Thanks for the replies. Mike is correct. So I guess my question can now be summed Up as how do I connect this to the back of the Ramarine A70D?
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The "sonar" connection goes to a depth transducer that works fine.
Ah, just noticed that in the first pic. In which case, why do you want to connect a 2nd transducer to the A70D ?
Just because the boat has a water Speed / temp already installed but not connected to anything. Happy to connect it to the Garmin if easier?