[TowerTalk] SteppIR 40/30 and loading
tongaloa
tongaloa at alltel.net
Wed Nov 5 12:45:54 EST 2003
K3BU at aol.com wrote:
>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.
>
Yuri-
Interesting charts, but in the real world wouldn't one be comparing
antennas to which equal
power is delivered rather than antennas with equal currents at the
current maximum?
-Bob
ah7i
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