**** YAGI UDA ANTENNA ****
Design by http://www.changpuak.ch/electronics/yagi_uda_antenna.php
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Frequency  :  145  MHz
Wavelength :  2068.966  mm
d/lambda   :  0.001    ( min.: 0.001 , max.: 0.04 )
D/lambda   :  0.004    ( min.: 0.002 , max.: 0.04 )
Boomlength :  828  mm
Elements   :  3
Gain       :  7.1  dB    (approx.)
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Reflector Length [mm] : 1022
Reflector Position [mm] : 0
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Dipole Length [mm] : 997
Dipole Position [mm] : 414
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Director Length [mm] : 969
Director Position [mm] : 828
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Calculations based on NBS TECHNICAL NOTE 688
Length might be slightly too long.
Manufacturing Tolerances : < 4  mm 

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VK5DJ's YAGI CALCULATOR

Yagi design frequency =145,00 MHz
Wavelength =2068 mm
Parasitic elements contacting a square section metal boom 8 mm across.
Folded dipole mounted same as directors and reflector
Director/reflector diam =2 mm
Radiator diam =2 mm

REFLECTOR
1016,9 mm long at boom position = 30 mm

RADIATOR
Single dipole 989,9 mm tip to tip, spaced 414 mm from reflector at boom posn 444 mm

DIRECTORS
Dir	Length	Spaced	Boom position	Gain	Gain
(no.)	(mm)	(mm)	(mm)		(dBd)	(dBi)
1	961,2	155,1	598,6		4,8	6,9

Spacings measured centre to centre from previous element
Tolerance for element lengths is +/- 6 mm

Boom position is the mounting point for each element as measured from the rear of the boom and includes the 30 mm overhang.
The total boom length is 629 mm including two overhangs of 30 mm

The beam's estimated 3dB beamwidth is 92 deg

A half wave 4:1 balun uses 0,66 velocity factor RG-58C (PE)  and is 682 mm long plus leads