HP / Agilent 5384A 10 Hz to 225 MHz Frequency Counter

The HP/Agilent 5384A is a dual-channel frequency counter covering 10 Hz to 225 MHz with up to 9-digit resolution. Channel A addresses low-frequency signals from 10 Hz to 100 MHz with 15 mVrms sensitivity at 50–100 MHz and 25 mVrms at 10–50 Hz, while Channel B extends coverage to 225 MHz with 10 mVrms sensitivity at 50–200 MHz. The instrument measures frequency, period, ratio, and totalize functions using interpolar-enhanced reciprocal counting for cost-effective accuracy. A 10 MHz timebase with <3 × 10⁻⁷ per-month aging and <5 × 10⁻⁶ temperature stability over 0°C to 50°C ensures precise measurements across telecommunications, R&D, and automated test environments.

Technical Specifications Frequency Measurement

Frequency range: 10 Hz to 225 MHz

Resolution: Up to 9 digits per second

Measurement functions: Frequency, period, ratio, totalize

Counting method: Interpolar-enhanced reciprocal counting Channel A (10 Hz – 100 MHz)

Sensitivity: 15 mVrms (50–100 MHz); 25 mVrms (10–50 Hz); 45 mV pk-pk (5 ns minimum pulse width)

Dynamic range: 45 mV to 4 V pk-pk

Coupling: AC

Impedance: 1 MΩ nominal || <25 pF (X1); 500 kΩ nominal || <25 pF (X20)

Attenuator: X1 or X20; X40 below 50 Hz

Low pass filter: 100 kHz (nominal 3 dB point)

Trigger level control: ±2.5 Vdc adjustable Channel B (50 MHz – 225 MHz)

Sensitivity: 10 mVrms (50–200 MHz); 15 mVrms (200–225 MHz)

Dynamic range: 10 mV to 1 Vrms

Coupling: AC

Impedance: 50 Ω nominal

Attenuator: Manual X1 to X5 (0–14 dB nominal); Auto AGC mode

Damage level: 350 VDC + 5 Vrms AC Timebase

Frequency: 10 MHz

Aging rate: <3 × 10⁻⁷ per month

Temperature stability: <5 × 10⁻⁶ (0–50°C, referenced to 25°C)

Line voltage stability: <1 × 10⁻⁷ (±10% variation)

Optional TCXO available for enhanced stability Display

Type: Programmable alphanumeric LCD

Digits: 12-digit display with variable control (3–11 digits)

Key Features

Dual-channel architecture covers low to high RF frequencies

Extensive input conditioning with low pass filtering and manual/automatic attenuation

Half-rack width form factor for benchtop, rack-mount, or field deployment

Variable digit display blanks meaningless data for clean signal observation

Typical Applications

Telecommunications frequency verification and quality assurance

Research and development prototyping and characterization

Automated test equipment (ATE) systems integration