--100ma & Above --79ma
When I moved the coil to the top of the mast and made
a horizontal "X" top hat to resonate it back on the
same freq, I got
--100ma & Above --47ma
So, It happens even in a totally shielded loading coil with miniscule
power going thru it! Kirchoff has no laws about current
being the same on both ends of inductors. His current law is about
one POINT in a circuit and his voltage law is about a closed loop."
... and some significant
difference W9UCW in field strength measured between the base and
center loading coil:
"The actual difference in signal strength between top
and base loading of a 9' antenna is about 16 db (measured) on
75m, but Tom calculates 8db on 160. That's because he assumes
the same current in the coil. Actually it's worse on 160 than
Barry's pictures are worth a thousand words:
W9UCW's setup with
radial field (60), base loaded vertical with RF thermocouple ammeters
inserted at the top and bottom of the coil.
Here is the coil in
center loaded radiator, 100 mA meters at both ends of the coil.
The bottom one is showing full deflection (with power adjusted
to) - 100 mA while at the same time the top ammeter is showing
45 mA as described above. The meters were mounted that way so
that they could do a test and then just turn the coil assembly
upside down and do another test to make sure results were the
same and that no anomalies crept in. Results were always identical.
So how does the real
distribution of current in loaded antennas look? The answer can
be found in the John Devoldere's "Bible" - "ON4UN's
Low Band DXing", 3rd Edition, on page 9-34: (see
When I pointed out
this reference to W8JI, his response was:
"I just looked
at that, and you are right. John is incorrect, and I'll bring
it to his attention. Thanks for pointing that out."
This is not the first
time that W8JI is wrong. His typical modus operandi is first to
attack and ridicule the opponent, then the exchange of arguments
ensues. When he realizes he is wrong, rather than admitting, he
clouds the issue with his "arguments". After staying
quiet for a while, he then emerges, pretending to be the expert
on the subject with corresponding postings on his web page, without
giving credit to the originator. Normally this is called plagiarism.
The Internet is a
great place to publish ideas, good and wrong. In the spirit of
Tom's posting on the eHam.net's purpose, I had to react to his
disinformation by presenting the facts, especially when it happened
more than once.
is this important? Technical subjects have their laws and rules.
Perpetuating wrong information doesn't serve anybody. As we can
see in this example, something that was "established"
50 years ago, perpetuated through "peer reviewed" books
to this day, can cause problems and wrong conclusions.