In a message dated 11/5/03 10:16:22 AM Eastern Standard Time,
wa3gin@erols.com writes:
>>>No. A properly designed lumped inductance is better than linear
>loading. That's why many 80 meter Yagi owners have upgraded to
>W6ANR's aftermarket loading inductors, replacing the original linear
>loading. Linear loading is a marketing concept to make you think
>you have eliminated the ohmic losses associated with loading
>coils. Instead, it *increases* the losses.
>
>Rick N6RK
><<
Amen and Ditto!
For those interested and willing to immerse in the "war" about the Current
Distribution in Antenna Loading Coils, significance on the efficiency of
antennas, problems with understanding and modeling vs. reality see my article
and
some comments at
http://www.k3bu.us/loadingcoils.htm
The arguments are flying at the Newsgroup
rec.radio.amateur.antenna
in the thread
"Current in antenna loading coil controversy"
Original articles that started the "war" were on eHam.net by K0BG
The importance of this phenomena is that efficiency of loaded or shortened
antennas is roughly proportional to the area under the current distribution
curve along the element. Loading stubs or coils "eat" the portion of the
current
curve and reduce the area/effciency. Top loading (T or L) "eats" just the tip
of the current curve, least area. T loading cancels out the "other"
polarization, L loading radiates it. The best application is in Moxon
Rectangle, where it
provides also element coupling and fantastic F/B for two element antenna. The
current distribution in the loading coils has significant effect on the
design of loaded multielement beams, software so far cannot "stomach" it.
ON4UN's
Low Band DXing has it right.
I don't want to start another war here, rather point to what was already
rehashed and with W9UCW and W5DXP we will prepare concise article on the
subject,
put it on web site and submit to ARRL/QST publications (19th edition of ARRL
Antenna Book has it wrong)
Yuri, K3BU.us
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