Canvey Island, Essex, England
Twin boom quad
144MHz LFA Yagis
144MHz LFA Yagis

Low Noise LFA Yagis designed by G0KSC free to build for personal use.

144MHz LFA Yagis
70cms LFA Yagis
70cms LFA Yagis
Twin-Boom G0KSC Quads
G0KSC Twin-Boom Quads
Twin-Boom G0KSC Quads
G0KSC Custom Dish feeds - Above installation @ HB9Q
Custom low-noise dish feeds
Custom low-noise dish feeds
G0KSC Custom Dish Feeds

Above installation @ HB9Q

G0KSC Custom Dish feeds - Above installation @ HB9Q
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Read Time: 6 - 12 minutes
 A 8el 12.5 Ohm 50MHz Optimised Wideband Low impedance (OWL) Yagi

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 in the CONSTRUCTION menu.

Do not look at the gain figure of this antenna and compare with other 8 element 50MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With almost 13.3dBi and a boom less than 10M long, this antenna will be a winner for field days and the rural Ham radio operator.


  • Special attention should be taken in ensuring the element spacing and sizes are absolutley correct upon a 12.5 Ohm Yagi
  • If SWR is not perfect, D1 may also need to be adjusted. An analyser is reccomended for use when finalising 12.5 Ohm OWL Yagis
  • 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 G0KSC insulators. Other insulators may require different correction, email me for more details

The 8el OWL installed at ZL1RS

Performance UK/USA Version

Forward Gain:                           13.26dBi at 50.150MHz

Front to Back Ratio:              26.85dBi at 50.150MHz

Peak Gain:                                 13.27dBi

Peak F/B:                                26.90dB

Bandwidth:                               500KHZ below 1.12:1

Build Dimensions for UK/USA Version

Element           Spacing in metres Half element Length in metres            Element Notes

Reflector               0                                   1.5145                                            12.7mm 1/2 inch Diameter tube

DE                       .200                               1.460                                               12.7mm  1/2 inch tube

D1                       .537                               1.4235                                             12.7mm 1/2 inch Diameter tube

D2                     1.575                               1.3775                                             12.7mm 1/2 inch Diameter tube

D3                     3.346                               1.342                                               12.7mm 1/2 inch Diameter tube

D4                     5.469                               1.315                                               12.7mm 1/2 inch Diameter tube

D5                     7.741                               1.293                                               12.7mm 1/2 inch Diameter tube

D6                     9.782                               1.283                                               12.7mm 1/2 inch Diameter tube

Build Dimensions for European Version

Element           Spacing in metres Half element Length in metres            Element Notes

Reflector               0                                   1.5105                                            12mm Diameter tube

DE                       .200                               1.4615                                             12mm Diameter tube

D1                       .532                               1.4255                                             12mm Diameter tube

D2                     1.575                               1.380                                               12mm Diameter tube

D3                     3.346                               1.344                                               12mm Diameter tube

D4                     5.469                               1.3165                                             12mm Diameter tube

D5                     7.741                               1.2955                                             12mm Diameter tube

D6                     9.782                               1.2815                                             12mm Diameter tube

Fantastic Azimuth plot of this 8el 50MHz OWL Yagi

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

This SWR plot is taken with the Coaxial stub embedded within the EZNEC model Ever seen a 12.5 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. Note the close spacing of the first 3 elements which give the OWL its extra gain and wide bandwidth.

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

Justin G0KSC