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G0KSC SC2804S 4el 28Mhz Yagi
OWA Yagis

G0KSC SC2804S 4el 28Mhz Yagi

Gain
8.29 dBi
F/B
21.42 dB
Elements
4
Specifications

Performance

Frequency
28–29 MHz
Gain
8.29 dBi
Front-to-back
21.42 dB
Elements
4
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
Driven 1287 mm parsed from legacy body — confirm position vs length
D1 1776 mm parsed from legacy body — confirm position vs length
D2 3700 mm parsed from legacy body — confirm position vs length
Ref 2649 mm parsed from legacy body — confirm position vs length
Driven 2573 mm parsed from legacy body — confirm position vs length
D1 2443 mm parsed from legacy body — confirm position vs length
D2 2330 mm parsed from legacy body — confirm position vs length
Modelled performance

Plots

About this design

G0KSC SC2804S 4el 28Mhz Yagi Antenna with a 3.7 Metre Length Boom

This is a good wide band Yagi for 28 to 29Mhz with a real flat SWR curve and good F/B. It has a short length boom of 3.7 mtrs and therefore can be made from a single piece 1inch square tube section. No boom support will be required.

Dimensions in Metres

Element spacing:

  • Ref =      0

  • Driven = 1.287

  • D1 =      1.776

  • D2 =     3.7

Element sizes per element half:

  • Ref =       2.649

  • Driven =  2.573

  • D1 =       2.443

  • D2 =      2.33

Performance figures @ 28.400Mhz:

  • Froward Gain: 8.29dBi free space

  • Front to Back: 21.42dB

  • Radiation angle at 10 Metres above ground: 14 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 1, 3/4inch or 2inch boom as the elements sit high enough above the boom for the boom to have no influence.

If you are only able to obtain 1/2 inch elements in 6 metre lengths and can only obtain 5 metre lengths, join them in the middle at the insulator with a small piece of 3/8 inch tubing (600mm long) bolt the element to the insulator with 2 bolts either side of the boom.

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.