The HP Model 5382A Frequency Counter is a direct-counting frequency counter that has a range of 10-225MHz. Front-panel controls allow a selection of gate times and attenuation factors of the input signal. A rear-panel connector and associated selector switch allow connection of an external time base oscillator or monitoring of the internal time base oscillator. This feature allows ratio measurements to be made by the counter. When the optional temperature compensated crystal oscillator is included, the switch is not provided and the connector is used to monitor the 10MHz time base oscillator.

OPT 001: Temperature Compensated Crystal Osillator Frequency: 10 MHz (External input replaced with Oscillator Monitor Output on Option 001)