Old Transducer w/ New Display?

[hriehl1]

I removed a very old mechanical-dial style depth display from my boat that I was told did work "some of the time". I have not (yet) removed the bronze thru-hull transducer with the 2 wire leads and am wondering if this older transducer may work with only a new digital display (assuming the problems with my old unit were more likely the mechanical-dial display, not the transducer).

I see transducers come (generally) as 50kHz and 200kHz or dual frequency. Any ideas on the whether I can avoid replacing the old transducer and just get a new igital display unit? Or where there is a good web resource on this? I've spent the better part of 2 hours trying to research an answer without luck, though it does seem some depthfinders are sold as separate display and transducer units.

Thanks for any help you can provide.

[Maine Sail]

If it's a 200kHz transducer it will likely work with Raymarine and some others that are 200kHz. The center conductor of the coax cable is hot and the shield becomes ground. To confuse everyone the new Airmar transducers are often three wire; hot, ground and shield. When using an old coax transducer just make the center conductor hot and the shield the ground. On the ST-60 you just ignore the shield input and used ground and hot and it will work fine.

There were very few older 50kHz transducers unless for fish finders. Most of the old ones for depth only were 120, 200 or 210 kHz. If it is a 120 or 210 it won't work well with a newer digital read out. I am using a 31 year old Radarsonics 200kHz transducer with a new 2010 Rayamarine ST-60.. I also have the Raymarine unit mounted as a shoot through for back up.

[Triton106]

It worked for me when I replaced the old display (the size of a toaster oven) with a Hawkeye display unit (the size of a hockey puck). The wiring is very simple as you have noted (two wires). I recently switched to an inhull type transducer by Airmar and the Hawkeye display unit is still compatible. I have not yet removed the old thru-hull transducer which I plan to do next spring when I haul Blossom out of the water for a bottom rehab.

[Al]

Anyone know what kind of transducer the old Datamarine units used? Mine works, but the display is small and my eyes are getting older. I'd love to swap it out and put in a display with larger numerals.

[Maine Sail]

Anyone know what kind of transducer the old Datamarine units used? Mine works, but the display is small and my eyes are getting older. I'd love to swap it out and put in a display with larger numerals.

Mostly they used Airmar transducers with coax cable and RCA male connectors on the ends. I think for a period of time they even used some Radarsonics transducers and those should be 200kHz. Some of the Datamarine transducers were 120kHz and some were 200kHz..