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Mon Mar 16 06:47:24 MDT 2020
R. M. Bozorth The Physical Basis of Ferromagnetism . . 1--39 A. M. Curtis Contact Phenomena in Telephone Switching Circuits . . . . . . . . . . . . . . . . 40--62 H. Nyquist and K. W. Pfleger Effect of the Quadrature Component in Single Sideband Transmission . . . . . . 63--73 W. P. Mason Low Temperature Coefficient Quartz Crystals . . . . . . . . . . . . . . . . 74--93 H. A. Chinn and D. K. Gannett and R. M. Morris A New Standard Volume Indicator and Reference Level . . . . . . . . . . . . 94--137 Earle E. Schumacher and W. C. Ellis Metallic Materials in the Telephone System . . . . . . . . . . . . . . . . . 138--151 L. H. Germer and K. H. Storks Technical Digests: An Interesting Application of Electron Diffraction . . 152--155 Anonymous Abstracts of Technical Articles from Bell System Authors . . . . . . . . . . 156--158 Anonymous Contributors to this Issue . . . . . . . 159--160
A. L. Matte Advances in Carrier Telegraph Transmission . . . . . . . . . . . . . . 161--208 L. G. Wade Electrical Drying of Telephone Cable . . 209--220 W. P. Mason and R. A. Sykes Electrical Wave Filters Employing Crystals with Normal and Divided Electrodes . . . . . . . . . . . . . . . 221--248 A. M. Skellett The Coronaviser, an Instrument for Observing the Solar Corona in Full Sunlight . . . . . . . . . . . . . . . . 249--261 Earle E. Schumacher and G. S. Phipps Lead--Tin--Arsenic Wiping Solder . . . . 262--266 Karl K. Darrow Nuclear Fission . . . . . . . . . . . . 267--289 E. F. Vaage A Solution for Faults at Two Locations in Three-Phase Power Systems . . . . . . 290--305 F. A. Polkinghorn A Single Sideband Musa Receiving System for Commercial Operation on Transatlantic Radio Telephone Circuits 306--335 Anonymous Abstracts of Technical Papers by Bell System Authors . . . . . . . . . . . . . 336--337 Anonymous Contributors to this Issue . . . . . . . 338--339
K. E. Gould Crosstalk in Coaxial Cables --- Analysis Based on Short-Circuited and Open Tertiaries . . . . . . . . . . . . . . . 341--357 R. P. Booth and T. M. Odarenko Crosstalk Between Coaxial Conductors in Cable . . . . . . . . . . . . . . . . . 358--384 V. E. Legg and F. J. Given Compressed Powered Molybdenum Permalloy for High Quality Inductance Coils . . . 385--406 T. Slonczewski High Accuracy Heterodyne Oscillators . . 407--420 H. W. Bode Relations Between Attenuation and Phase in Feedback Amplifier Design . . . . . . 421--454 Karl K. Darrow Analysis of the Ionosphere . . . . . . . 455--488 Anonymous Abstracts of Technical Articles from Bell System Authors . . . . . . . . . . 489--491 Anonymous Contributors to this Issue . . . . . . . 492--493
Homer Dudley The Carrier Nature of Speech . . . . . . 495--515 G. K. Burns Manufacture of Quartz Crystal Filters 516--532 J. C. Steinberg and H. C. Montgomery and M. B. Gardner Results of the World's Fair Hearing Tests . . . . . . . . . . . . . . . . . 533--562 Millard W. Baldwin, Jr. The Subjective Sharpness of Simulated Television Images . . . . . . . . . . . 563--586 W. R. Bennett Cross-Modulation Requirements on Multichannel Amplifiers Below Overload 587--610 R. A. Heising Radio Extension Links to the Telephone System . . . . . . . . . . . . . . . . . 611--646 Anonymous Abstracts of Technical Articles from Bell System Authors . . . . . . . . . . 647--650 Anonymous Contributors to this Issue . . . . . . . 651
H. F. Dodge and H. G. Romig Single Sampling and Double Inspection Tables . . . . . . . . . . . . . . . . . 1--61 M. E. Strieby and J. F. Wentz Television Transmission Over Wire Lines 62--81 J. S. Little Insulation of Telephone Wire With Paper Pulp . . . . . . . . . . . . . . . . . . 82--94 H. Blount Design and Operation of New Copper Wire Drawing Plant: Part I --- Design and Operation of High Speed Copper Wire Drawing Machines . . . . . . . . . . . . 95--110 J. E. Wiltrakis Design and Operation of New Copper Wire Drawing Plant: Part II --- Equipping and Operating the New Wire Mill . . . . . . 111--124 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 125--128 Anonymous Contributors to this Issue . . . . . . . 129--130
S. O. Rice Steady state solutions of transmission line equations . . . . . . . . . . . . . 131--178 W. W. Werring Engineering Problems in Dimensions and Tolerances . . . . . . . . . . . . . . . 179--198 W. R. Bennett Time Division Multiplex Systems . . . . 199--221 R. V. L. Hartley Steady State Delay as Related to Aperiodic Signals . . . . . . . . . . . 222--234 F. A. Cowan and R. G. McCurdy and I. E. Lattimer Engineering Requirements for Program Transmission Circuits . . . . . . . . . 235--249 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 250--252 Anonymous Contributors to this Issue . . . . . . . 253--254
Thornton C. Fry Industrial Mathematics . . . . . . . . . 255--292 C. M. Hebbert The Transmission Characteristics of Toll Telephone Cables at Carrier Frequencies 293--330 F. R. Stansel Some Analyses of Wave Shapes Used in Harmonic Producers . . . . . . . . . . . 331--339 Karl K. Darrow Forces and Atoms: The World of The Physicist . . . . . . . . . . . . . . . 340--358 Anonymous Abstracts of Technical Articles by Bell Systems Authors . . . . . . . . . . . . 359--363 Anonymous Contributors to this Issue . . . . . . . 364
Roger I. Wilkinson The Reliability of Holding Time Measurements . . . . . . . . . . . . . . 365--404 W. P. Mason Electrical and Mechanical Analogies . . 405--414 Julian Blanchard The History of Electrical Resonance . . 415--433 Earle E. Schumacher and G. M. Bouton A Rapid Visual Test for the Quantitative Determination of Small Concentrations of Calcium in Lead . . . . . . . . . . . . 434--438 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 439--441 Anonymous Contributors to this Issue . . . . . . . 442
Oliver E. Buckley The Future of Transoceanic Telephony . . 1--19 H. N. Padowicz Diamond Dies for High-Speed Drawing of Copper Wire . . . . . . . . . . . . . . 20--36 D. B. Keeling and L. E. Cisne Using Double Sampling Inspection in a Manufacturing Plant . . . . . . . . . . 37--50 Karl K. Darrow Entropy . . . . . . . . . . . . . . . . 51--74 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 75--78 Anonymous Contributors to this Issue . . . . . . . 79
Walter L. Bond The Mathematics of Physical Properties of Crystals . . . . . . . . . . . . . . 1--72 E. E. Schumacher and G. M. Bouton and G. S. Phipps The Metallurgy of Fillet Wiped Soldered Joints . . . . . . . . . . . . . . . . . 73--79 S. A. Schelkunoff A Mathematical Theory of Linear Arrays 80--107 Karl K. Darrow Memorial to the Classical Statistics . . 108--135 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 136--142 Anonymous Contributors to this Issue . . . . . . . 143
W. L. Bond A Mineral Survey for Piezo-Electric Materials . . . . . . . . . . . . . . . 145--152 L. A. MacColl The fundamental equations of electron motion. Dynamics of high speed particles 153--177 W. P. Mason Quartz Crystal Applications . . . . . . 178--223 W. L. Bond Methods for Specifying Quartz Crystal Orientation and Their Determination by Optical Means . . . . . . . . . . . . . 224--262 J. R. Pierce A Note on the Transmission Line Equation in Terms of Impedance . . . . . . . . . 263--265 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 266--267 Anonymous Contributors to this Issue . . . . . . . 268
R. B. Blackman Effect of Feedback on Impedance . . . . 269--277 K. G. VanWynen Design of Two-Terminal Balancing Networks . . . . . . . . . . . . . . . . 278--292 W. L. Bond and E. J. Armstrong Use of X-Rays for Determining the Orientation of Quartz Crystals . . . . . 293--337 G. W. Willard Raw Quartz, Its Imperfections and Inspection . . . . . . . . . . . . . . . 338--361 Karl K. Darrow The New Statistical Mechanics . . . . . 362--392 P. LeCorbeiller Electromagnetic Waves: Review of S. A. Schelkunoff's Book . . . . . . . . . . . 393--396 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 397--401 Anonymous Contributors to this Issue . . . . . . . 402
D. K. Gannett and Iden Kerney The Discernibility of Changes in Program Band Width . . . . . . . . . . . . . . . 1--10 G. W. Willard Use of the Etch Technique for Determining Orientation and Twinning in Quartz Crystals . . . . . . . . . . . . 11--51 R. A. Sykes Modes of Motion in Quartz Crystals, the Effects of Coupling and Methods of Design . . . . . . . . . . . . . . . . . 52--96 W. R. Bennett Response of a Linear Rectifier to Signal and Noise . . . . . . . . . . . . . . . 97--113 Carl R. Englund Dielectric Constants and Power Factors at Centimeter Wave-Lengths . . . . . . . 114--129 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 130--132 Anonymous Contributors to this Issue . . . . . . . 133
E. E. Mott Indicial Response of Telephone Receivers 135--150 H. J. McSkimin Theoretical Analysis of Modes of Vibration for Isotropic Rectangular Plates Having All Surfaces Free . . . . 151--177 R. A. Sykes Principles of Mounting Quartz Plates . . 178--189 A. M. Skellett The Magnetically Focused Radial Beam Vacuum Tube . . . . . . . . . . . . . . 190--202 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 203--205 Anonymous Contributors to this Issue . . . . . . . 206
W. T. Rea Effect of Telegraph Distortion on the Margins of Operation of Start-Stop Receivers . . . . . . . . . . . . . . . 207--233 R. M. C. Greenidge The Mounting and Fabrication of Plated Quartz Crystal Units . . . . . . . . . . 234--259 A. R. D'Heedene Effects of Manufacturing Deviations on Crystal Units for Filters . . . . . . . 260--281 S. O. Rice Mathematical Analysis of Random Noise 282--332 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 333--335 Anonymous Contributors to this Issue . . . . . . . 336
Thomas Shaw The Conquest of Distance by Wire Telephony . . . . . . . . . . . . . . . 337--421 Earle E. Schumacher and Alexander G. Souden Some Aspects of Powder Metallurgy . . . 422--457 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 458--459 Anonymous Contributors to this Issue . . . . . . . 460
W. A. Edson Intermittent Behavior in Oscillators . . 1--22 Richard C. Eggleston Evaluating the Relative Bending Strength of Crossarms . . . . . . . . . . . . . . 23--45 S. O. Rice Mathematical Analysis of Random Noise 46--156 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 157--158 Anonymous Contributors to this Issue . . . . . . . 159
I. E. Fair Piezoelectric Crystals in Oscillator Circuits . . . . . . . . . . . . . . . . 161--216 C. W. Harrison The Measurement of the Performance Index of Quartz Plates . . . . . . . . . . . . 217--252 E. D. Sunde Lightning Protection of Buried Toll Cable . . . . . . . . . . . . . . . . . 253--300 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 301--302 Anonymous Contributors to this Issue . . . . . . . 303
J. R. Pierce Physical Limitations in Electron Ballistics . . . . . . . . . . . . . . . 305--321 A. L. Samuel Electron Ballistics in High-Frequency Fields . . . . . . . . . . . . . . . . . 322--352 Raymond D. Mindlin Dynamics of Package Cushioning . . . . . 353--461 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 462--466 Anonymous Contributors to this Issue . . . . . . . 467
W. C. Tinus and W. H. C. Higgins Early Fire-Control Radars for Naval Vessels . . . . . . . . . . . . . . . . 1--47 A. L. Samuel and J. W. Clark and W. W. Mumford The Gas-Discharge Transmit-Receive Switch . . . . . . . . . . . . . . . . . 48--101 John Leutritz, Jr. A Wood Soil Contact Culture Technique for Laboratory Study of Wood-Destroying Fungi, Wood Decay and Wood Preservation 102--135 Elizabeth J. Armstrong X-Ray Studies of Surface Layers of Crystals . . . . . . . . . . . . . . . . 136--155 J. L. Clarke Some Novel Expressions for the Propagation Constant of a Uniform Line 156--157 K. S. Johnson Decibel Tables . . . . . . . . . . . . . 158--158 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 159--164 Anonymous Contributors to this Issue . . . . . . . 165--166
J. B. Fisk and H. D. Hagstrum and P. L. Hartman The Magnetron as a Generator of Centimeter Waves . . . . . . . . . . . . 167--348 Anonymous Contributors to this Issue . . . . . . . 349
C. S. Fuller Some Recent Contributions to Synthetic Rubber Research . . . . . . . . . . . . 351--384 G. T. Ford Characteristics of Vacuum Tubes for Radar Intermediate Frequency Amplifiers 385--407 I. G. Wilson and C. W. Schramm and J. P. Kinzer High Q Resonant Cavities for Microwave Testing . . . . . . . . . . . . . . . . 408--434 E. I. Green and H. J. Fisher and J. G. Ferguson Techniques and Facilities for Microwave Radar Testing . . . . . . . . . . . . . 435--482 T. A. Jones and K. W. Pfleger Performance Characteristics of Various Carrier Telegraph Methods . . . . . . . 483--531 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 532--536 Anonymous Contributors to this Issue . . . . . . . 537--538
S. C. Rappleye A Study of the Delays Encountered by Toll Operators in Obtaining an Idle Trunk . . . . . . . . . . . . . . . . . 539--562 F. S. Goucher and J. R. Haynes and W. A. Depp and E. J. Ryder Spark Gap Switches for Radar . . . . . . 563--602 E. Peterson Coil Pulsers for Radar . . . . . . . . . 603--615 Robert E. Graham Linear Servo Theory . . . . . . . . . . 616--651 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 652--654 Anonymous Contributors to this Issue . . . . . . . 655--656
J. H. Scaff and R. S. Ohl Development of Silicon Crystal Rectifiers for Microwave Radar Receivers 1--30 J. P. Kinzer and I. G. Wilson End plate and side wall currents in circular cylinder cavity resonator . . . 31--79 (1 plate) W. P. Mason First and Second Order Equations for Piezoelectric Crystals Expressed in Tensor Form . . . . . . . . . . . . . . 80--138 W. R. Bennett The Biased Ideal Rectifier . . . . . . . 139--169 J. A. Becker and C. B. Green and G. L. Pearson Properties and Uses of Thermistors--Thermally Sensitive Resistors . . . . . . . . . . . . . . . 170--212 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 213--216 Anonymous Contributors to this Issue . . . . . . . 217--218
H. T. Friis and W. D. Lewis Radar Antennas . . . . . . . . . . . . . 219--317 Ray S. Hoyt Probability functions for the modulus and angle of the normal complex variate 318--359 J. C. Lozier Spectrum Analysis of Pulse Modulated Waves . . . . . . . . . . . . . . . . . 360--387 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 388--393 Anonymous Contributors to this Issue . . . . . . . 394
W. M. Goodall Telephony by Pulse Code Modulation . . . 395--409 J. P. Kinzer and I. G. Wilson Some Results on Cylindrical Cavity Resonators . . . . . . . . . . . . . . . 410--445 (1 plate) Allen F. Pomeroy Precision Measurement of Impedance Mismatches in Waveguide . . . . . . . . 446--459 J. R. Pierce and W. G. Shepherd Reflex Oscillators . . . . . . . . . . . 460--681 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 682--690 Anonymous Contributors to this Issue . . . . . . . 691
L. W. Morrison, Jr. The Radar Receiver . . . . . . . . . . . 693--817 C. E. Fay High-Vacuum Oxide-Cathode Pulse Modulator Tubes . . . . . . . . . . . . 818--836 G. E. Mueller and W. A. Tyrrell Polyrod Antennas . . . . . . . . . . . . 837--851 Sloan D. Robertson Targets for Microwave Radar Navigation 852--869 D. E. Thomas Tables of phase associated with a semi-infinite unit slope of attenuation 870--899 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 900--903 Anonymous Contributors to this Issue . . . . . . . 904
L. A. Meacham and E. Peterson An Experimental Multichannel Pulse Code Modulation System of Toll Quality . . . 1--43 R. W. Sears Electron Beam Deflection Tube for Pulse Code Modulation . . . . . . . . . . . . 44--57 Winston E. Kock Metallic Delay Lenses . . . . . . . . . 58--82 W. D. Lewis and L. C. Tillotson A Non-reflecting Branching Filter for Microwaves . . . . . . . . . . . . . . . 83--95 V. C. Rideout A Note on Parallel-Tuned Transformer Design . . . . . . . . . . . . . . . . . 96--108 S. O. Rice Statistical properties of a sine wave plus random noise . . . . . . . . . . . 109--157 J. R. Pierce Noise in Resistances and Electron Streams . . . . . . . . . . . . . . . . 158--174 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 175--180 Anonymous Contributors to this Issue . . . . . . . 181--182
H. T. Friis Microwave Repeater Research . . . . . . 183--246 D. H. Ring The Measurement of Delay Distortion in Microwave Repeaters . . . . . . . . . . 247--264 J. R. Davey and A. L. Matte Frequency Shift Telegraphy -- Radio and Wire Applications . . . . . . . . . . . 265--304 S. O. Rice Reflections from circular bends in rectangular wave guides. Matrix theory 305--349 Marion C. Gray and S. A. Schelkunoff The approximate solution of linear differential equations . . . . . . . . . 350--364 W. Howard Wise Potential Coefficients for Ground Return Circuits . . . . . . . . . . . . . . . . 365--371 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 372--376 Anonymous Contributors to this Issue . . . . . . . 377--378
C. E. Shannon A Mathematical Theory of Communication 379--423 Charles Clos An Aspect of the Dialing Behavior of Subscribers and Its Effect on the Trunk Plant . . . . . . . . . . . . . . . . . 424--445 W. R. Bennett Spectra of Quantized Signals . . . . . . 446--472 H. T. Budenbom Analysis and Performance of Waveguide-Hybrid Rings for Microwaves 473--486 S. A. Schelkunoff Methods of Electromagnetic Field Analysis . . . . . . . . . . . . . . . . 487--509 Warren A. Marrison The Evolution of the Quartz Crystal Clock . . . . . . . . . . . . . . . . . 510--588 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 589--590 Anonymous Contributors to this Issue . . . . . . . 591--592
Liss C. Peterson Equivalent Circuits of Linear Active Four-Terminal Networks . . . . . . . . . 593--622 C. E. Shannon A Mathematical Theory of Communication 623--656 J. T. Muller Transients in Mechanical Systems . . . . 657--683 W. W. Mumford Maximally-Flat Filters in Waveguide . . 684--713 Manvel K. Zinn Transient Response of an FM Receiver . . 714--731 J. R. Pierce Transverse Fields in Traveling-Wave Tubes . . . . . . . . . . . . . . . . . 732--746 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 747--751 Anonymous Contributors to this Issue . . . . . . . 752
W. J. Albersheim Propagation of TE01 Waves in Curved Wave Guides . . . . . . . . . . . . . . . . . 1--32 J. R. Pierce and W. B. Hebenstreit A New Type of High-Frequency Amplifier 33--51 A. V. Hollenberg Experimental Observation of Amplification by Interaction Between Two Electron Streams . . . . . . . . . . . . 52--58 Claude E. Shannon The Synthesis of Two Terminal Switching Circuits . . . . . . . . . . . . . . . . 59--98 Sloan D. Robertson A Method of Measuring Phase at Microwave Frequencies . . . . . . . . . . . . . . 99--103 S. O. Rice Reflection from corners in rectangular wave guides---conformal transformation 104--135 S. O. Rice A set of second-order differential equations associated with reflections in rectangular wave guides application to guide connected to horn . . . . . . . . 136--156 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 157--161 Anonymous Contributors to this Issue . . . . . . . 162--163
R. A. Leconte and D. B. Penick and C. W. Schramm and A. J. Wier A Carrier System for 8000-Cycle Program Transmission . . . . . . . . . . . . . . 165--180 C. H. Dagnall and P. W. Rounds Delay Equalization of Eight-Kilocycle Carrier Program Circuits . . . . . . . . 181--195 F. S. Farkas and F. J. Hallenbeck and F. E. Stehlik Band Pass Filter, Band Elimination Filter and Phase Simulating Network for Carrier Program Systems . . . . . . . . 196--220 D. A. Alsberg and D. Leed A Precise Direct Reading Phase and Transmission Measuring System for Video Frequencies . . . . . . . . . . . . . . 221--238 J. Bardeen and W. H. Brattain Physical Principles Involved in Transistor Action . . . . . . . . . . . 239--277 H. M. Trueblood and E. D. Sunde Lightning Current Observations in Buried Cable . . . . . . . . . . . . . . . . . 278--302 W. R. Bennett and L. C. Peterson The Electrostatic Field in Vacuum Tubes with Arbitrarily Spaced Elements . . . . 303--314 T. Slonczewski Transconductance as a Criterion of Electron Tube Performance . . . . . . . 315--328 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 329--331 Anonymous Contributors to this Issue . . . . . . . 332--334
Anonymous Editorial Note Regarding Semiconductors 335--343 W. Shockley and G. L. Pearson and J. R. Haynes Hole Injection in Germanium --- Quantitative Studies and Filamentary Transistors . . . . . . . . . . . . . . 344--366 R. M. Ryder and R. J. Kircher Some Circuit Aspects of the Transistor 367--400 Conyers Herring Theory of Transient Phenomena in the Transport of Holes in an Excess Semiconductor . . . . . . . . . . . . . 401--427 J. Bardeen On the Theory of the A-C Impedance of a Contact Rectifier . . . . . . . . . . . 428--434 W. Shockley The Theory of p--n Junctions in Semiconductors and p--n Junction Transistors . . . . . . . . . . . . . . 435--489 C. B. Feldman and W. R. Bennett Band Width and Transmission Performance 490--595 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 596--598 Anonymous Contributors to this Issue . . . . . . . 599--600
F. R. Dennis and E. P. Felch Reactance Tube Modulation of Phase Shift Oscillators . . . . . . . . . . . . . . 601--607 W. W. Mumford A Broad-Band Microwave Noise Source . . 608--618 Sloan D. Robertson Electronic Admittances of Parallel-Plane Electron Tubes at 4000 Megacycles . . . 619--646 Sloan D. Robertson Passive Four-Pole Admittances of Microwave Triodes . . . . . . . . . . . 647--655 Claude E. Shannon Communication Theory of Secrecy Systems 656--715 A. P. Brogle, Jr. The Design of Reactive Equilizers . . . 716--750 Anonymous Abstracts of Technical Articles by Bell System Authors . . . . . . . . . . . . . 751--752 Anonymous Contributors to this Issue . . . . . . . 753