A wireless works laboratory

The paper presents details of the equipment of a laboratory devoted to the problems of broadcast reception. Among the special equipment developed are :¿Galvanometer lamps; a distribution system for battery d.c. supply; an elaborate valve tester; an audio source; a standard valve voltmeter; combined a.c. and d.c. bridge; and interchangeable high-frequency resistors. Special methods are described in connection with insulation tests of condensers; correction of wattmeter errors; measurement of amplification; self-capacity of coils and their high-frequency resistance; and keeping records.