(Original poster here)

For what it's worth, the Standard DS1 manual specs state:
Transmitter Frequency 207kHz
Transmitter Power 40 W min. (RMS)
Transducer Requirements 1200 pF/500 ohms

And considering all I've read here and elsewhere, I may actually try to
use the old transducer if installing the new one is too much work at
this time for me.

And thanks to Bruce in Alaska for the great post.