[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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