G0KSC SC0607M 7el 50Mhz OWA Yagi Antenna with a 9.443 Metre Length Boom

This is a nice DX bean for  50 Mhz. As always it has a nice flat SWR curve and is built with in a non-critical format so any small errors you make whilst constructing will not have a huge impact on performance.

I recommend this to be built from 2 X 5 metre lengths of of 1.25inch box section.

Dimensions in Metres

Element spacing:

• Ref =       0
• Driven =  .902
• D1 =       1.417
• D2 =       3.039
• D3 =       5.11
• D4 =       7.609
• D5 =       9.443

Element sizes per element half:

• Ref =       1.472
• Driven =   1.45
• D1 =        1.371
• D2 =        1.327
• D3 =        1.302
• D4 =        1.287
• D5 =        1.283

Performance figures @ 50.250Mhz:

• Froward Gain: 12.79dBi free space
• Front to Back: 34.45dB
• Radiation angle at 10 Metres above ground: 10 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.

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.