Rca1948FrequencyModu.. - The New Jersey Antique Radio Club

466 FREQUENCY MODULATION, Volume Iof the discriminator circuit. To accomplish this, a meter is providedin the diode circuit.The oscillator circuit is tuned for maximum diodecurrent and isthen backed down, in the same direction each time, to70 per cent of the peak current.The use of this instrument and results of measurements are completelycovered in the paper by H. E. Roys entitledan FM Calibrator for Disk Recording Heads." 5"Experience withAcknowledgmentThe author wishes to acknowledge the helpful suggestions andadvice of E. W. Kellogg, H. E. Roys, C. M. Sinnett, and A. C. Blaneyin thiswork.References1G. L. Beers and C. M. Sinnett, "Some Recent Developments in RecordReproducing Systems," Jour. Soc. Mot. Pic. Eng., XL, 4 (April, 1943), p. 222.2F. E. Terman, "Radio Engineering," McGraw-Hill (New York), 1937,p. 360; J. B. Dow, "A Recent Development in Vacuum Tube Oscillator Circuits,"Proc. I.R.E., 19 (December, 1931), p. 2095.3V. D. Landon and K. Mcllwain, "Pender's and Mcllwain's ElectricalEngineers' Handbook (Electric Communication and Electronics)," JohnWiley and Sons (New York), 3d Ed., p. 7.4D. G. Fink, "Electronic's Engineering Manual," McGraw-Hill (NewYork) , p. 240.5H. E. Roys, "Experience with an FM Calibrator for Disk RecordingHeads," Jour. Soc. Mot. Pic. Eng., 44, 6 (June, 1945), p. 461.