John Smith wrote:
However, if
anyone has a view to the contrary, I would be interested in the
specifics ...

In a coil wound on an iron-core toroid, do you believe
the flux follows the wire in the coil and ignores the
iron in the toroid?

Coupling is, of course, not nearly that good in an air-
core coil but coupling exists nonetheless. Some of
the current generated in a coil is through the air-core
transformer action between coils.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
John Smith wrote:
[said, "gray areas exist!]

In a coil wound on an iron-core toroid, do you believe
the flux follows the wire in the coil and ignores the
iron in the toroid?


At designed freqs, permeability of core material, turns
size/spacing--the core OVERWHELMS all other forms of magnetic
coupling--I cannot even begin to think how I would measure EM coupling
between turns in such an environment ...

Coupling is, of course, not nearly that good in an air-
core coil but coupling exists nonetheless. Some of
the current generated in a coil is through the air-core
transformer action between coils.

Air core, EM coupling between turns exists, in what degree--I simply
cannot, probably, afford the equipment to measure ...

As I stated, for at least the most part, we are in agreement ... it
seems only logical ... however, things are not always as they seem (now,
how's that for "wiggle room?" ;-) )

Regards,
JS