HP / Agilent 5326A 50MHz Frequency Counter

The HP/Agilent 5326A is a 50 MHz timer/counter engineered for precision frequency and time interval measurements in electronics testing, calibration, and research environments. This versatile instrument delivers eight core measurement functions: frequency, period, period average, time interval, time interval average, ratio, totalizing, and scaling. It handles both burst and continuous-wave signals with single-shot time interval resolution from 0.1 ns and time interval averaging better than one nanosecond for repetitive signals.

## Technical Specifications

**Measurement Capability**
• Maximum frequency: 50 MHz
• One-shot time interval measurements: 0.1 ns minimum
• Time interval average resolution: Better than 1 ns (repetitive signals)
• Periods averaged: 1–10 selectable in decade steps

**Input Stage**
• Input impedance: 1 MΩ and 50 Ω options
• Sensitivity: 0.1 V rms sine wave; 0.3 V p-p pulse (8 ns minimum width)
• Attenuator: 10× and 100× selectable reduction
• Dynamic input voltage range: 0.1 to 3 V rms (times attenuator) + 5 V dc (times attenuator)
• Trigger level: PRESET (center, 0 V) or variable −3 V to +3 V (times attenuator); threshold band < 1.0 mV at maximum frequency
• Overload protection: 250 V rms all settings; 25 V rms on ×1 above 50 kHz

**Display and Output**
• 7-digit readout (8-digit optional)
• Automatic decimal point and unit display with each function
• Time base output: Negative pulses, +3 V to 0 V (open circuit), ~100 ns width; 10 MHz divided by TIME BASE/MULTIPLIER at rear panel BNC
• Gate output: TTL level pulses at rear panel BNC

**Gate Time Control**
• FAST position: <100 μs to ~20 ms continuously variable
• NORM position: <20 ms to ~5 seconds continuously variable
• HOLD position: Indefinite display hold

## Key Features

• High-sensitivity 50 Ω input amplifier
• Dual input impedance for flexible signal coupling
• Variable trigger threshold with fine threshold control (< 1.0 mV band)
• Remote programming options (Option 002/004)
• Temperature-compensated and oven oscillator options available
• Rack-mountable with standard flanges
• Operating temperature (rack): ≤122 °F (50 °C) ambient

## Typical Applications

Precision frequency validation, burst signal characterization, time interval analysis, ratio measurements, and repetitive signal averaging in laboratory and production test environments.

## Compatibility & Integration

Rear panel connectors for time base and gate outputs support external integration. Remote programming, digital output, and oscillator options extend measurement automation and environmental stability requirements.