Radio and Electronics Cookbook

76

An experimental 70 cm rhombic aerial

Introduction

Most commonly used aerials can be classed as resonant or standing-wave aerials. There is another class known as non-resonant or travelling-wave. Resonant aerials, such as the dipole, are narrow-band; this occurs because resonance occurs only over a narrow band of frequencies. Travelling-wave aerials, on the other hand, can operate over a wide band of frequencies.

The rhombic is an example of a non-resonant or travelling-wave aerial. It is often employed for fixed commercial and military short-wave radio links. Made with wire, it has a diamond shape when looking down on it from above. The four corners are supported on four masts. It is a very effective aerial, and has good gain, a quality ...