Dual Band Quads

21Mhz OWA Yagi Antennas

A 9el 28 Ohm 144MHz Optimised Wideband Low impedance (OWL) Low Temperature Yagi

Revised  August 2014

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 9 element 144MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With 14.76dBi (10mm element version) and a boom less than 5.2M long, this antenna will be a winner for field days and the rural Ham radio operator. Class leading G/T and sky 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:                           14.76dBi at 144.300MHz

Front to Back Ratio:              24.53dBi at 144.300MHz

Peak Gain:                                 14.78dBi

Peak F/B:                                24.71dB

Bandwidth:                               1MHz below 1.1:1

Sky Temp. TA:                         234.1 Kelvin

G/T:                                       -8.95dB

 

Four bay array (in metres) - 3.1V x 3.325H

Sky Temp. TA:                         227.9 Kelvin

G/T:                                        -3.01dB

Gain:                                       20.57dBi

 

Build Dimensions for UK/USA Version

Element  Spacing in metres  Half element Length in metres   Element Notes

Reflector               0                                   .5055                      3/8 inch tube

DE                       .364                               .4845                      1/2 inch tube

D1                       .664                               .4725                      3/8 inch tube

D2                     1.232                               .4585                      3/8 inch tube

D3                     1.930                               .4485                      3/8 inch tube

D4                     2.734                               .4405                      3/8 inch tube

D5                     3.585                               .433                        3/8 inch tube

D6                     4.488                               .4235                      3/8 inch tube

D7                     5.248                               .4305                      3/8 inch tube

 

Build Dimensions for European Version

Element  Spacing in metres  Half element Length in metres   Element Notes

 

Reflector               0                                   .505                      10mm tube

DE                       .364                               .485                      12mm tube

D1                       .665                               .472                      10mm tube

D2                     1.232                               .458                      10mm tube

D3                     1.930                               .448                      10mm tube

D4                     2.734                               .4395                     10mm tube

D5                     3.585                               .4325                     10mm tube

D6                     4.488                               .423                       10mm tube

D7                     5.248                               .430                       10mm tube

 

Antenna Plots

 

Fantastic Azimuth plot of this 9el 144MHz OWL Yagi

 

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

 

 

Measurement taken with coaxial stub inserted within the software model. 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