FE-5680A Rubidium Frequency Standard

The FE-5680A is a precision electronic device known as a Rubidium Frequency Standard, often referred to as an 'atomic clock.' This specific model was manufactured by FEI Communications Inc., a subsidiary of Frequency Electronics, Inc. (FEI), founded in the United States. These devices are used in high-precision telecommunications, satellite communication, and laboratory environments where stable timekeeping and frequency generation are critical.

Frequency Electronics, Inc. remains the ultimate owner and is headquartered in Mitchel Field, New York. While these units are a staple in specialized industrial and military sectors, they often appear on the secondary market for electronics hobbyists and researchers worldwide. The manufacturing for these precision instruments primarily takes place at the company's New York facilities to maintain strict aerospace and defense quality standards.