THRANE & THRANE TT37-134633-B POLARIZATION MOTOR SAILOR 900 VSAT. 51-2018

1. Product Identification & Overview

• Manufacturer: Thrane & Thrane (now part of Cobham SATCOM, following acquisitions).

• Part Number: TT37-134633-B

• Common Name: Polarization Motor, Polarizer Motor, Pol-Motor.

• Associated System: SAILOR 900 VSAT (Ku-band).

• Date Reference: 51-2018 (Likely a manufacturing date, batch code, or revision indicator).

2. Primary Function
This unit is the Polarization Motor Assembly for the SAILOR 900 VSAT’s antenna system. Its core function is to automatically rotate and precisely control the polarization angle of the feed horn’s wave probe inside the antenna’s Radiating Element (the “feed”).

3. Key Purpose & System Role

• Polarization Alignment: Satellite signals use either linear (Vertical/Horizontal) or circular polarization. To maximize signal strength (minimize loss) and minimize interference, the receive/transmit polarization must perfectly match the satellite’s.

• Automatic Optimization: The motor is controlled by the system’s ACU (Antenna Control Unit) or modem. It continuously makes fine adjustments to find and maintain the optimal polarization angle, a process critical during initial signal acquisition and ongoing operation.

• Impact on Performance: Correct polarization is essential for achieving the highest possible Eb/No (signal-to-noise ratio) and Tx/Rx power levels. A faulty motor leads to polarization mismatch, causing high packet loss, low data speeds, or complete link failure.

4. Technical Specifications & Characteristics

• Type: Stepper or servo motor (typically a stepper for precise positioning).

• Mounting: Integrated into the antenna feed assembly.

• Connector: Features a multi-pin electrical connector for power and control signals from the below-deck unit.

• Environment: Designed for the harsh maritime environment (corrosion-resistant materials, sealed against moisture and salt spray).

5. Common Symptoms of Failure

• System Alarms: “Polarization Failure,” “Feed Error,” or “Antenna Fault” in the SAILOR terminal interface.

• Performance Degradation: Intermittent or consistently poor link quality, even with good signal strength and pointing.

• Acquisition Problems: The system may fail to complete the satellite acquisition sequence.

• Physical: Unusual grinding noise from the antenna radome or the motor failing to move.

6. Compatibility & Replacement Notes

• Direct Replacement: This specific part number (TT37-134633-B) is the exact replacement motor for the SAILOR 900 VSAT feed.

• System Compatibility: Designed for the SAILOR 900 series. It is not directly compatible with SAILOR 600, 500, or older SAILOR SCANTAC systems without verification.

• Cross-Reference: May be equivalent to part numbers used in service databases under Cobham SATCOM.

• Important: Replacement requires the antenna to be taken out of service. Calibration and testing via the system’s built-in diagnostics are recommended after installation.

7. Typical Applications
This component is used exclusively in maritime VSAT installations:

• Commercial Shipping Vessels

• Offshore Oil & Gas Platforms and Vessels

• Mega-Yachts and Luxury Cruise Ships

• Government and Special Mission Vessels