5-element Triband Yagi Antenna TH-5 Mk2

The Hy-Gain TH-5 Mk2 is a 5-element three-band beam antenna designed for operation in the 10, 15 and 20 metre amateur bands. Broadbanding is accomplished through the use of two fully trapped driven elements. Stainless steel hardware and clamps are used on all electrical connections and a 50Ω BN-86 balun and preformed feed straps are included. The antenna is designed to fit masts from 1.9" to 2.5" (50 mm to 63.5 mm) in diameter.

Electrical specifications

VSWR under 2:1 :  14-14.35, 21-21.45, 28-29.4 MHz
VSWR under 1.5:1 :  14.09-14.32, 21.11-21.45, 28.25-29.15 MHz
Front-to-back ratio:  20m 19+/-5, 15m 22+/-5, 10m 19+/-5 dB
Average 1/2-power beamwidth:  20m 67˚, 15m 66˚, 10m 66˚
Maximum gain:  20m 7.8 dBi, 15m 8.0 dBi, 10m 9.0 dBi
Maximum power:  1 kW
Lightning protection:  DC ground

Mechanical specifications

Boom length:  5.8 m
Boom diameter:  5.1 cm
Longest element:  9.6 m
Longest driven element (one-half total length):  20m 0.183 wavelength, 15m 0.206 wavelength, 10m 0.227 wavelength
Turning radius:  5.6 m
Net weight:  25.8 kg
Maximum wind survival:  100 mph (161 kmph)
Effective wind area:  0.68 m²
Effective moment:  144 kg-m
Wind load at 80 mph:  86 kg
Projected area:  Elements 0.94 m², Boom 0.3 m²

The VSWR curves given are typical for the antenna mounted 70 feet above ground, horizontally polarised. If guy wires are used, they should be broken up into non-resonant lengths and insulated from the tower if mounted within 10 feet of the top.

Here you find 13 models, 13 with images and 2 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Hy-Gain Electronics Corporation; Lincoln (NE)