The 5/8th Vertical Antenna
The 5/8Wave Vertical
Ground Plane
The Vertical 5/8th Wave Ground Plane antenna has a gain of 6dbi over isotropic source. The center conductor goes to vertical element and the outer conductor (braided wire) goes to the horizontal element.
The Vertical Ground Plane antenna impedance averages 100 ohms at the base, and can range from 36 ohms to 200 ohms depending upon the transmission line used. Separation of the center and outer conductor where the coax or other feedline connect should not extend beyond 1" inch.
Vertical antenna's ground elements are always 1/4 wavelength in length. Always mount the Vertical Ground Plane antenna at least it's total length, or greater height above the ground or building for best results.
Note: The 5/8th wave vertical ground plane antenna requires either a impedance matching stub or a SWR Match Box to bring the SWR ratio to below 1.5:1 or better.
The natural state is over 100 ohms at the feed point.
The Vertical Ground Plane antenna impedance averages 100 ohms at the base, and can range from 36 ohms to 200 ohms depending upon the transmission line used. Separation of the center and outer conductor where the coax or other feedline connect should not extend beyond 1" inch.
Vertical antenna's ground elements are always 1/4 wavelength in length. Always mount the Vertical Ground Plane antenna at least it's total length, or greater height above the ground or building for best results.
Note: The 5/8th wave vertical ground plane antenna requires either a impedance matching stub or a SWR Match Box to bring the SWR ratio to below 1.5:1 or better.
The natural state is over 100 ohms at the feed point.
SWR Trans-match used for lowering SWR's.
The formula for a 5/8th Wave antenna is: 585/frequency in MHz.
To get the inches instead of a decimal point, just subtract the feet, and multiply 12 times the decimal point left over.
Each leg of the ground plane elements are formulated by: 234/frequency in MHz.