Dave G4GED <mailto:radiodave.g4ged@tiscali.co.uk>
Tuesday, August 13, 2013 3:04 AM
It's popular because relatively few operators have the space or
facility for two tall strong end supports.
The L has always worked very well indeed for me and my DXCC score says
so :-)
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Topband Reflector
Herb Schoenbohm <mailto:herbs@vitelcom.net>
Sunday, August 11, 2013 6:15 PM
Why is an inverted "L" apparently so popular on 160 when it wastes so
much RF as a cloud warmer? It is so easy converting an inverted "L"
into a Marconi T. The flat top can be 130 feet fed exactly in the
center by a single drop wire to the ground with the appropriate
network. A 65 foot drop wire comes very close to 50 ohms and any
reactance can be removed with a series capacitor. Apart for the
cancellation of high angle radiation this configuration is some
distance away from support structures. So many try to configure an
inverted L by using their metal towers as supports for the fed end.
This sometimes means you are just shock exciting the metal tower and
your feed impedance results may be all over the ball park.
I challenge anyone to find a situation where an Inverted "L" will
outperform a properly configured Marconi "T" with an ample ground
system on either.
Herb Schoenbohm, KV4FZ
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Topband Reflector
Don Johnson <mailto:n4dj@me.com>
Sunday, August 11, 2013 5:48 PM
I have not seen a length mentioned for the inverted L, so thought I
would note that by making the inverted L longer than a quarter wave
moves the high current portion up the vertical. I had good luck with
an inverted L about 3/8 wave long. By good luck I mean DXCC plus some
on 160. I still am trying to improve. In any event feeding the
inverted L with a series capacitor made tuning a breeze. By going
longer than a quarter wave made the feed point inductive and raised
the R value closer to 50.
73,
Don
N4DJ
Sent from my iPhone
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Topband Reflector