I'd rather not change my installed bronze transducer for the new plastic one. Elsewhere on the internet I have seen:
No, the frequencies are different.
No, new transducers are smart and send data not whatever the old ones sent.
Yes, that's what I did it works fine.
Any harm in trying it?
Welcome to the Raymarine Forum Larry,
You may need to learn the sonar physics involved. The Datamarine depth transducers which I am aware of were designed to transmit sonar pings using the 170kHz frequency. Raymarine's i40/i50/iTC-5 devices are designed to support processing sonar from a 200kHz analog instrument depth transducer. It is highly unlikely that these Raymarine products will report depth from a Datamarine 170kHz depth transducer. Should you not desire plastic transducers, Raymarine offers bronze thru-hull instrument transducers.
Regarding your comment about Smart instrument depth transducers, Raymarine offers both Smart and analog instrument depth transducers. As specified above, the analog instrument depth transducers are designed to be mated directly to i40/i50/iTC-5 devices. Raymarine Smart transducers are designed to process sonar signals and then transmit the processed depth value to a SeaTalkng NMEA 2000 backbone to which an i70/i70S MFID has been interfaced. The i70/i70S MFID will be responsible for assigning keel or waterline offsets and configuring depth and anchor alarms (depth triggered). The latter systems may additionally included i40/i50 instruments which may be configured to repeat offset depth values reported by the i70/i70S MFID.