F.—l.

INTERFERENCE WITH BROADCAST RECEPTION. The duties connected with the elimination of sources of interference with radio reception were actively prosecuted during the year. At the larger towns the Department has appointed officers to devote their full services to radio inspection work, including the investigation of complaints of interference with reception. These officers are in most cases equipped with motorvehicles to enable them expeditiously to cover the district usually allotted to them. The causes of interference are very diverse, ranging from large X-ray and diathermy apparatus to various forms of household and commercial appliances. Power-lines and associated equipment are responsible for the greatest number of complaints, but trams, electric motors, and complainants' own radio receivers also are responsible for a large proportion. Many complaints necessitate considerable investigation before the precise cause of the trouble is definitely located, and in some instances the application of remedial measures is a long and difficult process. However, it is pleasing to note that, as a result of action taken by the Department, manufacturers and distributors of electrical apparatus are gradually incorporating in their equipment devices to eliminate the interfering properties, and this should bring about a gradual reduction of interference from these sources. In this connection the Department greatly appreciates the action of the suppliers of the equipment concerned in undertaking the modification of such equipment entirely at their own expense for the benefit of radio reception by listeners in general. The total number of complaints received and investigated during the year was approximately three thousand.

36