X903-X Synchro Retransmission Unit

REF: INT-0004

SKU: INT-0004

X903-X Synchro Retransmission Unit

NMEA to Synchro Converter

The X903-X is a synchro retransmission unit, converting NMEA 0183 heading data into a legacy synchro signal. As standard, the synchro output voltage is 55V Reference and 45V Phase, ideal for retrofitting for older Anschutz systems. Using the optional step-up transformer allows for a higher voltage synchro output.

With new gyro systems offering only NMEA 0183 data output the X903-X is a cost-effective solution for older repeater systems, autopilots, and navigation equipment that require a synchro gyro signal.

Various synchro ratio are available – 1:1, 9:1, 10:1, 30:1, 36:1, 90:1, 180:1 and 360:1 – and can be selected at the time of installation


  • NMEA 0183 input
  • Various Synchro Ratios Selectable
  • Synchro Output – 55V/115V Ref – 45V Phase @0.2A per phase
  • Step Up Transformer Available for High Voltage Synchro Retransmission

Also available – X903-P Synchro Retransmission Unit 

The X903-X Series

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

Heading Input is from an NMEA 0183 source, which most modern gyros give as standard.


The X903-X generates an adjustable synchro voltage of a maximum 54 volts. Therefore, ideal for Anschutz repeaters (20/24v), and several other manufacturers using nominal 50 volts.

The X903-X provides a smooth rotation, and it also interpolates the rotation to 2 decimal places of a degree. A smooth synchro rotation will be achieved from gyros that output heading to more than one decimal place of a degree.

If the gyro or interface can only provide heading output to 0.1 or 1/6th of a degree the rotation will move in steps of 0.1 or 1/6th of a degree. The SX software controls the rotation speed to reduce any oscillation on the synchro receiver.


The X903-X will detect a failure of the NMEA input signal, and overload of the synchro output.

By AMI Marine

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AC 115V/220V
Item Measurements
For individual component weights and dimensions please see datasheet

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