HP / Agilent 5342A Microwave Frequency Counter

The HP/Agilent 5342A is a microwave frequency counter delivering precise frequency measurements from 10 Hz to 18 GHz across two independent inputs, with optional extension to 24 GHz. Built for laboratory, systems integration, and field applications, it combines high sensitivity, wide FM tolerance up to 50 MHz peak-to-peak deviation, and 1 Hz resolution on an 11-digit display. Input 1 covers 500 MHz to 18 GHz with sensitivity of -25 dBm up to 12.4 GHz and -20 dBm to 18 GHz. Input 2 spans 10 Hz to 520 MHz with 25 mVrms sensitivity and dual impedance selection (1 MΩ or 50 Ω). The 10 MHz crystal time base delivers short-term stability of <1 × 10⁻⁹ and aging <1 × 10⁻⁷ per month. Frequency accuracy is ±1 count plus time base error. The instrument tolerates any AM modulation index and wide FM deviation via heterodyne conversion - critical for real-world signal characterization. Optional amplitude measurement (Option 002) adds 0.1 dBm resolution across the microwave band. An 11-digit sectionalized LED display segregates GHz, MHz, kHz, and Hz readouts for clarity. Internal triggering minimizes measurement overhead. The rear panel IF output provides 25 MHz to 125 MHz down-converted signals for external analysis. HP-IB (IEEE 488) programmability is available via Option 001, supporting ASCII communication and Service Request capability. Dual inputs handle signals from DC through 24 GHz with configurable coupling and impedance termination, accommodating laboratory and system-level test scenarios without external conditioning.