The germanium transistor for instance, thermionic valves (“tubes”), helical-scan ... via Wikimedia Commons A shadow mask colour CRT has three electron guns, one for red, one for green, and ...

If you’re old enough to remember Cathode Ray Tube (CRT) Televisions ... which led to a brighter picture. All color TV’s shoot three electron guns at a phosphor screen. Typical color TVs ...

A CRT monitor (Cathode Ray Tube) is a glass vacuum tube ... or blue to create millions of colors; the cathode projects three electron guns, one each for red, green, and blue phosphor dots.