ARSTHACTS OF TKCFIXICAL A irri('I,l':S 1019 



Sim/Je-Frequency Signaling System for Supervision, and Dialing Over 

 Long-Dislance Telephone Trunks. N. A. Xewell' and A. Weaver'. 

 Trans. A.I.K.E., 70, Part 1, pp. 489-494, 1951. (Monograph 1841). 



The .single-freeiueiu'v sifinalinj;' system for lonjf-distanre teleplione tiuiiks 

 frees dial calls from the range ami other limitations imposed by dc signaling 

 methods. It uses alternating currents in the voice range as the signaling medium 

 and so can he used with any trunk of any length or type of line facility which 

 meets voice-tiansmission lecjuirements. The signaling recjuirements, design 

 problems, main features of the circuit and eciuipment arrangements, and the 

 operation of this .system are outlined in this i)aper. The .system described is the 

 hrst practical arrangement of its type satisfactorily to meet all the conditions (jf 

 telephone service in the Bell Telephone System. 



Experimental Information on Slip Lines. W. T. Read, Ju . pp. 129- 

 lol of Imperfections in Nearly Perfect Crystals, Wiley, N. Y., 1952, 

 490 p. Edited by W. Shockley, J. H. Hollomon, R. Maiirer and F. Seitz. 

 Symposium held at Pocono Manor, Oct. 12-14, 1950, by Committee 

 on Solids, National Research Council. 



On the (k'ometry of Dislocations. W. T. Read, Jr.' and W\ Shockley^ 

 pp. 77-94 of Imperfections in Nearly Perfect Crystals, Wiley, N. Y., 

 1952, 490 p. Edited by W. Shockley, J. H. Hollomon, R. Maurer and 

 F. Seitz. Symposium held at Pocono Manor, Oct. 12-14, 1950, by Com- 

 mittee on Solids, National Research Council. 



A Servo System for Heterodyne Oscillators. T. Slonczewski\ Trans. 

 A.I.E.E., 70, Part 1, pp. 1070-1072, 1951. (Monograph 1883). 



A constant rate of progression of frecjuency of a motor-driven heterodyne 

 oscillator is obtained by comparing its output with a frequency standard. The 

 result is fed into a servo loop which drives the motor at the proper speed. When 

 used in connection with a level recorder a linear frequency scale is obtained which 

 is more accurate than the static calibration of the oscillator. 



Metallic Rectifiers in Telephone Power Plants. D. E. Trucksess\ 

 Trans. A.I.E.E., 70, Part 2, pp 1464-1467, 1951. (Monograph 1987). 



Metallic rectifiers are a comparatively new means of converting power from 

 alternating current to direct current. Most of the component ai)paratus used 

 in the Telephone Systems operates with direct current while the normal power 

 source is alternating current. Therefore a static device without expendable parts 

 which is obtainat)le in small and laige current capacity lends itself as a means for 

 power conversion in telephone power plants. 



' Bell Telephone Laboratories 



