency of the antenna (usually radials, but 
also losses to, and distortion of the pattern by, surrounding 
objects), and the height of the beam. 

My conclusion -- a dipole at a "good" height will nearly always 
beat a vertical unless it's a VERY GOOD vertical, and a beam is 3-
8dB better than a dipole, depending on its size and design. I live 
in a forest, where dipoles and verticals are easy but a beam is 
difficult. I've tried very good verticals on 160, 80, and 40M, and 
the 160 vertical is the only one that is as good as the dipoles 
(and it's better than my 160 dipole, which is up 100 ft). That 160 
vertical is 86 ft of #10 copper, with another 100 ft of horizontal 
#10 copper as top-loading, and has 70 radials under it. 

Bottom line -- if you can put up a decent beam for 20-10, by all 
means do it. If you can't, try dipoles next. Verticals should 
usually be the LAST RESORT. Exceptions -- vertical arrays, like 4-
squares, etc. But even then, a high dipole is likely to work as 
well. For a lot more, see the pdf links.

73,

Jim Brown K9YC