A 3el 12.5/50 Ohm 50MHz Optimised Wideband Low impedance (OWL) Yagi

Revised August 2010 V1.0

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 6 element 50MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With 7.75dBi and a boom less than 1.3M 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
A Folded dipole can be added in order to give this antenna a 50 Ohm feedpoint.

The 3el mini Yagi at G0KSC's 2010 summer holiday location, Cornwall UK

Performance UK/USA Version

Forward Gain: 7.48dBi at 50.250MHz

Front to Back Ratio: 25.57dBi at 50.250MHz

Peak Gain: 7.49dBi

Peak F/B: 25.88dB

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 1.5055 12.7mm 1/2 inch Diameter tube

DE .311 1.403 (FD) 12.7mm 1/2 inch Tube

D1 1.200 1.331 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 1.506 12mm Diameter tube

DE .311 1.404 (FD) 12mm Diameter tube

D1 1.200 1.332 12mm Diameter tube

NOTE: This antenna is fitted with a Folded dipole made form a G0KSC Stauff clamp either side of a 30/32mm square boom holding either 12mm or 1/2inch tube. The end sections are 10mm or 3/8 inch bent sections adjusted for best SWR.