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Ch22 11-El FD-Yagi - 300ohm K7MEM
Ch22 11-Element Folded Dipole Yagi (518-524 MHz) analyzed using 4nec2 [see *.nec.doc file below].
Design Dimensions for 11-El Yagi from rabbit73 post, calculated using fol. K7MEM Website:
http://www.k7mem.com/Electronic_Notebook/antennas/yagi_vhf.html

Note that K7MEM Dimensions [for Cutting Elements] must be SHORTENED by the "Boom Correction"
= BC * Element Diameter, when 4nec2 Model is constructed WITHOUT the METAL Boom, where BC=0.666.
Boom Correction for ACTIVE Element is derated by 50% due to being mounted ABOVE the Boom.

Ch22 11-El FD-Yagi - 300-ohm K7MEM:
Ch22 Raw Gain = 14.3 to 14.5 dBi, F/B & F/R Ratio Min. = 16.7 dB and SWR (300-ohms) = Under 1.8.
BOOM LENGTH = 1433-mm (56-13/32 inches).

Unfortunately, K7MEM (like other "Formula Driven" Designs), are NOT OPTIMIZED [poor F/B & F/R Ratios].
Gain, F/B & F/R Ratios were Best on 529 MHz, vice desired 518-524 MHz and SWR Curve for 200-ohms
is better than 300-ohms, although Both are "Acceptable" [not always true].
Date(s): 4 Jul 2016. Album by holl_ands. 1 - 18 of 18 Total. 1763 Visits.
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Ch22 11-El FD-Yagi - 300ohm K7MEM
3D View


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Front View
[1 large square = 1.25 inches]


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Top View
[1 large square = 5 inches]


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Raw Gain Maximum on 529 vice desired 521 MHz
F/B & F/R Maximums on 529 vice desired 521 MHz


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Ch22 SWR (300-ohms) Under 1.8
SWR Minimum on 529 vice desired 521 MHz


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Ch22 SWR (300-ohms) Under 1.2
SWR Minimum near desired 521 MHz


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Azimuthal Pattern at 518 MHz


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Azimuthal Pattern at 521 MHz


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Azimuthal Pattern at 524 MHz


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Elevation Pattern at 518 MHz
Elevation Beamwidth TWICE what Chart says


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Elevation Pattern at 521 MHz
Elevation Beamwidth TWICE what Chart says


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Elevation Pattern at 524 MHz
Elevation Beamwidth TWICE what Chart says


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Ch22 11-El FD-Yagi - 300ohm K7MEM
4nec2 File includes Summary of Dimensions


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Ch22 11-El FD-Yagi - 300ohm K7MEM
EVAL Summary of Performance


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Ch22 11-El FD-Yagi - 300ohm K7MEM
EVAL *.html Performance Summary


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Ch22 11-El FD-Yagi - 300ohm K7MEM
UHF Impedance


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Ch22 11-El FD-Yagi - 300ohm K7MEM
Top View
[1 large square = 5 inches]


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