[Elecraft] Buddipoles and KX1

Geoffrey Mackenzie-Kennedy gm4esd at btinternet.com
Fri Apr 18 07:30:16 EDT 2008


Mike Morrow  <kk5f at earthlink.net> wrote on Thursday, April 17, 2008 9:12 PM

> One can make contacts with even the poorest of antennas, and not realize 
> how
> poor the performance is.  Side-by-side tests out in the boonies is the 
> real
> test of relative performance.  Nothing beats that!

----------------------------------------------------------

Absolutely!  For a number of years at this rural location I used full sized 
vertical dipoles for 40m in phased arrays and as omnidirectional antennas, 
with their top ends at approximately 70ft.  It became painfully obvious 
after a while that in their favoured directions these vertical antennas 
performed better on DX paths when firing across open farm fields than when 
firing through nearby large trees, such as oak, when their sap was running 
i.e Spring through Fall. As an example the long path to Japan is roughly 
16600 miles from here across open fields, the short path roughly 4900 miles 
through nearby trees, and the long path across the fields into JA was always 
'easier' to work than the short path when using the verticals.

So I put up a horizontal 40m dipole at 70ft which also fires towards Japan. 
Not only did the tree problem appear to disappear, but also the dipole's 
better performance at low angles compared with that of the vertical antennas 
found from side-by-side tests, made on 40m over a long period, was very 
apparent on both the short and long paths into Japan. The penalty is that 
the low angle nulls off the ends of a horizontal dipole at this height are 
very noticeable on long distance paths when the angle of arrival is low.

73,

Geoff
GM4ESD






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