Garmin 125 GPS/Sounder - Sounder wiring

[Scorpius]

Does anybody know how to connect the sounder side of a Garmin 125 GPS/Sounder to the sounder transducer. The only manual I can find says lots about hooking up the GPS side, NEMA inputs and outputs, etc. but is silent re the depthsounder transducer. I know it's an old unit but I've been happily using the GPS side for years and I'd like to get the sounder side working as a backup to my main unit. Thanks!

[Dreamcatcher34]

You could just use ray view to your iPad and connect it tv with an hdmi cable ?