# Cross Yagi Antenna Design

What will be the effect if I add the insulation between elements and metallic boom of the cross yagi antenna (where elements from outside of the boom, instead of through boom) and in this case boom correction is required? If this is not the best way, feel free to suggest another methods for connecting the elements and metallic Boom.

"But I want to get know what happen when the elements of the antenna are from outside and insulated from the metallic boom"

The characteristics of your antenna will change:

• R component of Z at f will change
• X component of Z at f will change
• VSWR at f will change
• Antenna Resonance f(r) (where X~~0) will change
• directivity/gain-plots, -3dB angles, will change
• front/back ratio will change

How much all this is changing is cannot be determined unless a lot of very precise detail is documented, and complex simulations are ran.

Even then these would be simulations, as the real numbers are actually dependent on the mounting, height, and other environmental factors.

ANY time you change the mounting method the lengths need to be recalculated. You can google "element correction factor" and trust that their formula is correct or use an antenna simulator to do it for you. It is usually just a few percent (2%???) BUT IT WILL MAKE A DIFFERENCE!

• Thank you. But I want to get know what happen when the elements of the antenna are from outside and insulated from the metallic boom. – 0x47-sci-tech Aug 1 '15 at 6:06