Posted by
Steve Jackson-5 on
Jun 10, 2005; 8:36pm
URL: http://elecraft.85.s1.nabble.com/Re-K1-KAT1-FD-OCF-dipole-tp379219p379220.html
--- Mike Morrow <
[hidden email]> wrote:
> I guess my question is: Why choose this type of
> antenna?
Our Field Day setup uncludes a 66' pneumatic bucket
truck. The bucket holds up a central rope, and from
that is supported my dipole center.
The bucket truck is set in place by the power company
at 9 AM on Saturday morning and is retracted only at
2:30 PM Sunday. We can't operate the bucket.
> Baluns of any type especially warrant
> avoidance if losses are of concern.
Properly-constructed baluns are not lossy, provided
they have the right impedances on each side.
> For more than 30 years, portable HF operation has
> been my main interest in ham radio. In that
> interval I've tried almost every conceivable type,
> home-made and commercial-made: dipoles fed with
> coax, doublets fed with ladder line, verticals,
> loops, etc. (but no beams). I've found that
> absolutely nothing ever worked as well as the simple
> cheap light-weight coax-fed resonant half-wave
> dipole...nothing else even comes close.
I mostly concur. With the obvious exception of beams,
as you say, monoband wire dipoles can't be beat -
except by monoband extended-double-Zepps (better
pattern), by coaxial double bazookas (better
bandwidth), and (in narrow bandwidths) by
exaggerated-wall magnetic loops (tolerant of low
mounting height). That's why I use all four of these
antenna types, depending on the circumstances.
> For the four band K1, a 40m dipole with three
> insulators with jumpers spaced properly in each leg
> will produce a very compact, low-cost, resonant
> antenna for each K1 band. No balun is needed at the
> antenna, and you'll have the coax feed you need.
That would be fine, if I wanted to (or could) raise
and lower the antenna.
The OCF dipole is the best multiband compromise
antenna for my specific application, provided I can
make a good match to it.
What will probably happen if I can't find a good
design for a 6:1 balun in time to make one ... I will
wind a 4:1 balun and feed it with RG-6, then null out
the slight mismatch at the rig using the ATU.
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