Canvey Island, Essex, England Justin@g0ksc.co.uk
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
previous arrowprevious arrow
next arrownext arrow
 
Read Time: 7 - 13 minutes

A 9el 12.5 Ohm 50MHz Optimised Wideband Low impedance (OWL) Yagi

Premium commercial versions of this antenna at Innovantennas

 

Revised  February 2010

 

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 50MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With almost 14.05dBi and a boom less than 12.5M long, this antenna will be a winner for field days and the rural Ham radio operator.

 

PLEASE NOTE:
  • 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 details

The 8el OWL installed at ZL1RS

Performance UK/USA Version

Forward Gain:                           14.05dBi at 50.250MHz

Front to Back Ratio:              22.67dBi at 50.250MHz

Peak Gain:                                 14.07dBi

Peak F/B:                                22.73dB

Bandwidth:                               500KHZ below 1.2:1

 

Build Dimensions for UK/USA Version

Element           Spacing in metres Half element Length in metres            Element Notes

Reflector               0                                   1.491                                              12.7mm 1/2 inch Diameter tube

DE                       .270                               1.448                                               12.7mm  1/2 inch tube

D1                       .769                               1.411                                              12.7mm 1/2 inch Diameter tube

D2                     1.908                               1.375                                               12.7mm 1/2 inch Diameter tube

D3                     3.687                               1.3425                                             12.7mm 1/2 inch Diameter tube

D4                     5.790                               1.3215                                             12.7mm 1/2 inch Diameter tube

D5                     8.029                               1.297                                               12.7mm 1/2 inch Diameter tube

D6                     10.446                              1.2845                                            12.7mm 1/2 inch Diameter tube

D7                     12.438                              1.291                                              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                                   1.492                                              12mm Diameter tube

DE                       .270                               1.449                                              12mm Diameter tube

D1                       .769                               1.412                                              12mm Diameter tube

D2                     1.908                               1.376                                               12mm Diameter tube

D3                     3.687                               1.3435                                             12mm Diameter tube

D4                     5.790                               1.3225                                             12mm Diameter tube

D5                     8.029                               1.298                                               12mm Diameter tube

D6                     10.446                             1.2855                                             12mm Diameter tube

D7                     12.438                             1.292                                               12mm Diameter tube

 

 

Fantastic Azimuth plot of this 9el 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

Read Time: 4 - 7 minutes
A 6el 28 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 above.

Do not look at the gain figure of this antenna and compare with other 6 element 50MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With 11.8dBi and a boom less than 6.2M long, this antenna will be a winner for field days and the rural Ham radio operator.

PLEASE NOTE:

  • Special attention should be taken in ensuring the element spacing and sizes are absolutley correct upon a 28 Ohm Yagi
  • If SWR is not perfect, D1 may also need to be adjusted. An analyser is reccomended for use when finalising 28 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 details

Performance UK/USA Version

Forward Gain:                           11.8dBi at 50.250MHz

Front to Back Ratio:              31.86dBi at 50.250MHz

Peak Gain:                                 11.82dBi

Peak F/B:                                32.02dB

Bandwidth:                               500KHz below 1.1:1

Build Dimensions for UK/USA Version

Element    Spacing in metres Half element Length in metres    Element Notes

Reflector               0                                   1.488                           12.7mm 1/2 inch Diameter tube

DE                       .529                              1.4415                          12.7mm  1/2 inch Tube

D1                      1.075                               1.3915                         12.7mm 1/2 inch Diameter tube

D2                     2.435                               1.3565                          12.7mm 1/2 inch Diameter tube

D3                     4.326                               1.327                            12.7mm 1/2 inch Diameter tube

D4                     6.175                               1.2925                          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                                   1.488                          12mm Diameter tube

DE                       .529                               1.442                          12mm Diameter tube

D1                      1.073                               1.3915                        12mm Diameter tube

D2                     2.435                               1.3565                         12mm Diameter tube

D3                     4.326                               1.327                           12mm Diameter tube

D4                     6.175                               1.2925                         12mm Diameter tube

Fantastic Azimuth plot of this 6el 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