Unlike some more conventional Yagis the feedpoint impedance at the
centre of the Moxon Driven element is very close to 50 Ohms; you just
need a Common-Mode choke at the feedpoint to reduce the likelihood of
current flowing along the outside surface of the coax braid.
Steve G3TXQ
On 03/08/2014 21:06, L L bahr wrote:
Also, the feed point on all the versions I have looked at couple an RF choke
right to the center point area of the Director. When I built a couple plain
Yagi antennas, I used a Gamma Match or T match thus tapping the Director
element at a 50 ohm point rather then at say at a 15 ohm point or so right at
the center of the director. Why is this not done on the W6NL building
examples? Is it because they think and hope the RF balun choke is going to
keep the mismatch SWR in check? Can anyone explain this to me? I'm not sure,
but I suspect the impedance right at the center of the Director is not 50 ohms
or even close to being 50 ohms.
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