Wikipedia on “Transmission Line”
The Wikipedia entry
on “Transmission Line” http://en.wikipedia.org/wiki/Transmission_line
is dreadful, and the reason why it is dreadful is the subject which at the
moment exercises Forrest and me. It links with “Where are they?” http://www.ivorcatt.co.uk/x256.pdf
which says; “They do not grasp the transverse electromagnetic wave.” I caught Wik out with omitting the Zo for
a lossless transmission line, a more obvious error than others in the entry. I
find that when I modify a Wikipedia entry my mods are
removed within hours. However, not always. For
instance, I modified an error in Wik on “Ivor Catt” http://en.wikipedia.org/wiki/Ivor_Catt
when it wrongly said I “transferred to engineering” while in Cambridge. This
correction has survived for a couple of months. I worry about changing Wik, because two men nearby have been banned from Wik – Nigel Cook and Tombe. Of
course, this has stopped Cook from continuing to attack me. See some attacks .
I must write out
Pythagoras’ theorem the way they persistently write “the telegraph equation”.
That is, they refuse to first treat the perfect case, where Zo=√µ/Ɛ . They immediately have resistive conductors and lossy dielectric, or in the case of the Wik
entry, reflections. They do not realise that there must be no reflections in
all their USB cables. In the case of Pythagoras, we would start with lines of
finite thickness, not lines of zero thickness, as Pythagoras did. Then we would
not have h2=a2+b2 .
Take the internal area of the three squares. Then if the lines have width 2x,
the formula becomes something like (h-x)2=(a-x)2+(b-x)2
. If the line width was x, not 2x, it would become even more complicated. It is
with this latter kind of formula what students of electromagnetism are
assailed. As with Pythagoras, the platonic form contains deep meaning which is
lost with the “practical” form. For example, the impedance of free space is √µ/Ɛ
, and there are no loss terms.
I shall write
something in “Talk” in Wikipedia for “transmission line”, and see what happens.
Ivor Catt 4 February 2013