Rca1948FrequencyModu.. - The New Jersey Antique Radio Club

A NEW EXCITER UNIT FOR FREQUENCY-MODULATED TRANSMITTERS*!ByN. J. OmanEngineering Department, RCA Victor DivisionCamden, N. J.Summary— This paper describes an exciter unit for use in frequencymodulationtransmitters. The new exciter unit is capable of producing afrequency modulated carrier of excellent linearity and low noise level. Thecarrier frequency is automatically maintained to an accuracy close to thatof a crystal-controlled oscillator, the frequency of the latter being used asa reference.T-"^HERE are two systems now in general use for producing a frequencymodulated signal which meets the Federal CommunicationsCommission's requirements for frequency modulationbroadcasting. One method, making use of phase-shift modulation, wasdeveloped by Major E. H. Armstrong. The operation of this system isshown in schematic form in Figure 1.AUDIO(-r)i,'TYV--~Z8- 28» MAX. MiO 50~ 2KC I5KC^L^— :r=*o\