The Hewlett-Packard Model 844 3A Tracking Generator/Counter was designed to be used in conjunction with the Hewlett-Packard 8553/8552 Spectrum Analyzer. The Tracking Generator provides a cw signal which tracks the frequency tuning of the spectrum analyzer. As implied by the instrument name, the model 8443A also includes a counter section. The counter section may be used to count the output frequency of the tracking generator or the frequency of signals generated by external sources (up to better than 120 MHz). A rear panel connector provides BCD data output from the counter section for use in external equipment such as a recorder. The time base for the model 8443A counter section is a stable oven-contained, crystal-controlled 1 MHz oscillator. Provisions are made to use an external 1 MHz source for the time base if a frequency standard is available. An output from the internal 1 MHz source is also available for use in external equipment if desired.