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Old January 27th 08, 08:41 PM 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 Derivation of Reflection Coefficient vs SWR

Richard Harrison wrote:
Roy Lewallen wrote:
"A better reason to avoid "stored" is that power isn`t stored at all,
anywhere. Anyone who believes so should be able to tell us how many
watts are stored in a 50 Ah, 12 volt battery."

The 50 Ah of energy stored in a battery may be withdrawn at a rate
determined by the load, so it is a variable.


Ah is a unit of charge, not energy. The battery, making the simplifying
(and invalid) assumption of constant voltage during discharge, contains
2.16 Mj of energy.

Velocity in a transmission line is a constant determined by
constructtion of the line. Thus, energy stored in the line is determined
by its length, voltage, current, and phase angle. These predict the rate
of energy transfer (power).


So the rate at which a transmission line transfers energy depends on its
length? If I put 100 watts into a one wavelength cable and get 100 watts
out, will I get 200 watts out if I extend the cable to two wavelengths?

Roy Lewallen, W7EL