The HP 3781A Pattern Generator paired with the HP 3782A Error Detector forms a high-performance error measuring system that complements the HP 3780A Pattern Generator/Error Detector. Designed to conform with CEPT and CCITT standards, the 3781A/3782A provides four bit rates up to 50 Mb/s of the digital hierarchy in one compact system. The companion 3781B Pattern Generator and 3782B Error Detector form a dedicated error measurement system for testing and evaluating the performance of Bell digital transmission terminal and link equipment, up to and including the DS-3 level in the digital hierarchy.

Applications of the 3781A/3782A system are in R&D, field trial, and production testing, especially where automatic and remote measurement capability via the HP-IB is required. The 3781B/3782B can be used in production testing, field installation, and maintenance of the Bell digital transmission system, including PCM/TDM transmission over cable, radio, satellite, and fibre optic links. The principal application is at the DS-3 level in the Bell digital hierarchy.

ValueTronics International specializes in test and measurement equipment for telecommunications and digital transmission applications, with deep inventory in legacy PCM/TDM error measuring equipment that remains in active service across telecom infrastructure, broadcast systems, and digital radio links. Our 20,000 sq ft secure warehouse at 1675 Cambridge Drive, Elgin, Illinois holds and tests every pre-owned instrument before it ships, with technicians who understand the specific demands of error rate testing at the DS-1, DS-2, and DS-3 hierarchy levels.

Brand Heritage

Hewlett-Packard's test and measurement division was spun out as Agilent Technologies in 1999, then the electronic measurement business was transferred to Keysight Technologies in 2014. Instruments originally manufactured under the HP brand, including the 3781/3782 series, trace their support lineage through this acquisition chain.

Compare Other Models in This Series

The 3781/3782 Series consists of dedicated PCM/TDM error measuring sets built as matched pattern generator and error detector pairs. The series is split between two standards environments: the A models (3781A/3782A) conform to CEPT and CCITT standards and cover four bit rates up to 50 Mb/s of the digital hierarchy, while the B models (3781B/3782B) are designed for Bell digital transmission systems up to and including the DS-3 level.

Each pair is intended to be used together — the pattern generator injects known PRBS or WORD test patterns into the system under test, while the error detector measures error ratio, error count, error seconds, and error-free seconds simultaneously over a chosen gating period.

Each pre-owned model below is its own dedicated product page with condition-matched pricing and availability. Select the variant that matches your standards environment and the role you need it to fill in the test setup.

The primary differentiator across the family is the standards environment. The 3781A/3782A pair targets CEPT and CCITT applications with four bit rates up to 50 Mb/s, AMI or HDB3 coding, and 75 Ω unbalanced and 120 Ω balanced pseudo-ternary outputs. The 3781B/3782B pair targets the Bell digital hierarchy with interfaces at DS-1C, T2, and DS-3 cross-connect points, ternary coding and voltage levels appropriate to each hierarchical level, and a choice of four DS-3 data formats or alternatively binary ECL interfaces.

Within each pair, the pattern generator (3781A or 3781B) provides PRBS and WORD test pattern injection with jitter modulation capability, while the error detector (3782A or 3782B) provides simultaneous measurement of error ratio, error count, error seconds, and error-free seconds with a built-in real-time clock and HP-IB output. The comparison table below summarizes the configuration of each model in the family.

Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below.

Product Core & Specifications

About this used unit

• Warranty included
• Functional verification included
• Standard Calibration Upgrade Options: No Calibration Required, NIST Traceable, Z540.1 or ISO 17025 with Data, Z540.3 Guardbanding with Data.
• Note that unnecessary accessories may not be included (contact Test Architect to confirm).

Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.