Thread: skin depth decay
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Old November 21st 07, 05:38 AM posted to rec.radio.amateur.antenna
Roy Lewallen Roy Lewallen is offline
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First recorded activity by RadioBanter: Jun 2006
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Default skin depth decay
Richard Clark wrote:
On Tue, 20 Nov 2007 16:23:45 -0800, (Dave Platt)
wrote:

Bailey gives two impedance figures - the "surge"
impedance and the feedpoint impedance

Re pg 340:
"By definition, the surge impedance of a conductor
for all practical purposes is that value of load
resistance which, if placed at the end of the
conductor, will completely prevent refelcted power
from being sent back into the conductor by
the load."

Less conductor periphery, more surge Z.

Some representative values:
Thin dipole 610 Ohms (Thin = #10 wire @ 200MC)
Dipole 420 Ohms (0.5" @ 200MC)
Thick Dipole 240 Ohms (Thick = 2.5" @ 200MC)
Vertical 260 Ohms (.25" @ 200MC)
Biconical 150 Ohms

YMMV

Ok, I give up. I've got a dipole in free space. I connect one end of the
load resistance to one end of the dipole. What do I connect the other
end of the resistor to?

If that's too tough, how about just a dipole a quarter wavelength above
ground?

Roy Lewallen, W7EL
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