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Old April 29th 06, 10:38 PM posted to rec.radio.amateur.antenna
Cecil Moore
 
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Default Missing Degrees in Mobile Antennas?

wrote:
Earlier we both agreed the current we measure with a magnetic probe,
which is the most common and widely accepted measurement device, is the
actual current that causes radiation, heating, and the magnetic
induction field. It is the current that heats the element and moves a
thermocouple meter, it is the current that cause I^2R heating, and the
current that moves past one point in the system if we stopped and
counted charges, or if we calculated current based on drift velocity of
charge carriers.


It is the current that has the equation: Itot = Io*cos(kx)*cos(wt)
Until you take time out to understand the implications of that
equation, you will *never* understand what I am talking about. That
current cannot be used to measure delay. Yet, that is exactly what
you and W7EL did and, in your ignorance, reported as valid measurements
of delay through a coil. If you had a clue to what you are saying, you
would feel ignorant in the extreme.

So what current is it you are measuring? Charges cannot flow two
directions at the same time at the same point in a system. There cannot
be drift velocity in two dorections at the same time.


Just as two water waves can flow in opposite directions using the
same water molecules, two EM waves can flow in opposite directions
using the same electrons.

Are you talking about a pulse of current and the return echo?


You know that I am talking about the distributed network model,
a superset of the lumped circuit model. Instead of rehashing it
here, please refer to my magazine article at:

http://www.qsl.net/w5dxp/energy.htm

and tell me what it is about that article that you don't understand.

2. There is no appreciable standing wave current phase shift from
feedpoint to the tip of the stinger in a 75m mobile bugcatcher
antenna. To be consistent, don't you have to argue that the
75m mobile bugcatcher antenna is zero degrees long?


It is however long it is.


Exactly the same argument holds for a coil. Think about it. You
cannot deny the validity of standing wave current phase measurements
through a stinger and then turn around and deny that same argument
when it applies to a coil. If W7EL's phase measurements were invalid
for a stinger, then they were equally invalid for a coil.

I never said 1.0, as a matter of fact the coil I measured had a vF
(when compared to physical length) of about .5


Sorry, that's still about 1000% too high, still completely out
of the ballpark. What I suspect is that you measured zero delay
through the coil and reported 3 nS because you knew zero was
obviously wrong.
--
73, Cecil http://www.qsl.net/w5dxp
 
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