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quarter waves...

>(Message lost, content remembered):
>The discussion of 1/4 wave length windings:
>I was thinking of the 1/4 wavelength discussion and the discussion about the
>wire "appearing shorter" when wound into a solenoid.  I then thought that I 
>would take the specs for a working coil and reverse engineer it to see what 
>values I got for the wire length.
	good.  I was thinking of doing the same, but did not.

>I found that the length of the wire closely approximated 1/4 of the
>wavelength of a light wave at that frequency. (C = lf, or speed of light =
>wavelength * frequency).
	hmmmmmmm.

>Initially this seemed to contradict the "shortening" phenomenon.
	I was lifting that from radio practice.  It may not fully apply, or

>Upon reflection, I decided that the purpose of the toroid on top
	The toroid has many purposes.  One of its effects

>is to "lengthen" the wire or drop the frequency to a value where the wire
>length works out to the 1/4 light wave length.
	Say rather that the assembly resonates as if it were a free space
	quarter wave.

>So, the questions to those who know, are:
>1) Is my figgering correct?
>2) Is this a pointless consideration, that has no real bearing on the 
>   real world of coil design?  (I don't want to fixate on a hair splitting
>   issue, but if it is important to a good design, I want to know.)
	I think it is a real consideration.  secondaries are notorious for
	not agreeing with the calculated values.  radio/antenna experience may
	not be totally applicable.  And it is based on (i suspect) longer coils
	than typical tesla secondaries.

>>> check the draw with RMS volt and ammeters
>Does any one know of a good source for ammeters that read in the tens of amps?
>I have only seen milliamp meters, except for the expensive inductively coupled
>electrician's ammeters.
	One can shunt hem, with resistors, but teh need to be high watt
	reistors.  Beware reistors that change value with temperature.
	In any case get to know where the local electronic junque stores are,
	and when and where the ham radio fleas are.  Meters to 50A, FS, are
	stock items.  Above that is generally current trasformers....

	regards
	dwp