Ian White GM3SEK wrote:
Evidently I was in too much of a hurry to leave for the GMDX convention,
because what I mean to write next was:
"Cecil's theory does not work for this test case, "
[ I definitely did type the word "not", but it accidentally disappeared
from the version that was posted. ]
Well there you have it, folks. Gurus don't even make typo mistakes.
Some evil server removed that "not" on purpose from Ian's posting.
Cecil's theory does not work for this test case,
because it requires that basic electrical properties like current and
inductance switch into a different kind of behaviour in what he calls
a "standing wave environment".
RF current switches from a different kind of behavior than DC current.
Phase, capacitance, inductance, and wavelength all have to be taken
into account in the steady-state analysis. That is a technical fact
that I'm sure you appreciate.
Why is it such a stretch to recognize that standing wave current behaves
differently from traveling wave current? That standing wave current is
different from traveling wave current is readily apparent from the
equations. In the following equations, 'K' is used for a constant,
'z' is the linear distance up and down the line, and 'w' is omega.
Forward traveling wave current = K1*cos(kz+wt)
Reflected traveling wave current = K2*cos(kz-wt)
Standing wave current =
K1*cos(kz+wt) + K2*cos(kz-wt) = K3*cos(kz)*cos(wt)
If tK1 = K2, then the standing wave doesn't move. Please dust off
your old math books and realize what the above equations imply at
a physical level.
--
73, Cecil
http://www.qsl.net/w5dxp