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Old August 15th 06, 06:01 AM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 168
Default QFH Antenna and 72ohm TV Coax

On Mon, 14 Aug 2006 23:04:30 GMT, Owen Duffy wrote:



PS: I think the problem you have given can be solved with simple trig:
find the reactance of the Z02 section using one trig term,


Z=-j50*cot(45)=-j50

find the
length of Z01 that would deliver that reactance using one trig term,


l=acot(50/600)=85.2

add that length and the actual length of Z01 section, find the


Z01'=85.2+45=130.2

reactance of the Z01 section using one trig term. I could do that in a


X=-j600*cot(130.2)=j507.7

flash with a scientific hand calculator while you were sharpening your
pencil.

It is a trivial problem either way, and can only ever be an
approximation of a practical problem.


But you wouldn't get that accuracy from the Smith chart.

Owen
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