RCA 919 Phototube Photoelectric Cell 919
Discover a key piece of automation and motion picture history with this RCA 919 vacuum tube. This is not an audio or radio amplifier tube, but a gas-filled phototube—an “electric eye” designed to convert light into an electrical signal. As a New Old Stock (NOS) component, this vintage tube has never been used, offering an authentic piece of technology from an era when light was used to control machines and industrial systems. Manufactured in the USA by the legendary RCA, the 919 was an essential component in a wide range of 20th-century photoelectric sensing applications.
Tube Type & Primary Function:
The RCA 919 is a gas-filled phototube. Its operating principle is as follows:
An internal surface (the cathode) is coated with a light-sensitive material.
When light strikes the cathode, it emits electrons.
Unlike vacuum phototubes, the RCA 919 contains a small amount of inert gas. As the electrons travel toward the anode, they collide with the gas atoms, releasing additional electrons in a cascading multiplication effect.
This process of collision ionization significantly amplifies the current, making the tube much more sensitive than a vacuum phototube.
Its S1 spectral-response cathode makes it particularly sensitive to incandescent light, red light, and near-infrared radiation.
Key Features of the RCA 919 Phototube Vacuum Tube Photoelectric Cell:
Authentic New Old Stock (NOS): A genuine vintage component that has never been used and comes in its original RCA box, preserving its original factory condition.
Light Sensor, Not an Amplifier: Specifically designed to detect light and control other electronic circuits.
Gas-Filled Design: Provides high light sensitivity, making it ideal for detecting subtle changes in illumination.
Red and Near-Infrared Sensitivity: Ideal for reading optical soundtracks on vintage motion picture film and for use with incandescent light sources.
Made by RCA in the USA: A hallmark of outstanding quality and reliability from the golden age of electronics.
Rugged Construction: Featuring an octal base and a top anode cap, this tube was built for long-lasting performance in demanding industrial environments.
Technical Specifications of the RCA 919 Phototube Vacuum Tube Photoelectric Cell:
| Specification | Value |
| Tube Type | |
| Manufacturer | |
| Country of Origin | U.S.A. |
| Base | UX4 |
| Anode Connection | Top Cap |
| Spectral Response | S1 (Red/Near-Infrared Sensitive) |
| Maximum Anode Voltage | 90 VDC |
| Typical Sensitivity |
Typical Applications of the RCA 919 Phototube Vacuum Tube Photoelectric Cell:
This type of phototube was a cornerstone of early automation technology, with applications including:
Motion Picture Projectors: Its most well-known application was in 16 mm and 35 mm film projectors, where it read the variable-area optical soundtrack along the edge of the film.
Industrial Controls: Used as an “electric eye” to count objects on conveyor belts, operate automatic doors, and serve as a safety interlock in industrial equipment.
Alarm Systems: Used to detect the interruption of a light beam for security and monitoring applications.
Scientific Instrumentation: Used in densitometers, colorimeters, and other light-measuring instruments.
Light-Operated Relays and Control Circuits: Ideal for photoelectric relay systems and a wide variety of light-activated control circuits.
Package Contents:
1 × RCA 919 Phototube Vacuum Tube
1 × Original Vintage RCA Box (Box condition may vary due to age and long-term storage.)
RCA 919 Phototube Vacuum Tube Photoelectric Cell NOS USA
About RCA (Radio Corporation of America)
The Radio Corporation of America (RCA) is one of the most influential companies in the history of electronics. Founded in 1919, RCA was a pioneer in radio, television, and electronic component manufacturing. Its renowned Radiotron division produced an extensive range of vacuum tubes, from those used in consumer radios to highly specialized devices such as the RCA 919 gas-filled phototube.
Made in the U.S.A., RCA vacuum tubes are recognized worldwide for their innovation, rugged construction, and dependable performance. For decades, they set the industry standard against which other manufacturers were measured, making them highly sought after by collectors, restorers, and vintage electronics enthusiasts.
