Elevated verticals

ezimmerm at erols.com ezimmerm at erols.com
Sat Dec 7 02:15:41 EST 1996


As I remember it, the original description of an elevated vertical system 
appeared in a May 1957 CQ magazine article by Dale Hoppe, W6VSS (now 
K6UA) who has one of the first if not the first multi-multi 
superstations.  This antenna was a parasitic quarter wave vertical array 
for 40 meters.  By trial and error Dale determined that a height of 10 
feet (3 meters) above ground was correct and that the ground losses 
appeared to be minimized or absent at this height.  Higher did not appear 
to improve the antenna.  He also found that more than 4 radials were 
unneccesary.  What he has here you may recognize as a ground plane 
antenna, which is much more common at higher frequencies like 10 meters 
or at VHF.

I used such an antenna first in the 1960's at the W4BVV multi-multi.  We 
judged that if 10 feet was good for 40, 20 feet (6 meters) would be good 
for 80 and 40 feet (13 meters) would be good for 160.  Indeed this is 
what we found.  Our pair of phased ground planes elevated 6 meters on 80 
was a killer antenna for its time on 80.  And the 160 meter full sized 
vertical elevated 13 meters was very effective into Europe.

These heights above ground were confirmed by antenna modelling on a main 
frame computer in the early 1970's.  It is interesting that WA3FET who is 
one of the people who originally converted the mainframe NEC code into 
the MININEC programs we use on PC's to model antennas today gave an 
interesting talk on modeling elevated verticals at the Dayton Hamvention 
a few years ago.  He was unaware of Dale's original article and modeled 
the verticals de novo and came out with heights essentially identical to 
what had been derived empirically 40 years before.

So you should raise the antenna 10 feet for 40 meters, 20 feet for 80 
meters and 40 feet for 160 meters.  As a compromise, for an all band 
vertical, 20 feet should be a good height for the base.  4  60 
foot (20 meter) radials should work well.  Of course if you cannot make 
the radials that long, make them as long as possible.  We drooped them 
down toward the ground and secured them to short pieces of wood.  You can 
make them go to any height at the ends that is convenient and safe for 
people walking aroung them.

73  Gene  W3ZZ

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