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Old December 4th 03, 05:08 PM
Richard Harrison
 
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Roy, W7EL wrote:
"So tell you what. If you`ll pull out your equations and calculate the
expected current difference, I`ll replace the coil with one of 100 ohms
reactance and remeasure."

The challenge was directed to Cecil, but anyone can respond. The current
is a function of position along the antenna. Distribution is
cosinusoidal as Yuri said.

Yuri Blanarovich posted ON4UN`s Fig 9-22 from "Low-Band DXing".
45-degrees of the 90-degree total length of a center-loaded whip comes
from the loading coil. Current tapers cosinusoidally from 1A at the
drivepoint to 0A at the tip.

Current into the bottom of the coil is 0.924A and into the top of the
coil it is 0.383A. These are related to the cosines of 22.5-degrees and
67.5-degrees, 0,924 and 0.383.

The expected current difference in ON4UN`s example is 0.54A.

Best regards, Richard Harrison, KB5WZI