w8io

The W8IO Antenna Site - 222-15V Yagi

(updated 10 Oct 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 scaled the 144-15V to 222 MHz and reoptimized at 222.1 MHz. In the 144-15V design, I adjusted the spacing and element lengths slightly to increase the Front/Rear to values over 30 dB in each plane. In the 222-15V design, the E-plane achieves an amazing 34.39 dB Front/Rear (all lobes from -90 to -180 degrees) and 31.3 dB Front/Rear in the H-plane at 222.1 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" DE and 3/16" parasitics).


222-15V Performance

Electrical Performance:                     0.188" Element Diameter 
Directive Gain (dBi)                                        16.61
Power Gain (dBi)                                            16.49
E-Plane F/R (dB)                                            34.39
H-Plane F/R (dB)                                            31.3
E-Plane 1st Sidelobe (dB)                              -20.6
H-Plane 1st Sidelobe (dB)                             -17.6
E-Plane Beamwidth (deg)                                 29
H-Plane Beamwidth (deg)                                 29
Max VSWR (222-225 MHz)                           1.6
4 Bay G/T (dB) at 3.4m (E) x 3.3m (H)          +3.23

Mechanical Performance:
Boom Length        19.5 feet        5.93 m        4.4 wavelength
Recommended Boom diameters: 1" to 1.5" either square or round (DX Engineering or On-Line Metals)
Recommended element insulators: Directive Systems (insulated through the boom)
Recommended element sources: On-Line Metals, McMaster-Carr

222-15V NEC file  EZNEC file (3/16" elements)


222-15V Dimensions

Element Cum Spacing
(m)
0.188" Element Diameter
Element Half-Lengths (m)
Dielectric Boom or NEC simulation

Element Full Lengths (inches)

Reflector 0 0.330
Driven Element
(0.250" OD)
0.1855 0.318
D1 0.273 0.3122
D2 0.459 0.3093
D3 0.808 0.3018
D4 1.224 0.297
D5 1.705 0.2921
D6 2.218 0.2882
D7 2.750 0.2843
D8 3.300 0.2814
D9 3.853 0.2795
D10 4.393 0.2791
D11 4.926 0.2781
D12 5.443 0.2736
D13 5.933 0.2645



Driven Element details (in):



4NEC2 Patterns:





Comments are welcome!

contact Roger: email to 

rgcox2 (at) gmail.com

Roger Cox - Spring Lake, MI