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Old January 14th 04, 07:07 AM
Cecil Moore
 
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Tdonaly wrote:
There's also a frequency where
the two circuits are 180 deg. out of phase, but current isn't flowing into
two ends of the coil - or capacitor - at the same time. I hope
there's no one on this newsgroup gullible enough to take your
fractured circuit theory seriously.


Kraus says: "It is generally assumed that the current distribution
of an infinitesimally thin antenna is sinusoidal, and that the phase
is constant over a 1/2WL interval, changing abruptly by 180 degrees
between intervals."

If I locate a loading-coil such that the phase change node is
in the middle of the coil, current-in will be 180 degrees out of
phase with current-out. In a two-terminal series circuit, if the
net current-in is 180 degrees out of phase with the net current-out,
those two currents are either flowing into the coil at the same time
or flowing out of the coil at the same time 1/2 cycle later.

Consider a 1.5WL helical dipole. The two net currents at 0.4WL and 0.6WL
are flowing in opposite directions.

Consider something even more bizarre. If the coil is exactly 1/2WL and
each end is located at a current node, assuming the forward current is
equal to the reflected current (Kraus' assumption) then zero net current
is flowing in and out of both ends of the coil even though there is a
current maximum point in the middle of the coil. This is how Kraus'
phase-reversing coil works in his collinear array antenna.
--
73, Cecil http://www.qsl.net/w5dxp



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