Abstracts of Technical Articles by Bell System Authors 



Capacitors — Their Use in Electronic Circuits} M. Brotherton. This 

 book tells how to choose and use capacitors for electronic circuits. It ex- 

 plains the basic factors which control the characteristics of capacitors and 

 determine their proper operation. It helps to provide that broad under- 

 std.nding of the capacitor problem which is indispensable to the efficient 

 design of circuits. It tells the circuit designer what he must vmderstand 

 and consider in transforming capacitance from a circuit symbol into a practi- 

 cal item of apparatus capable of meeting the growing severity of today's 

 operation requirements. 



Mica Capacitors for Carrier Telephone Systems.^ A. J. Christopher 

 AND J. A. Kater. Silvered mica capacitors, because of their inherently 

 high capacitance stability with temperature changes and with age, now are 

 used widely in oscillators, networks, and other frequency determining 

 circuits in the Bell Telephone System. Their use in place of the previous 

 dry stack type, consisting of alternate layers of mica and foil clamped 

 under high pressures, has made possible considerable manufacturing econ- 

 omies in addition to improving the transmission performance of carrier 

 telephone circuits. These economies are the result of their relatively simple 

 unit construction and the ease of adjustment to the very close capacitance 

 tolerance required. 



Visible Speech Translators with External Phosphors.^ Homer Dudley 

 AND Otto 0. Gruenz, Jr. This paper describes some experimental ap- 

 paratus built to give a passing display of visible speech patterns. These 

 patterns show the analysis of speech on an intensity-frequency-time basis 

 and move past the reader like a printed line. The apparatus has been 

 called a translator as it converts speech intended for aural perception into a 

 form suitable for visual prception. The phosphor employed is not in a 

 cathode-ray tube but in the open on a belt or drum. 



The Pitch, Loudness and Quality of Musical Tones {A demonstration- 

 lecture introducing the new Tone Synthesizer)} Harvey Fletcher. Re- 

 lations are given in this paper which show how the pitch of a musical tone 



» Published by D. Van Nostrand Company, Inc., New York, N. Y., 1946. 



' Elec. Engg., Transactions Section, October 1946. 



^Jour. Acous. Soc. Anier., July 1946. 



* Amer. Jour, of Physics, July- August 1946. 



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