A 9el 28 Ohm 144MHz Optimised Wideband Low impedance (OWL) 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 9 element 144MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With 14.76dBi (10mm element version) and a boom less than 5.2M long, this antenna will be a winner for field days and the rural Ham radio operator. Class leading G/T and sky temperature 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: 14.76dBi at 144.300MHz
Front to Back Ratio: 24.53dBi at 144.300MHz
Peak Gain: 14.78dBi
Peak F/B: 24.71dB
Bandwidth: 1MHz below 1.1:1
Sky Temp. TA: 234.1 Kelvin
G/T: -8.95dB
Four bay array (in metres) - 3.1V x 3.325H
Sky Temp. TA: 227.9 Kelvin
G/T: -3.01dB
Gain: 20.57dBi
Build Dimensions for UK/USA Version
Element Spacing in metres Half element Length in metres Element Notes
Reflector 0 .5055 3/8 inch tube
DE .364 .4845 1/2 inch tube
D1 .664 .4725 3/8 inch tube
D2 1.232 .4585 3/8 inch tube
D3 1.930 .4485 3/8 inch tube
D4 2.734 .4405 3/8 inch tube
D5 3.585 .433 3/8 inch tube
D6 4.488 .4235 3/8 inch tube
D7 5.248 .4305 3/8 inch tube
Build Dimensions for European Version
Element Spacing in metres Half element Length in metres Element Notes
Reflector 0 .505 10mm tube
DE .364 .485 12mm tube
D1 .665 .472 10mm tube
D2 1.232 .458 10mm tube
D3 1.930 .448 10mm tube
D4 2.734 .4395 10mm tube
D5 3.585 .4325 10mm tube
D6 4.488 .423 10mm tube
D7 5.248 .430 10mm tube
Antenna Plots
Fantastic Azimuth plot of this 9el 144MHz OWL Yagi
The Elevation plot is really clean too. A quiet antenna compared with most!
Measurement taken with coaxial stub inserted within the software 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.
As always, or if you have difficulty at all, please Email me!
Justin G0KSC