Topband: Tower-attached guy wires - max length for driven tower?
Jim Brown
jim at audiosystemsgroup.com
Fri Mar 27 11:42:58 PDT 2009
On Fri, 27 Mar 2009 13:31:55 -0400, Brian Machesney wrote:
>Since
>stubs of wire attached to a radiator can affect its behavior, is there a
>recommendation as to the maximum length of the guy wires whose ends are
>attached to the tower?
Those wires will act as a capacitive hat, making the antenna electrically
longer. That affects 1) the tuning and 2) the vertical pattern (because it
modifies the current distribution on the antenna). This can be very good, but
it is not trivial, and you need to model it in NEC. BTW -- if that tower is
also holding up some aluminum, that aluminum will provide additional
capacitive loading.
73,
Jim K9YC
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