I think You have to remember the brand of the device because of the
frequency. Modern sounders work with 200 kHz, 50 kHz or both. If you now the
brand of your sounder or transducer, you can get the information You need.
I`m not really sure, but most of that tradidional echosounders with that
rotating disk work with 200 kHz.
I myself bought an old used device of that kind, brand was rather unknown
and connected it to a new transducer of 200 kHz.

Juergen

"Wethead" schrieb im Newsbeitrag
...

I am inexperienced, so cut me some slack.

I have this 28' sailboat that has an older depth sounder, the kind with a
red light that moves in a circular pattern around graduated markings.
Sorry, I don't remember the brand, and the boat is 2000 miles away right
now. The sounder is unreliable and difficult to read. It uses a
through-hull tansducer that is heavily glassed into the hull. I would like
to replace the unit with something more modern and easier to read. The
question is, is it at all possible to use the existing transducer, or do I
have to buy and install a new one? Is a transducer a transducer, or are
they brand or unit or type specific? Manufacturer's seem to give no
information on this. I'd rather use the existing transducer, of course.

Any help would be greatly appreciated.

Wethead