G0KSC SC0606L 6el 50Mhz Yagi Antenna with a 6.75 Metre Length Boom

Updated June 2010

Please read the whole page, there are several versions of this antenna listed. If you do not the the diameter tubing you need to have this in or require tapered elements, Email me!

This antenna is not recommended for use in noisy city locations due to the elevation pattern. This is not a fault with this antenna, it is a characteristic of this boom length/ Wavelength

This antenna has been redesigned and represents what I beleive to the the 'ideal boom length' for an OWA direct feed 50Ohm Yagi. This can be seen in the model in the super flat SWR, the high levels of F/B ratio along with the excellent gain and pattern.

The model below is designed with 12.7mm / 1/2 inch elements and a 12mm element version. If you require a version of this antenna with another diameter wire, Email me and I will remodel. It is NOT POSSIBLE to simply resize the elements when using a different diameter wire and get the best performance in my opinion, I remodel the whole antenna each time. Element positions also need to change for the ideal antenna to be achieved again. Please read all the way down this page, there are other versions of this antenna using tapered elements too. As I have more requests, I will remodel in other element diameters and tapers and pulbish those too.

Fabio IZ3GFZ built the SC0606L for 50MHz

Dimensions in Metres - all tubing 1/2 inch or 13mm diameter, mail for other sizes and tapered elements

Element spacing:

• Ref =      0
• Driven =  .690
• D1 =       1.084
• D2 =       2.535
• D3 =      4.525
• D4 =      6.150

Element sizes per element half:

• Ref =       1.484
• Driven =   1.4625
• D1 =        1.380
• D2 =        1.3445
• D3 =        1.3295
• D4 =        1.3115

Performance figures @ 50.150Mhz:

• Froward Gain: 11.71dBi free space
• Front to Back: 21.70dB
• 1:1.1 SWR B/W 500Khz

Dimensions in Metres - all tubing 12mm

Element spacing:

• Ref =      0
• Driven =  .690
• D1 =       1.084
• D2 =       2.535
• D3 =      4.525
• D4 =      6.150

Element sizes per element half:

• Ref =       1.485
• Driven =   1.4635
• D1 =        1.381
• D2 =        1.3455
• D3 =        1.3305
• D4 =        1.3125

Performance figures @ 50.150Mhz:

• Froward Gain: 11.69dBi free space
• Front to Back: 21.44dB
• 1:1.1 SWR B/W 500Khz

Azimuth Plot

Elevation Plot

This fantastic antenna at 15m up

An Excellent SWR to go with the fantastic pattern!

G0KSC SC2805M 5el 28Mhz Yagi Antenna with a 9 Metre Length Boom

This is a good wide band long boom Yagi for 28 to 29Mhz with a real flat SWR curve that has been optimised for forward gain. It has a length boom of 8.98 metres and therefore needs to be made with a 2 piece boom of at least or 1,1/2 inch square. Boom support may be required.

Small errors in your measurements or calculations when building this antenna WILL NOT greatly affect performance due to it's non-critical design.

Dimensions in Metres

Element spacing:

• Ref =      0
• Driven = 2.116
• D1 =      3.299
• D2 =      6.004
• D3 =      8.98

Element sizes per element half:

• Ref =       2.605
• Driven =  2.547
• D1 =       2.419
• D2 =       2.377
• D3 =       2.308

Performance figures @ 28.500Mhz:

• Froward Gain: 10.78dBi free space
• Front to Back: 18.48dB
• Radiation angle at 10 Metres above ground: 15 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 3inch or 3 inch 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.