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G0KSC SC14411L 11el 144Mhz Yagi
OWA Yagis

G0KSC SC14411L 11el 144Mhz Yagi

Gain
15.78 dBi
F/B
24.01 dB
Elements
11
Specifications

Performance

Gain
15.78 dBi
Front-to-back
24.01 dB
Elements
11
Dimensions

Element dimensions

Element dimensions (parsed from legacy body — check before publishing)

Element Position Note
Ref 0 mm parsed from legacy body — confirm position vs length
D2 1010 mm parsed from legacy body — confirm position vs length
D3 1707 mm parsed from legacy body — confirm position vs length
D4 2503 mm parsed from legacy body — confirm position vs length
D5 3361 mm parsed from legacy body — confirm position vs length
D6 4235 mm parsed from legacy body — confirm position vs length
D7 5124 mm parsed from legacy body — confirm position vs length
D8 6050 mm parsed from legacy body — confirm position vs length
D9 6795 mm parsed from legacy body — confirm position vs length
Modelled performance

Plots

About this design

G0KSC SC144011L 11el 144Mhz Yagi Antenna with a 6.8 Metre Length Boom

This is a good wide band Yagi optimised for 144 to 144.600Mz. It has a mid-sized length boom of 6.8 metres and therefore can be made from a single piece 1.25 inch square tube section. Boom Support will be required with by guy wire or an additional 1.25 inch boom length bolted to the bottom of the main boom and covering 4 metres (2 metres either side of the boom centre.

Remember, this is a very wide band Yagi although it only has 11 elements it provides good forward gain. Performance of this antenna is very good with maximised radiation efficiency and very low loss. Take a look at the images below.

The SC14411L at WB9WOZ - Bruce has an 18el LFA for 430MHz directly below it

Dimensions in Metres

Element spacing:

  • Ref =      0

  • Driven = .374

  • D1 =      .535

  • D2 =      1.010

  • D3 =      1.707

  • D4 =      2.503

  • D5 =      3.361

  • D6 =      4.235

  • D7 =      5.124

  • D8 =      6.050

  • D9 =      6.795

Element sizes per element half:

  • Ref =       .508

  • Driven =   .506

  • D1 =        .478

  • D2 =        .4635

  • D3 =        .452

  • D4 =        .4445

  • D5 =        .437

  • D6 =        .433

  • D7 =        .4265

  • D8 =        .4235

  • D9 =        .4355

Performance figures @ 144.300Mhz:

  • Froward Gain: 15.78dBi free space 

  • Front to Back: 24.01dB

  • Radiation angle at 10 Metres above ground: 3 degrees

Element diameter:

Each element is made out of single piece 1/2 inch (12.7mm) aluminum tubing Each element half length needs to be doubled in order to gain your total element size. No difference is length needs to be calculated for the 1inch or 1.25 inch boom as the elements sit high enough above the boom for the boom to have no influence.

NOTE:

You can build this antenna with 13mm diameter tubing using the same parameters above. Slightly higher front to back ratio and forward gain will be seen along with a narrower SWR curve.

For construction information see 'G0KSC insulators' and the UKSMG article from the main menu on the home page.

Antenna layout, how it will look

Super clean, low-noise pattern

A Symmetrical, low-noise elevation plot too

SWR Plot nice and low.

Enjoy the antenna and please send photos!