Performance Data on Hermes Oscillators Obtained by APL for Frequency and Time Reference in the APL Tracking Stations and the Atomic Frequency Standard Facility

摘要

A report is made on the performance of the Hermes Type 101C precision 1 mc oscillators as frequency and time reference standards for TRANSIT tracking stations, and for use in the atomic frequency facility. The tests were performed on the Hermes Type 101C ultra-stable oscillators using the Atomichrons as the primary standard of frequency. Each oscillator was set several days after initial warm up to 74 parts in 10 to the 10th power below the 1 mc output of Atomichron S/N 101, which corresponds to the mean frequency of the WWV standard frequency system. A record of the frequency drift was obtained daily for each oscillator. The power available to each oscillator was held at 117.5 volts 60 cycle by a line voltage regulator. The temperature of each oscillator was maintained as near that of the air conditioned room temperature (80F) as possible by mounting each oscillator on an open shelf with the corresponding oscillator power supply located on a shelf about two feet above its oscillator. Power interruptions to these oscillators have been minimized by operating them on an APL emergency power circuit. This circuit brings up power from a standby motor generator set within 3 seconds of a power failure. The low signal-to-noise ratio of the output signal limits the application of the Hermes frequency standard as it may produce poor spectral purity in common multiplier circuits. (Author)