5/8 λ Vertical Antenna

5/8 λ Vertical Antenna

Recently I installed a CP22E Antenna which is a stacked two element 5/8 λ Vertical Antenna with a phasing coil in between. 5/8 λ Vertical Antenna has a length a little more than the usual quarter wave length vertical antenna. It has a similar low angle of radiation useful for local contacts. Hence it is a popular form of mobile antenna which can be mounted on a car. Mounting can be with a magnetic base so that it avoids drilling the car chassis, with obvious advantages when you consider resale of the car.

A matching coil is provided at the base of the antenna to give good impedance matching like that of a 3/4 λ Vertical Antenna. Under ideal conditions, 5/8 λ Vertical Antenna has a 4 dB gain over a quarter wave vertical antenna. When it is mounted on the car, the car body acts as the ground plane. 5/8 λ Vertical Antenna mounted on a car is typically used for VHF and UHF amateur radios. It can be used as an HF antenna for a base station as well. In that case, the low angle of radiation will be useful for DX contacts.