Survivalism & Self Sufficiency Topics > Amateur Radio How-To's

Inpedance matching for Collapsible Yagis (for field use)

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Greekman:
New question.....

The assembly of the feed point and match etc, is becoming intricate, especially in the way it integrates in the boom...
At this point I need a proof of concept before going further into construction.

So, is it possible to asssemble on a piece of wood only the driven elements without the reflector and directors and take meaningful SWR measurents?

I *think* it is as the driven elements would work like a dipole, and i think both this and a Yagi are about 70ohms of

Carl:
The driven element can be tested alone,but is effected when additional elements are added or even located closer/farther from the driven element.

Greekman:
you mean its tuning...it figures

armymars:
  As you add more elements it will often lower the impedance of the antenna. Many 3 element beams have a impedance of 23 ohms or so. The hair pin match helps take care of this. Adjust the hair pin match first for the lowest SWR, then go up and down the band to see where the antenna likes to be. If it's not where you want it then adjust the driven element length. You might have to adjust the hair pin to fine tune it.

Greekman:
thanks!

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