G0KSC SC0605S 5el 50Mhz Yagi Antenna with a 3.411 Metre Length Boom

This is my lower performance 5el Yagi for 50Mhz and the one I use myself! It has a short length boom which is made from a single piece 1inch square tube section. No boom support will be required.

M1BTI built the SC0605S for QRP work

Dimensions in Metres

Element spacing:

• Ref =      0
• Driven =  .503
• D1 =      .753
• D2 =      2.069
• D3 =     3.411

Element sizes per element half:

• Ref =       1.494
• Driven =   1.473
• D1 =        1.392
• D2 =        1.367
• D3 =        1.327

Performance figures @ 50.250Mhz:

• Froward Gain: 10.05dBi free space
• Front to Back: 23.25dB
• Radiation angle at 10 Metres above ground: 10 degrees

Element diameter:

Each element is made out of single piece 1/2 inch (12.7mm) aluminium 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 1,1/4 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 paramteres 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.