View Single Post
  #4   Report Post  
Old April 19th 05, 02:06 AM
ml
 
Posts: n/a
Default


i am not clear on how this antenna would look, when i think of 2
elements "" phased or simul driven i presumed it would sorta look like
a typical beam elements in parrallel spaced apart

that being the case , i am not clear on how changing the feedpoint
alters the ew ns direction

unless of course the antenna is like a cross


the gain seemed nice wouldn't mind trying one, my catch is i am using a
sgc tuner to feed my present dipole, i suppose i could just take it's
output and feed both 'elements' be a neet experiment

thanks
m


Years ago I experimented with two-element beams where both
elements were driven. Roy, W7EL, has some BASIC programs
on his web page that allows the calculation of phasing
harnesses for such antennas. The disadvantage is that one
must know the mutual coupling impedance between the two
elements.

In article , Cecil Moore
wrote:

Given that EZNEC will output the feedpoint impedances for
both elements, for a common class of two-element beams,
the mutual coupling impedance can be calculated from the
EZNEC data. Assuming the two-element beam consists of
two identical center-fed elements and assuming that the
feedpoint current magnitudes are equal, one can design
the beam to meet certain specifications, obtain the
feedpoint impedances from EZNEC, and calculate the
mutual coupling to be entered into Roy's BASIC phasing
software.

Lewell1.bas program available as simpfeed.zip on www.eznec.com.

One advantage of a wire beam like this is that the direction
of maximum gain can be reversed by changing the feedpoint
position on the coaxial phasing harness. Good E-W or N-S
beam performance is obtained with one fixed wire beam on the
lower bands.
--
73, Cecil, W5DXP