Rca1948FrequencyModu.. - The New Jersey Antique Radio Club

INTERMEDIATE-FREQUENCY VALUES 249causing the interference. This is so because spurious responses willbe caused mainly by strong signals, and a condition which will permitinterference from any one of three undesired signals will be threetimes as liable to interference as one where there is possibility ofspurious rsponse from only one undesired signal. In the latter casethe undesired signal might be too weak to cause a spurious response,whereas in the former case, if any one of the three undesired signalsis strong enough a spurious response will occur. It is further assumedthat tuning is continuous between 42 and 50 megacycles, but thatsignals are confined to definite channels.LetS = signal frequency= oscillator frequency/ = intermediate frequencyT = tune frequencyM = signal-harmonic orderAT = oscillator-harmonic orderThen, for spurious response to occur,MS±I= NOT = 0±IMS±I = NT± NIM= T