Originally posted by skyspotter
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First, the lower limb of dipole was removed to make it a monopole. Next step was a clever thing: bend down the phasing stub to make it inline with monopole instead of being perpendicular to it . This resulted in J-Pole to be an end-fed antenna, and made it's installation much easier than center-fed dipoles.
The trikiest thing in J-pole, Slim Jim and Franklin dipole with matching stub is the accurate placement of cable tap off on the stub. At Ghz frequencies, few mm away from optimum point, and the antenna transforms from "very good" to "poor". At lower frequencies, where dimensions are big, it is much easier to accurately place cable tap-off.
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