Thread: Yagi efficiency
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Old December 4th 06, 02:54 AM posted to rec.radio.amateur.antenna
art art is offline
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First recorded activity by RadioBanter: Sep 2006
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Default Yagi efficiency

Ofcourse they are.They are both resonant and have the same "Q" which is
equivalent to half power. Isnt that why we talk of a half power width
of a main beam because of the assertion I just made. This is a
excellent candidate for a complex circuit analysis since the Q is the
same regardles of movement away from the resonant frequency and
coupling is not a factor!
Art
Art

Cecil Moore wrote:
art wrote:
Cecil Moore wrote:
Actually Art, adding reactance reduces the current in
the element thus *decreasing* losses below what a resonant
passive element would have. Pure reactance is lossless.


This current that you are referring to, I used P =I squared R
which leads to lower power. Where did I go wrong


Lower power results in lowering the loss due to heat.
That leaves more power available to be radiated by
the antenna system but not necessarily radiated by
this single element that we are discussing. I suspect
two driven elements are theoretically capable of
better performance than a two element Yagi given
equal total power input into the elements.
--
73, Cecil http://www.w5dxp.com