G0KSC SC0611L 11el 50Mhz OWA Yagi Antenna with a 17.65 Metre Length Boom
Premium commercial versions of this antenna at Innovantennas
Please read the whole page, there are several versions of this antenna listed.
If you like the look of this antenna but need tapered elements or different diameter elements, contact me
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 also a 12mm element version below. 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 possible. 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.
Enjoy the antenna and if you build, Please Send me photos!
Dimensions in Metres1/2 inch element version
Element spacing:
- Ref = 0
- Driven = .757
- D1 = 1.065
- D2 = 2.184
- D3 = 3.933
- D4 = 5.930
- D5 = 8.204
- D6 = 10.603
- D7 = 13.083
- D8 = 15.636
- D9= 17.650
Element sizes per element half:
- Ref = 1.480
- Driven = 1.4615
- D1 = 1.393
- D2 = 1.3715
- D3 = 1.343
- D4 = 1.3205
- D5 = 1.302
- D6 = 1.2855
- D7 = 1.2705
- D8 = 1.262
- D9 = 1.281
Performance figures @ 50.150Mhz:
- Froward Gain: 15.25dBi free space
- Front to Back: 33.38dB
- Stacking distances: 7.5 to 10m. 9m ideal pattern/performance balance
- Forward Gain at 9m stack: 18.06dBi
- Front to Back at 9m Stack: 29.74dB
Dimensions in Metres12mm element version
Element spacing:
- Ref = 0
- Driven = .757
- D1 = 1.065
- D2 = 2.184
- D3 = 3.933
- D4 = 5.930
- D5 = 8.204
- D6 = 10.603
- D7 = 13.083
- D8 = 15.636
- D9= 17.650
Element sizes per element half:
- Ref = 1.4805
- Driven = 1.4625
- D1 = 1.393
- D2 = 1.372
- D3 = 1.3435
- D4 = 1.321
- D5 = 1.3025
- D6 = 1.286
- D7 = 1.271
- D8 = 1.2625
- D9 = 1.2815
Performance figures @ 50.150Mhz:
- Froward Gain: 15.23dBi free space
- Front to Back: 33.02dB
- Stacking distances: 7.5 to 10m. 9m ideal pattern/performance balance
- Forward Gain at 9m stack: 18.06dBi
- Front to Back at 9m Stack: 29.74dB
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 other element diameters, please Email me.
The Azimuth plot of this fantastic 50 Ohm Split dipole antenna
The super-clean elevation plot
Elevation plot of this antenna 20m (66') above ground.
And finally the fantastic SWR curve - it does not get better than this on a 50Ohm Split dipole Yagi!
For construction information see 'G0KSC insulators' and the UKSMG article titled 'Building a Yagi' from the main menu on the home page.
