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Old November 7th 03, 12:57 AM
Tarmo Tammaru
 
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Steve,

You are right about the gain. I ran EZNEC on the 75 meter loop, and the gain
at 40 m is about 3db more than on 75. However, it is not resonant in band. I
got an impedance at 3850 of 40 + j5. Impedance at 7700 of 69 +j1, and
impedance at 7300 of 18 + j87 (That is an SWR of 10). Gets worse below
7300.

There is enough feedline and wire loss in the real world antenna that the
SWR measured from the shack is about 5:1 on 40 m.

Tam/WB2TT
"Desmoface" wrote in message
...
That was the whole point. 7700 is out of band.

Tam/WB2TT


Yeah, but its two wavelengths, it should probably perform at least as good

or
better on 40 than it does on 80?? It would most certainly have a lower

angle of
radiation. Again, I'm no electrical engineer, but I've always been led to
believe that the bigger the antenna the better...it should certainly

resonate
efficiently on 10-80, in theory anyway..in the same way that a full wave

is
better than a half wave or a quarter wave.

See: http://www.ku4ay.net/loop.html and
http://www.cebik.com/atl1.html which are just a few of the sites

discussing
these fine antennas..

Steve
kb8viv



 
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