ST 50 GPS upgrade

[bobt]

I have the full set of Autohelm ST 50 instruments including, depth, wind, log, GPS a cockpit repeater and autohelm ST 5000. The original Autohelm GPS was replaced by a Raytheon mushroom but the display is still the original Autohelm ST50 GPS. This is very unuser friendly compared to the modern instruments. It is also very unreliable. I want to upgrade the GPS but have had conflicting advice on whether any other make other than Raytheon -say the Raytheon 300 - would integrate fully with the autohelm and the other instruments.
Would for example the Garmin 128 or 152 do the trick?

 

[pandroid]

Yes. I've got the same setup as you with a Garmin 128. The only exception being that my Autopilot is a ST6000+ which uses a Type 100 course computer. Assuming the ST4000 software is similar, and you have a unit with a NMEA port on it (the current 4000 does) then you simply connect the NMEA output of the garmin to the NMEA input of the pilot, and set the ST50 GPS display to be a repeater. Note that if you forget to switch the GPS on, the ST50 repeater alarm goes off repeatedly. I've added a Pathfinder Radar/Plotter to my setup and you can now define waypoints on either the Radar or the Garmin and the pilot sees either. It all works seamlessly