Antenna Calculator

Here are some simple antenna calculators

Simple Dipole Calculator

A useful and fundamental measurement in radio antenna work is the "half wavelength". We must know how to calculate it. It gives the desired physical length of an antenna for any operating frequency.

Enter the Desired Centre Frequency in MHz
i.e. 3.765 MHz

Total overall length of the dipole will be Feet
|---------------||----------------|

Each leg of the dipole will be Feet
|---------------||----------------|

The half-wave dipole is one of the most important and commonly used antennas and is very simple to construct. The length of a dipole is the main determining factor for the operating frequency.

For the dipole legs use an insulated copper wire of 14 gauge or heavier. Remember to make the legs slightly longer than the calculated length to allow for wrapping around the end insulators.

Use 50 ohm cable such as RG58, RG8X, RG8, RG213, or 75 ohm cable such as RG11, RG59, RG6 or 75 ohm twin ladder line to feed the centre of the dipole.

Be sure to solder the feed cable to each leg of the dipole for good electrical contact because the centre of the dipole is a high-current low-voltage point. It is also a good idea to provide some strain relief which can be a simple matter of wrapping the feed cable once around the centre insulator and securing it with a tie-wrap.

Simple Vertical Calculator

3 element beam Calculator

Simple J Pole Calculator

Enter desired frequency in MHz

A (Long sect) length: feet, in, metres

B (Short sect) length: feet, in, metres

C (Feed point) length: feet, in, metres

D (Spacing) length: feet, in, metres

Inside (spacing) dimensions are metal to metal measurements, NOT center to center.