CONTENTS

DefinitionsOscillators Defined.and ParametersA Second Exampleof Oscillators which cannot be Classified as an Oscillator 1

.The Buzzer. Significance of Mechanical Motion. Weight and Spring System . Friction. Simple Harmonic Motion. Analogy between Certain Mechanical and Electrical Quantities. Concept of Energy Interchange. The Pendulum. Source of Restoring Force in Pendulum. Effect of Weight in Pendulum. Electrical Analogy of Pendulum Bob. The Balance Wheel. Repetitive Shock Excitation. Basic Parameters of Oscillators. Important Implications of Fourier Theorem. The D-C Component in an Oscillatory Wavetrain .Effects of Harmonics. Frequency and Phase Modulation .. Amplitude Build-up at Resonance. Performance Parameters of Oscillators. Questions and Problems

2. ComponentsParallel- Tuned andL-C Circuit.Characteristics Losses in a ofTank Oscillators Circuit. Characteristics of "Ideal" L-C 22

Resonant Circuit. Negative Power. Performance of Ideal Tank Circuit. Resonance in the Parallel- Tuned L-C Circuit. -Capacitance Relationships for Reson- ance .Practical Tank Circuits with Finite Losses. Figure of Merit, "Q" .Physical Interpretation of Ro .Phase Characteristics of Parallel- Tuned L-C Circuit. Series- Resonant Tank Circuits. Q in Series-Tank Circuits. Resonance in Series-Tuned L-C Circuit. L-C Ratio in Tank Circuits. Transmission Lines. The Delay Line . The Artificial Transmission Line. Delay-Line Stabilized . Delay- Line Stabilized Tunnel Oscillator. Distributed Parameters from "Lumped" L-C Circuit. Resonance in Transmission Lines. Concept of Field Propagation in

Waveguides. Comparison of Lines and Guides. Resonant Cavities. Piezoelectric Property in Quartz Crystals. The Two in Quartz Crystals. The Relatively Small Tuning Effect of Holder Capacitance. Conditions for Optimum Stability .

Magnetostrictive Element. Need for Bias. Frequency-Length Relationship in Mag- netostrictive Element. The Magnetostriction Oscillator. The Tuning Fork. Appli- cations. R-C Networks as Oscillating Elements. Examples of R-C Networks Suitable as Oscillating Elements. Questions and Problems

3. OscillationThe ,.ProvokingProducing Devices.Device. Switching Actions in Tubes .Switching Actions 66

in Transistors. Power Amplification in Tubes and Transistors. Amplification . Class "A" Amplification. Class 'B" Amplification. Extention of Class "B" Concept .The Class 'C" . Action of Tank Circuit in Class "C" Amplifier. Action of Grid Current in Class "C" . Grid-Leak Bias in "C" Amplifiers. Need for Discharge Path. Resolving Apparent Conflict of Positive and Negative Grid . Neon Bulb as a Switching Device. Thyratrons .The Thyratron Inverter. Spark-Gap Oscillator. Negative-Resistance Devices. The Arc Oscillator. Concept of Dynamic Resistance. The Dynatron Oscillator. Secondary Emission. Reason for Dynatron Property of . Transitron Oscillator. Reason for Transitron Property of Negative Resistance. Function of in Transitron Oscillator . vi CONTENTS

Point-Contact Transistor as Negative-Resistance Device. Vacuum-Tube Analogy to Point-Contact Transistor. Obtaining Current Gain in Excess of Unity in Vacuum- Tube Circujt .Point-Contact Sinusoidal Oscillator. Point-Contact Relaxation Oscil- lator .Effect of Negative Resistance Region on Capacitor Storage. Positive Action in Point-Contact Relaxation Oscillators. Need for the Negative-Resistance Region. The Unijunction Transistor. The Saturable Magnetic Core. Oscillation in the Saturable-Core Circuit. The Electron Beam in Vacuo. The Magnetron. Motor Action on Electrons. The Reflex . Bunching of Electrons RetUrned to Cavity Grids. Traveling-Wave Tubes and the Backward-Wave Oscillator. Function of Helix as "Slow-Wave" Structure. Bunching of Electrons in Beam. Progressive Inctease in Bunching Density .Backward-Wave Oscillator. Questions and Problems

4. Theory of Oscillation. , ., , , , , , , , ., , , , , , , , , , The Tunnel Diode. The Two Oscillation Modes of the Tunnel Diode. Tunnel- Diode Sinusoidal Oscillators. Push-Pull Tunnel-Diode Oscillator. Cascade Tunnel- Diode Oscillator. The Class "C" Feedback Oscillator. Defining the Feedback Oscil- lator .The Question of Original Signal Voltage .The Effect of Thermal Energy upon Free Electrons in Conductors and Components. Signal Generation by Thermally Excited Electrons. A Demonstration of Oscillation Build-up From Noise Voltage . A Practical Verification of a Seemingly Abstract Concept. Initiation of Oscillation Build-up by Circuit Transients. The Effect of Fixed Bias on Spontaneous Oscillation Build-up. Effect of on Gain of an Amplifier. Physical Interpreta- tion of Infinite Gain. Feedback and Negative Resistance from the "Viewpoint" of the Resonant Tank. Basic Consideration of Phase of Feedback Signal. Feedback Under Various Phase Conditions. The Practical Obstacle to Infinite Build-up . AmplitUde Limiting by Automatic Bias Control in Class "C" Oscillators. AmplitUde Limiting in Class "A" Oscillators. Relative Linearity in Class "A" Oscillators . AmplitUde Limiting in Negative Resistance Oscillators. Divergent Effects of Grid Bias in Feedback and Negative-Resistance Oscillators. The .Modify- ing the Multivibrator to Gain Further Insight into Basic Oscillatory Process . The Blocking Oscillator. Action in Blocking Oscillator. The Squegging Oscillator .Only Relaxation are Possible with a Multivibrator .Sine-wave Oscil- lation in the Phase-shift Oscillator. The Parallel-"T" Oscillator. The Wien-Bridge Oscillator. Loading of Oscillators. DetUning Effect due to Loading: the Faraday Shield. Plate Current is Function of Effective Tank Circuit Q .The Need for Load Isolation. The Electron-Coupled Oscillator. Circuitry Considerations in the Electron-Coupled Oscillator. Additional Factors in the Performance of the Electron- Coupled Oscillator. D-C Feed Methods. Questions and Problems

5. Practical Oscillators, , ., , ., , , , , , .., , .'. ., ..., , ., , , , Three Types of Hartley Oscillators. The Type One . The Type Two Hartley Oscillator. The Type Three Hartley Oscillator. The Oscillatory Conditions Generally Existent in Practical Hartley Circuits. The Lampkin Oscil- lator .The Tuned Plate- Tuned Grid Oscillator. The Miller Oscillator. The . The . The . The Tri- Tet Oscillator .The Meissner Oscillator. The Meacham-Bridge Oscillator. Line Oscillators . Another Line Oscillator. The Magnetosttiction Oscillator. The Franklin Oscillator .The . The Beat-Frequency Oscillator. Junction-Transistor Oscil- lators .The Unijunction- Transistor Oscillator. The Regenerative Modulator. The Synchrodyne .Neutralization of R-F Amplifiers

Glossa ry , c.. :. ., .,. , , ., ..., :.. , , ., , ., , , , , , ., , ., ., ., , 199

Index 201