Autohelm St 50 question

[Pagetslady]

Hi my AH St 50 echo sounder has stopped giving me depth, just 00 I think it is the Transducer as the speed still works and the light works. I have replaced the transducer once possibly 7 years ago with an "in hull" one and it has worked fine until a few weeks ago, I do have a fishfinder but this is a heavy draw on amps so would like to buy a new transducer to fit where the existing one goes but I can't seem to locate one there is no name on it but its about 2.5 " in dia and 1.5 " deep i have a pipe glassed into the hull which takes it snugly with a little oil to maintain connection with the hull. The connection is just two wires to the instrument head. Also anybody know whether it will transmit NMEA or will it use Seatalk.
Mike

 

[alan17]

Echo sounder transducer

Raymarine transduced is usually mounted through the hull so the face is in direct contact with water. I know that the NASA unit is mounted in an oil bath and no doubt others do the same. I do not see why the raymarine one will not work in an oil bath but it is likely to have reduced sensetivity. I get my raymarine spares from Raydirect via their web site.

 

[Fr J Hackett]

If it is a Raymarine supply it will be an Airmar http://www.airmartechnology.com/

It will transmit niether seatalk or NMEA the information is decoded in the instrument head and then passed on to other instruments as Seatalk.