TY - JOUR
AB - AN outstanding difficulty in the engineering development of the reception side of radio broadcasting services arises from the operation of electrical machinery. Any device in which the electric current varies produces a parasitic current in the receiving set, often causing an objectionable noise at the loud speaker or headphones. In the case of television it produces mutilation of the picture. In a paper on this subject read to the Institution of Electrical Engineers on November 22 by Mr. A. Morris, the effects produced on the receiving set by a number of domestic electric appliances were shown both aurally by gramophone records and visually by a cathode ray oscillograph. Experiments indicate that in order to ensure high quality reception the ratio of signal to noise must be at least 40 decibels. Amongst domestic apparatus the chief offenders are vacuum cleaners, electric bells, vibrators, electric wiring and high-frequency medical apparatus. Amongst small commercial apparatus are refrigerators, coffee grinders, dental drills, hair driers and clippers. Amongst large apparatus are generators, motors, flashing signs, traffic signals and overhead transmission lines. The interference due to traction plant for trains, trolley buses and electric trams is often serious. The petrol engines of automobiles and aircraft with coil or magneto ignition sometimes cause trouble. Experience shows that the amount of radio interference is becoming greater and its distribution more widespread. The remedy can be applied by the radio engineer in many cases at the receiving set, but the general level of the disturbance can be controlled only by suitable devices at the source. The present-day trouble is not primarily an electrical one, but is to find out a method of reconciling the economic aspects of the various interests concerned.
TI - Electrical Interference with Radio Reception
JF - Nature
DO - 10.1038/132848d0
DA - 1933-12-02
UR - https://www.deepdyve.com/lp/springer-journals/electrical-interference-with-radio-reception-PHImvNeqZW
SP - 848
EP - 849
VL - 132
IS - 3344
DP - DeepDyve
ER -