Deals with measurements on diversity equipment used for making two or more receivers at a radio-relay station suitable for diversity reception. Diversity equipment is assumed to comprise the circuit for switching and/or combining the diversity channels, excluding the diversity channel equipment itself i.e. transmitters, receivers, modulators, demodulators, etc., although these may also be involved in the measurements. Measurements on twin-path and hot stand-by equipment which are not treated in Part 2, Section Two of the publication are also considered in this section. However, measurements related to the properties of the switch and of the switching process, which are applicable equally to stand-by channel switching equipment and to diversity, twin-path and hot stand-by equipment, will be covered by reference to Part 2, Section Two.