Description
The 5651 (CV449, QS1209) is a cold-cathode glow-discharge voltage reference valve offering a very stable 87V output, used in precision test instruments such as regulated power supplies, valve voltmeters, and measurement equipment where a stable low-current reference voltage is required.
Cold-cathode reference valves are more stable than Zener diodes in some respects and remain in use in vintage test equipment still valued for its accuracy. New Old Stock.
Supplied as a single tested valve.
