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Old December 26th 07, 06:51 AM posted to rec.radio.amateur.antenna
John Smith John Smith is offline
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First recorded activity by RadioBanter: Nov 2006
Posts: 2,915
Default Standing morphing to travelling waves. was r.r.a.a WARNING!!!

Cecil Moore wrote:

...

I suspect what Dan is referring to is the LCLCLCLC
equivalent circuit for a transmission line. A horizontal
wire over ground is a one-wire transmission line with
Z0 = ~SQRT(L/C). A radiating antenna can be considered
to be a lossy transmission line.

A #14 horizontal wire at 30 feet calculates out to be
Z0 = 600 ohms so L/C = ~360,000. I'm pretty sure that
is the L and C that Dan is talking about - the same
L and C in which the standing wave energy is stored.


since:
2b
L = 0.00508((ln---) - 0.75) (best ascii can do)
a


whe
L = uH
a = wire dia in inches
b = wire length in inches
ln = natural logarithm
and, since #14 is .0641 inch
and 30 ft = 30*12 or 360 inches

2*360
L = 0.00508((ln(------)) - 0.75)
0.0641

L = .043568935605uH

Now, if I can just find that formula for the capacitance of a free wire
in space--I know I seen it here just a bit ago ... sorry, I'll have to
get back to you on that one ;-)

Regards,
JS