Formulas To Design Your Own Dipoles And Inverted Vees
Most hams are familar with the center fed, half wave dipoles and inverted vees that are very popular and easy to build. This formula will give you a starting point to make these antennas. There are several factors that affect the resonant frequency of any antenna. Some of these factors are: the height above ground, the diameter of the wire, nearby structures, the affects of other antennas in the area and even the conductivity of the soil.
If you've ever used some of the other antenna design programs you may realize that the formula for these types of antennas vary from about 476/f Mhz to 490/f MHz depending on the band and the height above ground!
Fortunately there is a
formula that can be used as a starting point in your design. For a center fed, wire dipole, this formula is 468 / frequency in megahertz. I've always cut the antenna a few inches longer which would allow me to trim the antenna in order to obtain a 1:1 match.
The inverted vee has always been about 3 - 5% shorter than a dipole at the same frequency. I used 4% as a constant in the calculation. You may change this value to any number that you like to use.
This page uses the standard formula, 468 / f MHz to calculate dipole lengths. You may change this number if you know of a better number to use as your starting point.
Enter the formula for the antenna calculation
Percent smaller for the Inverted Vee
Your dipole's total length is
Each leg of the dipole is
Your Inverted Vee's total length is
Each leg of the Inverted Vee is
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