3CA3 Vacuum Tube

A Subminiature Diode for Precision Detection Circuits

The 3CA3 is a subminiature vacuum diode developed for compact detection and rectification applications in portable and military electronics of the 1950s. Its wire-lead construction and miniaturized glass envelope made it ideal for equipment where size and weight were critical constraints — field radios, airborne electronics, and early portable communications gear. For restorers working on this specialized equipment, the 3CA3 is an increasingly difficult part to source, and having the correct tube is the difference between a functional restoration and a shelf piece.

Tested and Ready to Install

Every 3CA3 we sell is individually inspected before it ships — checked for shorts and functionality. You receive a tube that is ready to install and perform to its original specification. The subminiature wire-lead format is consistent with the original design. One tube per order. Inquire about specific brands at a 20% premium, or ask about tested used tubes for a 20% discount.

Rare, Correct, and Ready

Subminiature tubes are specialist components — not the kind of part you find at a general electronics supplier. If your equipment calls for a 3CA3, this is the correct replacement. Source it now while stock is available and keep your restoration moving forward.

Specifications:

• Type: Subminiature diode
• Base: Wire leads (subminiature)
• Application: Detection, rectification, portable and military electronics
• Condition: Tested and inspected
• Includes: 1 tube per order
• Premium brands available: +20% (inquire)
• Tested used tubes available: −20% (inquire)

Note: The product photo is a representative example. Actual tube appearance — including label style, glass envelope shape, and getter position — varies by manufacturer and production era.