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MD71EMC: Electro-Magnetic Compass (EMC) System

SKU: MNE-0026


The MD71EMC is an Electro-Magnetic Compass (EMC) System that detects the Earth’s magnetic field directly. It then transmits the ship’s Heading over a NMEA 0183 digital connection. This is to one or more Heading Repeaters installed at any convenient location on a vessel. The EMC has no moving parts – also, unlike a TMC (Transmitting Compass) which detects the moving compass card of a ship’s compass in its binnacle.

The MD71EMC uses the latest technology to accurately process and convert the ship’s magnetic compass heading to NMEA 0183 heading data. With unparalleled accuracy at speeds of up to 70 knots and also, rates of turn up to 20° per second. Additionally, the system has been developed with improved magnetic correction facilities. This is to reduce deviation effects caused by the magnetic influence of the craft.


  • Provides Digital Heading Data from the Electro-Magnetic Compass
  • No Moving Parts
  • Unparalleled Accuracy
  • Intuitive Operator Controls. Also, with a Bright OLED display with high contrast and wide viewing angles.
  • 2x power supply inputs; 2x NMEA 0183 data channels output.
  • Correction of Magnetic Deviation and Variation
  • Automatic Calibration
  • A Backup or an Alternative to a Gyro


  • Provides a digital NMEA heading output to drive a Heading Repeater (or other devices) at a convenient location.
  • A solution for when the size of the craft makes it physically impossible or financially imprudent to install a gyro.


Increasingly, Maritime Authorities are

accepting the use of Transmitting Heading

Device (THD) Systems onboard vessels.

Marine Data offers two types of THD system:

  • A system which senses the angular position of a ship’s magnetic compass card; known as a Transmitting Magnetic Compass System (TMC)
  • A system which directly senses the Earth’s magnetic field; known as an Electro-Magnetic Compass System (EMC)

By Marine Data

Additional information

Item Measurements

MD71THD: H 96; W 96; D 35 (mm); 0.50 kg
MD97CSP: L 146; W 64; D 41 (mm); 0.35 kg
MD53A/B: H 166; W 142; Ø 123 (mm); 1.00 kg
Excludes cables & connectors


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Item Measurements

MD71THD: H 96; W 96; D 35 (mm); 0.50 kg
MD97CSP: L 146; W 64; D 41 (mm); 0.35 kg
MD53A/B: H 166; W 142; Ø 123 (mm); 1.00 kg
Excludes cables & connectors


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We are able to ship to all parts of the world. Transit times vary and are usually between 2 and 5 days depending on the destination.

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