Because the CMZ 900 is long out of production, copyright enforcement has relaxed for "abandonware" in the technical sector. You can find scanned copies of the Yokogawa Gyro Compass CMZ 900 Operation Manual (Doc Ref: IM 9CMZ-01E) on maritime PDF repositories. Be cautious—many sites require credit cards. Instead, try:

When a repeater shows a heading different from the master, the manual provides the "Step Sync" procedure:

The most successful method is accessing paid or subscription-based maritime libraries:

| Parameter | Value | |-----------|-------| | Settling Time | ~3 hours from cold start | | Latitude range | Up to 80° N/S | | Follow-up speed | Up to 300°/sec | | Output | Step/synchro, NMEA 0183 | | Power | 100–230 VAC, 50/60 Hz |

Access internal trim pot (VR‑DAMP) – set for critical damping (overshoot < 5° after step change).

  • Error correction

  • Alarms

  • Maintenance (monthly)

    • ⚠️ Safety note: Do not move the ship while the gyro is settling—false heading will occur.

    | Part number (typical) | Description | |-----------------------|-------------| | CMZ900‑01 | Gyro sphere assembly (complete) | | CMZ900‑10 | Follow‑up photocell array | | CMZ900‑20 | Servo motor + tachometer | | CMZ900‑30 | Latitude compensator potentiometer | | CMZ900‑PSU | Main power board | | 902000‑F1 | Spin motor start capacitor (25 μF, 400V) | | 900‑REP‑STEP | Step repeater board |