is still working perfectly!
I hooked up all new electronics about 7 years ago (maybe longer-have to look in the log book?) and the old Signet transducer plugged right into the New NAVMAN depth instrument much to my amazement (that Signet had to be original 1983 or even older - how long was it sitting in a warehouse?) ...
... it reads perfectly down to about 560', which for us is just out in the bay (Commencement Bay, PNW) ... far deeper than I really need ... my only real concern is for the top 20' especially the last 10' ::))
... I still have the original Navman transducer in case it's ever needed but since transducers have NO moving parts why bother to replace or even install the new one ... try hooking up your new instrument to the existing transducer first ... you might be pleasantly surprised ... spend the time you save installing ... sailing or something else that's more fun! My cables and plug were in great shape if they weren't I would of installed the new transducer ...
Good luck ...
~ N