Here is how to correctly connect an old 200 Khz transducer to a new Raymarine ST-60 depth display. Your transducer will work very well wired this way and can buy you time until a haul out. Shield goes to the black socket and the center conductor goes to the blue socket.
For the sake of keeping a back up I am still using the now 31 year old transducer despite having the new one completely installed up to the back of the display, and ready at a moments notice. It's always nice to have a back up.
While I am not recommending this as a primary installation it's a good way to get you through until a haul out. This of course if it was your display that failed and not the transducer.
Because I have both transducers wired and installed it has given me an opportunity to compare both transducers side by side. They perform identically down to within 0.1 feet. Both also perform at about the same response speed and are equally as fast, or at least no discernible response time difference. Not bad for a 31 year old transducer...