On Tue, 29 Sep 2009 10:30:19 -0400
Guy Olinger K2AV <olinger@bellsouth.net> wrote:
> A 160 meter inverted L can be used quite successfully on
>80 and 40.
Guy,
You are correct to say that the 160 inv will have a high
impedance feed point on 80 which is not as difficult to
feed as some may think.
However, the 160 inv L on 80 meters is a poor DX antenna.
It has mostly high angle radiation. NEC modelling will
show that. We've also found that out the hard way on the
VK9WWI DXpedition, where we used a 160 m inv L for 80 (fed
via a tuner). The antenna performed very poorly for NA and
EU (but the JA-s heard us well). Eventually we realized
that if we lowered the horizontal wire and brought it to
the antenna base for 80 meter operation, performance would
improve. For the VK9GMW Mellish Reef operation we designed
an antenna that overcame this problem. It had part of the
"horizontal" wire bent down and grounded for 80 meter
opration. As many will testify, it worked. (The
description of the antenna is available as a downloadable
PDF document at
http://vk9gmw.com/documents/VK9GMW_ANTENNA.pdf )
73,
George
AA7JV
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