SI-TEX External GPS Antenna for MDA-1 Transceiver

The SI-TEX External GPS Antenna is an optional antenna for the MDA-1 AIS transceiver, which also has GPS built in.

The MDA-1 has an internal GPS, so this antenna is an option rather than a requirement. It exists because an internal antenna needs the unit itself to have a sky view, and most transceivers are mounted below. Moving the antenna outside is what lets the transceiver be installed where it fits rather than where it can see satellites.

An AIS transceiver must transmit an accurate position continuously, and a weak or intermittent fix means the vessel appears in the wrong place to everyone else on the water. That makes GPS reception a safety matter on AIS rather than a convenience, unlike on a chartplotter where a brief loss is only an inconvenience. Explore more marine antennas.

• Optional, since the MDA-1 has GPS built in
• Lets the transceiver mount where it fits, not where it sees sky
• AIS must transmit an accurate position continuously
• A weak fix puts your vessel in the wrong place