Electronics, Second Edition deals with the behavior, properties, and control of electrons. The book discusses the basis of electronics technology—the electron, electric current, conductors, semi-conductors, insulators, current flow, and the relationship between the electromotive force (e.m.f.) and current. It also explains amplitude, frequency, wavelength, phase, harmonics, modulation, and ultrasonic waves. The book describes the main components of a simple amplifier, the frequencies it can handle (20 Hz to 20 kHz, or higher depending on what it is connected to its output), or if it can drive a loudspeaker (no, but it is suitable for high-impedance headphones). It explains how signals are generated such as sine waves, square waves, pulses, sawtooth; modifying another signal can also generate a particular waveform. It also discusses the principles of radio and television, radar, microwave, the distinguishing feature of a digital circuit, as well as the operation of a remote control TV. The book is suitable for radio technicians, engineers, apprentices, hobbyists, and students of electrical engineering or electronics.