The old Standard Horizon depth sounder
that came with my boat gave up the ghost a couple of years ago. The transducer seems to be a dual frequency, since there are four wires. I didn't want to pull the boat to install a new transducer, so I called Standard (which, if memory serves, is now Raymarine). Their engineer
told me the transducer in nothing more than a speaker and any transducer would work, so I replaced the display with a cheap
and hooked up two of the transducer leads and, lo and behold, it worked. Well, now the Lowrance died and I'm going to get a real depth sounder
. I can get a Raymarine
ST40 without transducer and would like to use the old transducer. Does anyone have any wisdom on this subject?