> This brings up a big question in my small mind. Assuming you need to
correct element length, I can see you can use SWR to adjust the driven
element. But how do you correctly know how to correct or adjust the
reflector,
or for that matter any parasitic element? During the Dark Ages when I
first got licensed, you just made the reflector around 10% longer then the
driven element. How do you do it in 2014? (I really don't want to think of
remote field strength measurements while adjusting the parasitic element.)
If you correct the driven element by 1 inch to lower the SWR, do you then
just adjust the reflector by the same
What you do is to feed the element just like dipole and adjust it for
the frequency of interest. This is easy to do with split elements like the
F12. Just leave the other elements open and tune each one.
I think F12 used something like 2.5-3% or so instead of the 10% you
mentioned. If the manufacturer doesn't give you the element resonance, you
could model it for your requirements.
With non-split elements, I'm not sure how you'd do them.
Cheers,
Steve K7LXC
TOWER TECH
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