INMARSAT MARITIME G5 CONTROLLER COMMUNICATION SATELLITE CONTROLLER PC 1004845-B 18:08

• Inmarsat Maritime
• Ship Equip
• Seatel
• Schaffner
• Combo V1
• P/N: ComboV100GX
• S/N: 1014906
• P/N: Evolution X5
• 110-240Vac
• S/N: 164712
• 50-60Hz, 10A
• P/N 1004770
• SEVSAT UNIVERSAL PANEL PC 5U 12.1″ RT 1280V800WS
• Nw13A0016270
• 110/250V 50/60Hz

The INMARSAT Maritime G5 Controller is a critical component of the classic INMARSAT-A satellite communication terminal, which was the world’s first mobile satellite communications system. This unit served as the primary user interface and control system for the shipboard terminal, enabling reliable voice, telex, fax, and data communication from anywhere within the satellite’s ocean region coverage.

Overall Function:
The G5 Controller acted as the “brain” of the INMARSAT-A station. It managed the complex signaling, call setup, and system control functions required to establish a link with the COMSAT (or other partner) satellite, the Land Earth Station (LES), and ultimately, the public switched telephone network (PSTN) or other subscribers.

Key Features and Capabilities

1. Primary User Interface:

   • Alphanumeric Keyboard: For dialing numbers, entering data, and typing telex messages directly.

   • Multi-line LCD Display: Provided menu-driven prompts, status information, call progress, and system messages.

   • Function Keys: Dedicated keys for primary functions like Voice Call, Telex, Data, Reset, and Menu navigation.

2. Comprehensive Call Management:

   • Voice Calls: Initiated and managed standard satellite telephone calls.

   • Telex Communications: The core function for business and operational messaging. Included features like storing frequently used telex numbers and message drafts.

   • Fax and Data Support: When connected to external facsimile machines or data terminals (like a 2400 bps modem), the G5 controller managed the data call setup.

3. System Control and Diagnostics:

   • Antenna Control: Provided commands and status for the ship’s stabilized parabolic antenna, ensuring it remained locked on to the selected satellite.

   • Built-In Test Equipment (BITE): Allowed crew or technicians to run diagnostic routines to verify the health of the terminal, including the Below-Deck Equipment (BDE) and the Above-Deck Equipment (ADE – the antenna/radome).

   • Status Monitoring: Continuously displayed key parameters such as signal strength, satellite selection, and system faults.

4. Operational Functions:

   • Satellite Selection: Manual or automatic selection of the best satellite ocean region (e.g., AOR-W, AOR-E, IOR, POR) for optimal signal strength.

   • Land Earth Station (LES) Selection: Allowed the operator to choose the preferred ground station for routing calls, which could affect cost and service availability.

   • Charge Calculation: Some models could estimate call duration and cost based on the selected LES and service type.

   • Watchkeeping: Supported the mandatory GMDSS (Global Maritime Distress and Safety System) watchkeeping receiver for safety alerts.

Technical Specifications (Typical)

• Model Number: PC 1004845-B

• Part Number: SEO (Satellite Earth Station) identifier, often used in provisioning and logistics.

• System Compatibility: Designed exclusively for the INMARSAT-A Standard-B/M4 compatible terminal system.

• Interfaces:

  • Telephone Handset: RJ-type connector for the voice handset.

  • Telex Terminal: Data interface for an external teleprinter or telex terminal.

  • Fax/Data Port: RS-232 or similar serial port for connecting facsimile machines or data modems.

  • Control Bus: Proprietary serial connection to the terminal’s RF Unit (Below-Deck Equipment).

• Power Supply: Typically operated on 100-240V AC, 50/60Hz, with an internal power supply.

Physical Description

The unit is a desktop console, typically beige or grey, constructed from durable plastic and metal. It is designed for installation in the ship’s radio room or navigation bridge, built to withstand the marine environment (resistant to humidity and salt spray).

Historical Context and Status

Important Note: The INMARSAT-A service, and consequently the G5 Controller, is obsolete.

• Service Decommissioning: The INMARSAT-A network was officially phased out on December 31, 2007.

• Replacement: It was succeeded by digital, more efficient, and smaller systems like FleetBroadband (FB), Fleet F77/F55/F33, and VSAT services, which offer IP-based data, voice, and video.

• Current Relevance: The G5 Controller is no longer in operational service for commercial communications. Today, it is primarily found in:

  • Maritime museums.

  • Private collections of vintage telecommunications equipment.

  • Scrapyards or as a source of spare parts for non-operational systems.