A 13el 12.5 Ohm 144MHz Optimised Wideband Low impedance (OWL) Very 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 under the 'CONSTRUCTION' tab
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 16.27dBi and a boom of 8.1M long and a single antenna sky temperature of 223.1 Kelvin, this antenna will be a winner for all those seeking the most quiet antenna of this size for 2M. Excellent G/T figures too! This antenna also has an incredible 1MHz 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 Very Low Temperature antenna, ideal for EME work
Performance UK/USA Version
Forward Gain: 16.27dBi at 144.300MHz
Front to Back Ratio: 26.46dBi at 144.300MHz
Peak Gain: 16.31dBi
Peak F/B: 28.61dB
Bandwidth: 1MHz below 1.1:1
Sky Temp. TA: 223.1 Kelvin
G/T: -7.25dB
Four bay array (in metres) - 3.85V x 3.995H
Sky Temp. TA: 219.2 Kelvin
G/T: -1.28dB
Gain: 22.13dBi
Note: all G/T and sky temperature figures at 144.100MHz
Build Dimensions for UK/USA Version
Element Spacing in metres Half element Length in metres Element Notes
Reflector 0 .510 3/8 inch tube
DE .183 .486 1/2 inch tube
D1 .445 .470 3/8 inch tube
D2 .749 .4605 3/8 inch tube
D3 1.287 .4575 3/8 inch tube
D4 1.991 .4495 3/8 inch tube
D5 2.780 .443 3/8 inch tube
D6 3.621 .4375 3/8 inch tube
D7 4.499 .432 3/8 inch tube
D8 5.396 .426 3/8 inch tube
D9 6.317 .419 3/8 inch tube
D10 7.228 .411 3/8 inch tube
D11 8.104 .417 3/8 inch tube
Build Dimensions for European Version
Element Spacing in metres Half element Length in metres Element Notes
Reflector 0 .5095 10mm tube
DE .183 .487 12mm tube
D1 .445 .4695 10mm tube
D2 .749 .460 10mm tube
D3 1.287 .457 10mm tube
D4 1.991 .449 10mm tube
D5 2.780 .4425 10mm tube
D6 3.621 .437 10mm tube
D7 4.499 .4315 10mm tube
D8 5.396 .4255 10mm tube
D9 6.317 .4185 10mm tube
D10 7.228 .4105 10mm tube
D11 8.104 .4165 10mm tube
Antenna Plots
Fantastic Azimuth plot of this low temperature 13el 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
