[Antennas] Open Wire

2002年12月12日 15:16:00 -0500

Bob,
You say a 'doublet' is a 'closed circuit' .. that's incorrect... you 
must mean a 'FOLDED DIPOLE' which IS a CLOSED CIRCUIT.
Don
N8DE
You wrote:
This thread on 450 ohm open line has been interesting. I use 450 ohm 
ladder line
here and it works great for me. This thread reminds me of my original 
mentor when
I got into ham radio some 55 years ago, who used 600 open wire feeders 
to a random
doublet. The late Wilson Rowell, ex W2HHL used a 135 foot doublet fed 
with 600 Ohm
open line at about 50 feet off the ground. The beauty of this antenna 
was that in
severe icing conditions Wilson would connect a 10V, 20amp filament 
transformer across
the 600 Ohm open line and melt ice off of his antenna. Remember that a 
doublet is
a closed circuit, so the antenna appears as a short to the transformer.
Some in North Carolina should have been using this in the past few weeks.
I used a similar antenna at Eglin AFB back in 1966 when they first came 
out with the
first open wire feed line (before ladder line as we know it) and it 
worked great,
but of course there was no ice to worry about.
Bob Wilder, AF2HD/AFA2HD