What Happened to Selsyns? The Devices That Transmitted Position Before Digital Encoders Took Over

What Happened to Strowger Switches, the Machines That Routed Telephone Calls Before Electronics?

What Happened to Magnetic Bubble Memory Before Semiconductor Memory Took Over?

What Was Magnetic Core Memory and How Did It Store Data Before Semiconductor RAM Took Over?

What Happened to Mechanical Choppers That Amplified Tiny DC Signals Before Transistors Took Over?

What Happened to Carbon-Composition Resistors in America’s Radios and Early Electronics?

Why Rotary Converters Disappeared From America’s Subways and Power Systems

Why Unijunction Transistors Disappeared From Modern Timing and Trigger Circuits

The Rise and Fall of Quartz Crystal Tuning Before PLL Synthesizers Took Over

The Rise and Fall of Magnetrons Before Solid-State Radar Took Over

The Rise and Fall of Traveling-Wave Tubes Before Solid-State RF Took Over

The Rise and Fall of Klystrons Before Solid-State RF Took Over

The Rise and Fall of Magic Eye Tubes Before Transistor Radios Took Over

How Voltage-Regulator Tubes Stabilized Electronics Before Zener Diodes Took Over

How Mercury-Arc Rectifiers Converted AC to DC Before Silicon Changed Everything

How Mercury Switches Quietly Controlled American Homes Before Electronics Took Over

How Dekatron Tubes Counted Electronically Before Transistors Took Over

How Mechanical Vibrators Powered Car Radios Before Transistors Took Over

How Magnetic Drum Memory Stored Early Computer Data Before Core Memory Took Over

The Rise and Fall of Cadmium-Sulfide Photocells Before Silicon Sensors Took Over

How Crystal Detectors Made Early Radio Possible Before Vacuum Tubes Took Over

How Thyratrons Controlled High Power Before Solid-State Electronics Took Over

The Rise and Fall of Neon Indicator Lamps Before LEDs Took Over

How Magnetic Amplifiers Controlled Power Before Transistors Took Over

The Rise and Fall of Mercury Delay-Line Memory Before Core Memory Took Over

The Rise and Fall of Dekatron Tubes Before Transistors Took Over

The Rise and Fall of Vacuum Fluorescent Displays Before LCD and OLED Took Over

How Variable Capacitors Tuned America’s Radios Before Digital Tuning Took Over

The Rise and Fall of Relay Logic: How Early Computers Clicked Before Transistors

How Selenium Rectifiers Powered America Before Silicon Diodes Took Over

How Nixie Tubes Lit America’s Labs Before LEDs Took Over

The Rise and Fall of Wax-Paper Capacitors in America’s Radios and TVs

How CRT Television Ruled America—Until Flat Screens Changed Everything

How Germanium Powered the First Transistor Radios Before Silicon Took Over

The Rise and Fall of Vacuum Tubes: The Technology That Powered Early America