Replacing a defective GPS antenna

Garmin GPS Antenna


Unfortunately, for boat owners discoveries of equipment failure often temper with the “Joys of Spring”. Usually when you power up your electronics for the first time, after a winter layup. It is usually the sensors and aerials that suffer the most. As a result of there permanent location outside in a very hostile environment.

One of the antennas that can fail is the GPS antenna. This can really mess up your precious sailing time where we are so heavily reliant on GPS these days. Gone are the days of the DR plot.

There are basically two types of GPS antenna. The first being the traditional passive antenna, that is literally just an aerial (with a 3v or 5v pre-amplifier inside). The second option is the “smart” GPS antenna that has the all the GPS receiver electronics built-in to the antenna. To tell which antenna you have, just check the cable or connector. A coax cable (like a TV aerial) with either a TNC or BNC (most common connectors for GPS aerials) is a traditional passive antenna. If it is a cable with multiple separately isolated wires inside or a multi pin connector, then it will be a “smart” GPS antenna.

GPS Antenna Cables+Connectors


Digital Yacht produce both a traditional Passive GPS Antenna and a “Smart” TriNav GPS Antenna. These provide perfect drop in replacements. This can be for any of the old marine GPS antennas that are currently in use on boats. Whatever the make or model, the chances are that one of these Digital Yacht antennas will be suitable.

Our Passive GPS Antenna (Part No X500.391) can work from either a 3v or 5v pre-amplifier supply voltage. It has a small FME connector to make it easy to feed the cable through the boat. We also supplu an FME to TNC adaptor which will fit most GPS units. Alternatively, you can easily get an FME to BNC adaptor if your GPS has the less common BNC connector. You can purchase this from any good electronics shop.

Our GPS160 TriNav smart GPS antenna (Part No ZDIGGPS160) has the very latest GPS receiver technology inside and with its simple two wire NMEA0183 output can be connected to a wide variety of Chart Plotters, VHF Radios, etc. including Garmin, Raymarine, Icom, Standard Horizon, Furuno, Lowrance, etc.

Both antennas feature a standard 1″x14TPI thread integral mount, so that you can mount to standard VHF brackets. For more information or to get wiring diagrams for specific makes and models of chart potters and radios, please contact us.

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Comments 10
  1. Need to replace a Raymarine Raystar 125 GPS Receiver connected to a 3-terminal NMEA 0183 Buss. Multiple devices (Raymarine AIS, VHF Radio, Furno Radar, Auto Helm) are on 0183 buss. Are inter-connection details available for the Digital Yacht 150 receiver to three (3) port 0183 Buss? Thanks – Pete (262-957-7931)

    1. Hi Pete, should be no problem driving these units from our GPS150. If you are connecting our GPS150 to a single connection NMEA Input i.e. no NMEA- connection, then you need to connect the green wire of our GPS150 to the Black wire (negative supply). I always get nervous when people say a 3 wire network, particularly in relation to Raymarine systems as their SeaTalk interface had three wires (Red, Black and Yellow) and you cannot connect an NMEA device directly to a SeaTalk network. However, you mention Furuno Radar, VHF, etc. so it must be an NMEA network.

  2. Hi, looking for a replacement GPS for a JRC 1800 (112W or 4340) do you have anything compatible please

    1. Hi Warren,

      The JRC1800 has a couple of NMEA0183 inputs, one for compass and one for GPS. Checking the NMEA0183 Sentences that the JRC1800 supports, on the JRC website, our GPS150 should work perfectly with it.

      Best regards

  3. Hi,
    despite not being very technology inclined as you might remember I have been using your AIS system with my iPad on my barge extensively since purchase five years ago, it’s brilliant. Going over the systems in the spring routine, I am wondering how to check that the external gps actually works ?

  4. Hi
    we have a navman 8120 that is not picking up a GPS signal, the antenna is 1240 with 8 pin plug. when i do a reset it tries to acquire a signal ,
    what are the chances that it is the antenna and not the internal GPS receiver,
    do you have an antenna that would work with this unit

    1. Hi George,

      From memory, I think there was a diagnostics page on the Navman to look at the NMEA0183 data coming in – it might be a menu option or perhaps a special system mode that you can boot up in by holding a key down at power up.

      If you can find this page, you will see the data coming from the Navman and I can help you to tell what is happening at the GPS antenna.

      It usually is the GPS antenna and our latest GPS160 would work with it, just need to find a pin out for the connector – is it in the manual?



      1. Hi Paul
        I found the page where you can see the satellite details, I also found out that the cable was the problem and managed to fix it! so relieved ! cheers.

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