This calculator is designed to give the vertical length of a quarter-wave ground plane antenna, and the length of each of the four radials for the selected frequency you have entered. The normal quarter wave ground plane antenna consists of an insulated vertical radiator and surrounded by four horizontal radials  To find the lengths of the vertical radiator, and the length of the four horizontal radials, enter the desired frequency of operation.  Click on Calculate and the lengths will be displayed in meters, feet, and inches.  Once you have finished your ground-plane, some pruning of the elements may be required to fine-tune the  VSWR component   This VSWR optimization will make the antenna perform more efficiently.  To use 1/8 wave-length radials, divide the radial length results by 2.  Do not reduce the length of the vertical radiator.  NOTE: Be sure Javascript software is installed and enabled in your browser.

Ground-Plane Dimensions Enter Center Frequency for the Antenna Mhz     Calculated Dimensions in Meters, Feet and Inches. Vertical Length (Meters) Meters Vertical Length (Feet) Feet Vertical Length (Inches) Inches  Radial Length (Meters) Meters  Radial Length (Feet) Feet Radial Length (Inches) Inches