[TowerTalk] Loading tower

[n4kg@juno.com]

When the effective height ( tower plus toploading ) is much 
greater than 1/4 Wavelength (WL) the pattern gets complicated
and considerable energy may be lost in high angle lobes.  This 
means that most towers are way too long for 40M.   On 80M,
a 40 ft tower and beam makes a nice elevated GP or shunt
fed vertical with ground radials.  Taller towers are useful on 
160M but may or may not do well on 80, especially if there
are other Yagi's side mounted on the tower.  See my
article on elevated GP antennas in June 1994 QST. 

On 40M (and 30M), a 24 ft  BOOM of a grounded element
tribander or 20M beam makes a great rotary dipole using 
a gamma or omega  match.

de Tom  N4KG


On Sat, 15 Jan 2000 12:54:19 -0500 "WA9ALS - John"
<jfleming@shelbynet.net> writes:
> 
> I've read about using the tower as a 160M vertical, and the 
> associated
> matching system(s).  Anyone doing that for 40M and/or 80M??  Is that
> covered in the ON4UN book??  Is there a way to do it (well) with a 
> tuner
> and use it on 40M *AND* 80M?
> 
> WA9ALS - John  jfleming@shelbynet.net
> http://www.qsl.net/wa9als
> 
> 
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