X903-P Synchro Retransmission Unit

REF: INT-0003

SKU: INT-0003

X903-P Synchro Retransmission Unit

NMEA or step to 360:1 Synchro Converter

The X903-P is a high power synchro retransmission unit, accepting either a stepper or NMEA 0183 data signal (or both), converting them to a 360:1 synchro signal.

With new gyros systems offering NMEA 0183 data output as standard the X903-P is an ideal, cost-effective solution for older repeater systems, autopilots, and also navigation equipment that require a synchro gyro signal.

A secondary NMEA 0183 input is also available for a backup gyro or magnetic compass, which can be used in the event of the primary gyro failure.


  • Stepper and NMEA 0183 inputs
  • Options for Gyro and Anemometer Conversion
  • Switch Over for Backup Gyro / Mag Compass
  • 360:1 Synchro Output – 115V Ref 90V Phase @0.2A per phase
  • Step Down Transformer Available for Low Voltage Synchro
  • Supply Power 115/230V (Nominal)

See our NMEA 0183 range

Technical Information

The X903-P interface converts serial heading data from a modern gyro to a high-power synchro signal with a ratio of 360:1 or 360X. Applications include refitting a ship with a new gyro, whilst retaining the existing repeaters. Many older commercial synchro gyro systems have a ratio of 360:1 or 1 revolution per degree. Other ratios are catered for by the X903-X medium power model.


All valid NMEA 0183 heading sentences, which most modern gyros give as standard and will also accept a step signal of six steps per degree.


The output is generated by solid-state techniques, and the “standard” and most common output is nominally 115v (50/60 Hz) reference, 90v line-to-line maximum voltage. The X903 also has several transformer configurations for non-standard applications. The synchro output rotates through twenty-four states per revolution with zero current, software-controlled switching technique.


The X903-P additionally has an internal relay contact, which closes in a fault condition. The local alarm has to be cleared by an onboard toggle switch. Therefore, the X903-P can detect faults in the stepper or NMEA input signals, and if the synchro output has been overloaded.


Yokogawa gyros normally use a DC supply to operate and drive the synchro, but these synchros are of the same type that uses 115v/90v AC as a drive source. So the X903-P can be used to drive these synchros without any modification.


Most KURS gyros have low power repeaters similar to Microtechnica with no problem. For those KURS gyros that feed very high power repeaters and draw high current. In this case, the X903-P is limited to 3 repeaters.

For your quotation please email sales@phpstack-450254-1410198.cloudwaysapps.com

By AMI Marine

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Item Measurements
For individual component weights and dimensions please see datasheet

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