The HP/Agilent 3785B is a microprocessor-controlled jitter generator and receiver for testing digital transmission systems up to DS-3 rates (34368 kb/s). This portable instrument generates and measures jitter on both data and clock signals while conforming to CCITT Recommendation O.171, making it essential for production, field installation, and maintenance of PCM/TDM systems across cable, radio, satellite, and fiber optic links.
## Technical Specifications
The 3785B operates on 100/120 VAC or 220/240 VAC ±10%, with total power consumption of 640 Watts. It provides DC output capabilities of 0-32 Volts DC and 0-20 Amps. The instrument accommodates up to four internal bit rates and integrates with HP-IB for bus-controlled operation and automated measurement sequencing.
## Key Features
• Generates and measures jitter via internal crystal clock or externally applied data stream
• Sinusoidal modulation provided by internal synthesizer with adjustable amplitude and frequency
• Transient-free sweeping through programmed CCITT-shaped jitter tolerance masks
• Built-in measurement filters compliant with CCITT Recommendations
• Six distinct measurement types: absolute jitter amplitude in UI pk-pk, jitter peak (positive or negative), jitter hit count, jitter hit seconds count, jitter hit-free seconds count, and maximum absolute jitter amplitude held during gating period
• Internal modulation frequencies displayed on front panel per CCITT Recommendation O.171
• External modulating signal input capability
• Ergonomic front panel layout with microprocessor control
## Typical Applications
Production testing and field verification of CEPT and Bell digital transmission terminal and link equipment. Maintenance of PCM/TDM systems deployed across diverse transmission media.
## Compatibility & Integration
Compatible with CEPT or Bell digital transmission terminal and link equipment up to the third level of the digital hierarchy (34368 kb/s or DS-3). Full HP-IB integration enables remote control and automated test sequences.
