On Oct 24, 2005, at 9:37 AM, <ku8e at bellsouth.net> wrote:
> A shortened antenna works better than a full size antenna???
Other things equal, I'd say NO. But, other things are not equal.
> The A743 is the add on for 30 meters.
40 or 30m
> It looks like it is just a capacitance hat
> that is added to the driven element. The only advantage I see is
> you now have a rotatable antenna on 30 meters.
The kit has several components to beef up the DE. Electrically, it
adds a set of 20m traps and element extensions that bring the overall
DE length to 35 feet. The capacity hats are used only on 40m.
> A 125 doublet with open wire would be very close to two half
> waves in phase
> giving you a bi-directional pattern broadside to the wire... Seems
> like it would work better.
You'd think.
However, the 125 foot doublet is low - only 30 feet in the middle, 35
feet on the ends. The A743 is at 50 feet. This little bit of height
makes all the difference in the world.
The difference is dramatic. About 1-2 S-units between the two antennas.
It goes back to the rule of thumb for horizontal antennas -- the
single most important dimension is height above ground in wavelengths.
Made my first 160m EU QSO from home last night. S58A gave me 559 at
around 0400z. I think the shunt feed works.
Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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