A 13el 28 Ohm 144MHz 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 13 element 144MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With 16.44dBi (10mm element version) and a boom less than 8.3M long, this antenna will be a winner for field days and the rural Ham radio operator. Class leading G/T 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:                           16.43dBi at 144.300MHz

Front to Back Ratio:              26.61dBi at 144.300MHz

Peak Gain:                                 16.47dBi

Peak F/B:                                26.81dB

Bandwidth:                               1.9MHz below 1.1:1

Build Dimensions for UK/USA Version

Element           Spacing in metres Half element Length in metres    Element Notes

Reflector               0                                   .512                                 3/8 inch tube

DE                       .202                               .4955                               1/2 inch tube

D1                       .383                               .4775                                3/8 inch tube

D2                       .845                               .465                                 3/8 inch tube

D3                     1.484                               .4555                                3/8 inch tube

D4                     2.236                               .4475                                3/8 inch tube

D5                     3.045                               .441                                  3/8 inch tube

D6                     3.901                               .4355                                3/8 inch tube

D7                     4.779                               .430                                  3/8 inch tube

D8                     5.672                               .4255                                3/8 inch tube

D9                     6.583                               .421                                  3/8 inch tube

D10                   7.508                              .4205                                  3/8 inch tube

D11                   8.256                              .433                                    3/8 inch tube

Build Dimensions for European Version

Element           Spacing in metres Half element Length in metres     Element Notes

Reflector               0                                   .5115            10mm tube

DE                       .202                               .496              12mm tube

D1                      .381 .477                                            10mm tube

D2                       .845                               .4645            10mm tube

D3                     1.484                               .455              10mm tube

D4                     2.236                               .447              10mm tube

D5                     3.045                               .4405             10mm tube

D6                     3.901                               .435               10mm tube

D7                     4.779                               .4295             10mm tube

D8                     5.672                               .425               10mm tube

D9                     6.583                               .4205              10mm tube

D10                   7.508                              .420                 10mm tube

D11                   8.256                              .4325                10mm tube

Antenna Plots

Fantastic Azimuth plot of this 13el 144MHz 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 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. 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 at all, please Email me!

Justin G0KSC