The Sperry Marine 65801805-4 is a specialized bearing transmission and interface printed circuit board (PCB) manufactured by Sperry Marine (Northrop Grumman Sperry Marine) in the United States. Designed for integration within Sperry marine gyrocompass distribution systems, bearing repeater units, and navigation processor cabinets, the 65801805-4 processes heading and bearing data for accurate distribution across bridge equipment.

The board converts and conditions synchro, stepper, or serial gyro signals to drive analog bearing repeaters, radar heading alignment feeds, ECDIS overlays, and autopilot feedback loops. Built with industrial-grade components and protective conformal coating, the 65801805-4 ensures continuous, noise-free heading signal transmission under demanding shipboard operating conditions.

Key Features:
• Precise Bearing Signal Processing: Converts and conditions master gyro signals for accurate distribution to remote bridge repeaters and navigation displays.
• High-Reliability Signal Isolation: Protects signal lines from ground loops, electrical transients, and electromagnetic interference on commercial vessel bridges.
• Direct Chassis Plug-In Fit: Designed for seamless installation into standard Sperry Marine gyro distribution units and navigation processor racks.
• Robust Marine-Grade Construction: Built with conformal-coated PCB traces and high-durability edge connectors to resist continuous vibration, temperature cycling, and humidity.
• Multi-Device Distribution: Capable of driving multiple bearing repeaters, radar display interfaces, and VDR heading capture feeds simultaneously.

Technical Specification

⚙️ Typical Functionality & Role

Bearing/Heading Pulse Processing: The board reads pulse signals generated by a pulse disc (encoder) on the rotating radar scanner and provides processed signals used for speed/bearing tracking within the radar’s control circuitry.
Opto-coupler Interface: Opto-couplers mounted on the rear of the board detect the pulse disc’s markings during rotation.
Link/Jumper Configuration: The board includes a jumper/link (LK1) that adjusts the tracking characteristics of the phase-locked circuitry, depending on scanner rotation speed (e.g., configured for LOW vs HIGH RPM settings).
- Example: Jumper in pins 1 & 2 for ~28 RPM (LOW), pins 2 & 3 for ~45 RPM (HIGH).