Rca1948FrequencyModu.. - The New Jersey Antique Radio Club

394 FREQUENCY MODULATION, Volume ITHE DEVELOPMENT OF A FREQUENCY-MODULATED POLICE RECEIVER FOR ULTRA-HIGH-FREQUENCY USE*tByH. E. Thomas!RCA Manufacturing Co., Inc., Camden, N. J.SummaryThis paper first describes the general considerations bearing upondesign of a frequency-modulated mobile police receiver for use in the SO- toiO-megacycle band where the channel width is restricted to UO Kilocycles.The details of developing the various circuits around these considerationsare dealt with, and the paper then proceeds with a discussion of over-allperformance and field testing. Comparative and quantitative results showvery favorable performance using a double-superheterodyne circuit withautomatic-frequency control of the second oscillator.(12 pages; 7 figures; 2 tables)* Decimal Classification: R630.3.f RCA REVIEW, October, 1941.t Now with Engineering Products Department, RCA VictorCamden, N. J.Division,DEVELOPMENT OF AN ULTRA LOW LOSS TRANS-MISSION LINE FOR TELEVISION*!ByE. 0. JohnsonEngineering Products Department, RCA Victor Division,Camden, N. J.SummaryThe development of a low loss 300-ohm parallel wire polyethylenedielectric transmission line is described. Loss curves, as well as a photographof a production run sample of the line, are included. The disadvantagesof twisted pair and coaxial lines are discussed and the developmentalspecifications for a line to eliminate these disadvantages are setforth. The remainder of the paper deals with actual development of the lineand treats with the dielectric, line conductors, and line impedance. Resultsof field test are included. This line is also used for FM reception.(9 pages; k figures)* Decimal Classification : R320.41.t RCA REVIEW, June, 1946.