Interference

Interference

with broadcast reception can be caused by certain kinds of electrical machinery and appliances. It usually produces buzzing or clicking sounds. If your reception is spoilt by noises of this kind, and you are quite sure that your aerial is efficient and that your receiver is not at fault, the GENERAL POST OFFICE will help you to locate the cause and will suggest means of overcoming it. Too often the GPO is asked to help listeners who suffer interference because they haven’t put up effective aerials. Don’t give the GPO engineers unnecessary work, because in such cases they can only recommend your improving your aerial. This is specially important if you live rather far from the nearest BBC station. This advisory service, which is free of charge to wireless-licence holders, can be obtained by application at a main Post Office or to your local GPO Telephone Manager.

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The GPO

will also advise listeners whose reception is disturbed by private transmitting stations or by morse transmissions.

Two special cases

1. In certain districts where two of the programmes are very strong, a listener may sometimes notice a background of one of them when his receiver is tuned to the other. This is caused almost invariably by the effect of nearby domestic pipework, electric wiring, etc., on the aerial. The remedy is to provide a more efficient aerial erected well clear of such objects, preferably on a chimney stack.

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2. Listeners who live very close to a transmitting station may find it difficult to eliminate that particular transmission. This can in many cases be cured by realignment of the internal circuits of the receiver, which will restore its original selectivity, but when this is insufficient, a good aerial should be used, to provide strong signals of the desired programmes, and a tuned wave-filter used to eliminate the local transmission. The manufacturer of the receiver will in most cases be able to supply or specify a suitable wave-filter, which should be connected between the aerial downlead and the aerial terminal of the receiver.

Published by the British Broadcasting Corporation, 35 Marylebone High Street, London, W.1, and printed by The Broadwater Press Ltd, Welwyn Garden City, Herts.

[No. 2184/5]

BBC ENGINEERING INFORMATION DEPARTMENT // AUGUST 1951