QRZ11-Forum

Here seven bullet-proof yagi, from 3 to 8 elements, from 2.5 to 19 meter boom. Bullet-proof, why? Anything is scaled to 11m from the 10-Meter ARRL project. All are designed with one goal in the mind, to maintain a solid gain and F/B and SWR ratio over the band.


These are supposed to be feed by gamma-match, and elements are (electrically too) connected to boom via U-bolts and aluminium plates. The big ones require you add a compensator, i.e. a dummy (plastic) element on purpose to compensate wind load. Won't to tire, more private if need.

Aluminium tubing is for all yagi the same, i.e. same diameters and, for inner section, also same length, while outer must have his own length depending on element and design.


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So I will table only tip's length and element spacing.
Remember, if you're forced to use different diameter tubes, is maybe better to run computer again. Anyway with 12mm tips instead of 13mm the antenna shifts 100 Khz up, i.e. from 27.500 to 27.600


Try this first, if you want:



It's a comparative analysis of gain you can expect by these aerials, 11 meter up over average ground, for 10-degree elevation angle. Remember please, this is not necessarily and always the max gain of each yagi ... Anyway here is the gap from 8-foot to 62-foot, 6 dB.

Excuse me for my English, enjoy,

Paolo
July 28, 1999

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