I would expect that these transducers are connected to depth and speed instruments.
Yes, they are wired to a "Focus" depth and speed meter.
Wouldn't it make sense to feed the depth and speed data from the instruments to the chartplotter using NMEA 0183 rather than trying to wire the transducers directly to the chartplotter through a converter? That is a more conventional approach.
Yes, that makes sense if the transducers put out a NMEA 0183 data stream which I don't know but doubt if they do. They are 27 years old. I called Airmar and they told me there is nothing they can put in those housings to make them work with a Raymarine plotter.
Here is the link to the Raymarine ITC-5 for converting analog transducer signals to SeaTalk Ng, which is the Raymarine brand on their NMEA 2000 system. Note that the ITC-5 data has to run to a Raymarine i70 instrument in order to calibrate the transducer data. It would then be fed into the Sea Talk Ng system. However, if you do not have an i70 instrument, the ITC-5 will not work - the transducer data needs to be run directly into the instruments. That is how our system is wired - analog transducer data runs to the instruments and then the data is run throughout the system on SeaTalk Ng (including to a Raymarine E90W chartplotter and an i70 in the salon).
Thanks, I suppose that is an option. Looks like my options are...
- buy a new i70 instrument and an ITC-5.
- buy a new transducer
- do nothing and use existing speed and depth meter.