A 8el 28 Ohm 144MHz Optimised Wideband Low impedance (OWL) Yagi Low Temperature Yagi

Revised  February 2010

Premium commercial versions of this antenna at Innovantennas

The OWL by G0KSC provides the benefits of both OWA (Optimised wideband Array) 50 Ohm antennas with those of traditional low impedance antennas. More information on the OWL can be found here

Visit HERE to learn how to make the OWL Match/Balun

Do not look at the gain figure of this antenna and compare with other 8 element 144MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With 14.04dBi (10mm element version) and a boom less than 4.3M long, this antenna will be a winner for field days and the rural Ham radio operator. Class leading G/T  and temperature figures too!

PLEASE NOTE:

• Visit 'Making the OWL Match' for more information on the recommended matching methods
• Please add 2mm to each element to allow for insulator correction if using insulators similar to G0KSC. If through boom/insulator/element bolts are used, add 3mm

Performance UK/USA Version

Forward Gain:                           14.04dBi at 144.300MHz

Front to Back Ratio:              23.51dBi at 144.300MHz

Peak Gain:                                 14.08dBi

Peak F/B:                                  25.27dB

Bandwidth:                               1.2MHz below 1.1:1

Sky Temp. TA:                          239.8 Kelvin

G/T:                                         -9.79dB

Four bay array (in metres)  - 2.8V x 3.050H

Sky Temp. TA:                         232.7 Kelvin

G/T:                                       -3.85dB

Gain:                                       19.82dBi

Note: all G/T and sky temperature figures at 144.100MHz

Build Dimensions for UK/USA Version

Element           Spacing in metres  Half element Length in metres            Element Notes

Reflector               0                                   .506                                             3/8 inch tube

DE                       .365                               .484                                             1/2 inch tube

D1                       .663                               .4715                                           3/8 inch tube

D2                     1.233                               .4565                                           3/8 inch tube

D3                     1.931                               .4475                                           3/8 inch tube

D4                     2.718                               .440                                             3/8 inch tube

D5                     3.587                               .4255                                           3/8 inch tube

D6                     4.337                               .430                                            3/8 inch tube

Build Dimensions for European Version

Element           Spacing in metres  Half element Length in metres            Element Notes

Reflector               0                                   .5055                                          10mm tube

DE                       .365                               .485                                            12mm tube

D1                       .663                               .471                                            10mm tube

D2                     1.233                               .456                                            10mm tube

D3                     1.931                               .447                                            10mm tube

D4                     2.718                               .4395                                          10mm tube

D5                     3.587                               .425                                            10mm tube

D6                     4.337                               .430                                            10mm tube

Antenna Plots

Fantastic Azimuth plot of this 8el 144MHz OWL Yagi

The Elevation plot is really clean too. A quiet antenna compared with most!

Ever seen a 28 Ohm antenna like this one before? Watch how many now appear on the Internet but remember where you saw them first!

The G0KSC OWL element layout.

As always, or if you have difficulty at all, please Email me!

Justin G0KSC