w8io

The W8IO Antenna Site - 144-16V Yagi

(updated 28 Sep 2016)

This particular antenna design was inspired by Hartmut DG7YBN and he was inspired by Gnter DL6WU and Brian K6STI. His designs blend extremely high antenna gain, high G/T (which means a low noise temperature) along with a broad gain and VSWR bandwidth. The DE design is also very easy to build and allows adjustment of VSWR without significantly affecting the gain and pattern performance. A broad VSWR and gain bandwidth is ideally suited for wet and snow/ice climates where accumulation of moisture on the elements can lower the antennas resonant frequency and degrade performance. In this design, I have adjusted the spacing and element lengths slightly to increase the Front/Rear to values over 30 dB in each plane. The E-plane achieves an amazing 35.8 dB Front/Rear (all lobes from -90 to -180 degrees) at 144.1 MHz. This allows the antenna to reject terrestrial noise sources to an extremely high degree for improved EME performance in noisy locations. Element diameters are common US sizes (1/4" and 3/16").


144-16V Performance

Electrical Performance:                     0.250" Element Diameter            0.188" Element Diameter
Directive Gain (dBi)                                        16.87                                            16.77
Power Gain (dBi)                                            16.76                                            16.65
E-Plane F/R (dB)                                            35.8                                              35.91
H-Plane F/R (dB)                                            32.3                                              31.93
E-Plane 1st Sidelobe (dB)                              -19.6                                             -19.7
H-Plane 1st Sidelobe (dB)                             -16.8                                             -16.8
E-Plane Beamwidth (deg)                                28.4                                              28.4
H-Plane Beamwidth (deg)                                30.0                                              30.0
Max VSWR (144-146 MHz)                           1.5                                                1.5
4 Bay G/T (dB) at 4.6m (E) x 4.4m (H)          -0.55                                            -0.55

Mechanical Performance:
Boom Length        32.3 feet        9.86 m        4.73 wavelength
Recommended Boom diameters: 1" to 1.5" either square or round (DX Engineering or On-Line Metals)
Recommended element insulators: Directive Systems
Recommended element sources: On-Line Metals, McMaster-Carr

144-16V NEC file  EZNEC file (1/4" elements)
144-16Vse NEC file  EZNEC file (3/16" elements)

144-16V Dimensions

ElementCum Spacing
(m / in)
0.250" Element Diameter
Element Half-Lengths (m)
Dielectric Boom or NEC simulation
0.250" Ele Dia
Element Full Lengths (inches)
with Dielectric Boom
0.250" Ele Dia
Element Full Length (in)
including metal Boom Correction
1", 1.125", 1.25", 1.375", 1.5"
0.188" Element Diameter
Element Half-Lengths (m)
Dielectric Boom or NEC simulation
Reflector0/00.509540.1180.51205
Driven Element
(0.375" OD)
0.286 / 11.2600.4905100mm = 3.937"
490.5mm = 19.311"
(boom center to tip)
0.4905
D10.421 / 16.5750.48237.9530.4845
D20.707 / 27.8350.477537.5980.480
D31.246 / 49.0550.46636.6930.4685
D41.886 / 74.2520.458536.1020.4610
D52.628 / 103.4640.45135.5120.4535
D63.419 / 134.6060.44535.0390.4475
D74.239 / 166.8890.43934.5670.4415
D85.086 / 200.2360.434534.2130.437
D95.939 / 233.8180.431533.9760.434
D106.771 / 266.5740.43133.9370.4335
D117.592 / 298.8970.429533.8190.432
D128.388 / 330.2350.43033.8580.4325
D139.160 / 360.6290.42333.3070.4255
D149.860 / 388.1880.402531.6930.405



Driven Element details (in):
DE


4NEC2 Patterns:
az

el


Comments are welcome!

contact Roger: email to 

rgcox2 (at) gmail.com

Roger Cox - Spring Lake, MI