Update, got most working, 2 different cables supplied....one must be NMEA as pin out was different, anyhow, the other cable worked and I've got wind speed, and depth data converting to the P70s/Evo1, SOG is blank..guess no data out on Instrument, and wind direction is sometimes close to ST50 instrument, other times 180degrees out... gotta love Raymarine tech....
i borrowed a converter up to the 2nd last software update and no difference from old update interms of of my issues.
Now at a lost end, will contact Raymarine however the ST50 is officially not compatible with STNG.. guess some strings missing or head unit instrument output on ST's is the issue....SOG I can live without, however wind direction when using Wind vane mode does a 360degree tack until I take stop it..
Any Raymarinese translators out there?