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Old November 6th 03, 06:14 PM
Richard Harrison
 
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Yuri, K3BU wrote:
"Are the FACTS in the way of coil "must" have the same current theory?"

Sure. Power traveling along a radiator is absorbed in resistance, both
loss and radiation resistance, so it is diminished by the time it gets
to a reflection point, the tip of the antenna. This is not like a coil
without an opportunity to radiate or which is small in terms of
wavelength.

Often an extreme example is more impressive than the mediocre. For
instance, complete reflections on a lossless line make clearer examples
of phase patterns than slight mismatches on a lossy line.

For a coil, use the example of the "normal helix antenna". At one of the
radio broadcast stations where I worked in 1949, was an operator, James
L. Davis, W5LIT who wrapped a bamboo fishing pole completely from end to
end with wire in the form af a solenoid, using it as his rear bumper
mounted 75-meter phone mobile antenna. When he modulated, the corona at
its tip echoed his voice.

Obviously, there was a huge difference in the drivepoint current (high)
of this antenna, a continuous coil, and the current at the tip (low).
The voltage was the reverse of its end currents, being high where the
current was low and being low where the current was high. J.L. Davis was
very pleased with his mobile operation.

Best regards, Richard Harrison, KB5WZI

 
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