A 7el 12.5 Ohm 144MHz Optimised Wideband Low impedance (OWL) Low Temperature 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 CONSTUCTION menu above.
Do not look at the gain figure of this antenna and compare with other 7 element 144MHz Yagis. Compare the gain, F/B and bandwidth together against other antennas of a similar boom length. With 12.73dBi and a boom of 3M long and a single antenna sky temperature of 252.9 Kelvin, this antenna will be a winner for all those seeking the most quiet antenna of this size for 2M. Class leading G/T figures too! This antenna also has an incredible 1.4MHz 1.1:1 bandwidth 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
- This is a Low Temperature antenna, ideal for EME work
The lower antenna is a 7el OWL by G0KSC at YU2MMA
Performance UK/USA Version
Forward Gain: 12.73dBi at 144.300MHz
Front to Back Ratio: 28.24dBi at 144.300MHz
Peak Gain: 12.76dBi
Peak F/B: 28.41dB
Bandwidth: 1.4MHz below 1.1:1
Sky Temp. TA: 252.9 Kelvin
G/T: -11.32dB
Four bay array (in metres) - 2.7V x 2.9H
Sky Temp. TA: 244.3 Kelvin
G/T: -5.21dB
Gain: 18.67dBi
Note: G/T and Sky temp figures always at 144.100MHz
Build Dimensions for UK/USA Version
Element Spacing in metres Half element Length in metres Element Notes
Reflector 0 .5145 3/8 inch tube
DE .127 .4925 1/2 inch tube
D1 .359 .4795 3/8 inch tube
D2 .830 .463 3/8 inch tube
D3 1.496 .4505 3/8 inch tube
D4 2.256 .438 3/8 inch tube
D5 3.001 .4245 3/8 inch tube
Build Dimensions for European Version
Element Spacing in metres Half element Length in metres Element Notes
Reflector 0 .514 10mm tube
DE .127 .4935 12mm tube
D1 .359 .479 10mm tube
D2 .830 .4625 10mm tube
D3 1.496 .450 10mm tube
D4 2.256 .4375 10mm tube
D5 3.001 .424 10mm tube
Antenna Plots
Fantastic Azimuth plot of this low temperature 7el 144MHz 12.5Ohm OWL Yagi
The Elevation plot is really clean too. A super quiet antenna, find one the same size that is more quiet!
A Super quiet antenna that is wideband? Another first from G0KSC. 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 three elements. My 'secret' to wide band low impedance antennas I now release for all to use.
As always, or if you have difficulty at all, please Email me!
Justin G0KSC