BBC R&D

Abstract

The local oscillator of a television receiver tuned to channel n can cause interference to a neighbouring receiver tuned to channel n+5. If, in modern receivers, this radiation is significantly lower than that prescribed in British Standard BS 905:1969 consideration could be given to relaxing the planning standards in areas where the problem might arise.

This report examines the ways local oscillator interference becomes apparent and describes recent measurements made to determine whether there has been any reduction in the level of radiation from modern receivers. It concludes that there has been no significant reduction. Lower levels could probably be achieved by relatively simple design changes although it is thought that there is no particular incentive once the British Standard has been met.