Dual Band Quads

21Mhz OWA Yagi Antennas


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A 13el 12.5 Ohm 144MHz Optimised Wideband Low impedance (OWL) Very 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 13 element 144MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With 16.27dBi and a boom of 8.1M long and a single antenna sky temperature of 223.1 Kelvin, this antenna will be a winner for all those seeking the most quiet antenna of this size for 2M. Excellent G/T figures too! This antenna also has an incredible 1MHz 1.1:1 bandwidth 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
  • This is a Very Low Temperature antenna, ideal for EME work

 

Performance UK/USA Version

Forward Gain:                           16.27dBi at 144.300MHz

Front to Back Ratio:                 26.46dBi at 144.300MHz

Peak Gain:                               16.31dBi

Peak F/B:                                28.61dB

Bandwidth:                              1MHz below 1.1:1

Sky Temp. TA:                        223.1 Kelvin

G/T:                                        -7.25dB

 

Four bay array (in metres) - 3.85V x 3.995H

Sky Temp. TA:                         219.2 Kelvin

G/T:                                        -1.28dB

Gain:                                       22.13dBi

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                                   .510                                             3/8 inch tube

DE                       .183                               .486                                             1/2 inch tube

D1                       .445                               .470                                             3/8 inch tube

D2                       .749                               .4605                                           3/8 inch tube

D3                     1.287                               .4575                                           3/8 inch tube

D4                     1.991                               .4495                                           3/8 inch tube

D5                     2.780                               .443                                             3/8 inch tube

D6                     3.621                               .4375                                           3/8 inch tube

D7                     4.499                               .432                                             3/8 inch tube

D8                     5.396                               .426                                             3/8 inch tube

D9                     6.317                               .419                                             3/8 inch tube

D10                   7.228                               .411                                             3/8 inch tube

D11                   8.104                               .417                                             3/8 inch tube

 

Build Dimensions for European Version

Element           Spacing in metres Half element Length in metres            Element Notes

 

Reflector               0                                   .5095                                         10mm tube

DE                       .183                               .487                                            12mm tube

D1                       .445                               .4695                                          10mm tube

D2                       .749                               .460                                            10mm tube

D3                     1.287                               .457                                            10mm tube

D4                     1.991                               .449                                            10mm tube

D5                     2.780                               .4425                                          10mm tube

D6                     3.621                               .437                                            10mm tube

D7                     4.499                               .4315                                          10mm tube

D8                     5.396                               .4255                                          10mm tube

D9                     6.317                               .4185                                            10mm tube

D10                   7.228                               .4105                                          10mm tube

D11                   8.104                               .4165                                          10mm tube

 

Antenna Plots

 

Fantastic Azimuth plot of this low temperature 13el 144MHz 12.5Ohm OWL Yagi

 

The Elevation plot is really clean too. A super quiet antenna, find one the same size that is more quiet!

 

A Super quiet antenna that is wideband? Another first from G0KSC. Watch how many now appear on the Internet but remember where you saw them first!

 

  

The G0KSC OWL element layout. Note the close spacing of the first three elements. My 'secret' to wide band low impedance antennas I now release for all to use.

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

 

Justin G0KSC