October 7th 04, 08:07 AM
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On 07 Oct 2004 05:39:57 GMT, ospam
(Theplanters95) wrote:
It looks like I could place a loop around the eaves of my house and it would,
in theory, be resonant around the 40m band. I'm planning on either feeding it
with ladder line or use a 4:1 balun with a very short run into the house.
How can I make the antenna also resonant on 75m? I am planning on using it for
75m-10m.
Hi Randy,
It would help to have dimensions. Presumably the perimeter is 40
meters, or thereabouts. As you stand very little chance of one
antenna being resonant on all bands, you may as well anticipate tuning
on the majority of them.
As such, it behooves you to avoid dimensions that are problematic
(presenting a hi-Z impedance). The first likely opportunity will be
with 20M. If you carefully choose your transmission line length to
handle this, you may find you've forced the problem into another band.
As such, some flexibility is in order. One such forethought would be
to have a way to open the loop at the point opposite to the feed (or
perhaps kicks in a tuning cap). This says nothing of the matching
problem that has not already been said (be prepared), but it may be a
simple variation that yields new solutions.
73's
Richard Clark, KB7QHC
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