A68 (replaced A67) and older thru hull transducer

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Chris,

General comments: The ax8 and ax7 MFDs feature different internal fishfinder sounder circuitry, requiring fundamentally different transducers. Please click here to view a FAQ addressing this subject. I would recommend that a CP370 be installed and interfaced to the a68 MFD. Then, the currently installed B744V transducer may be then be adapted to be mated to the CP370's Transducer socket using an 33-562-01 Transducer Adapter Cable. Alternatively, an i40 Bidata Instrument display (display-only) or i50 Tridata instrument display (display-only) may be installed onboard. Please click here to view a FAQ addressing how to adapt a 50/200kHz fishfinder transducer for use with one of these instrument displays.

Q1) 1) If I am willing to give up the fishfinder, and just want depth, is there a way to wire the A68 to the B744 directly, and run the A68 in non-chirp mode?
A1) No

Q2) Install an i40 Depth, connected to the B44/B744. This seems like a great option for me because I can mount the i40 near my line of sight and see the depth easily. It looks like the i40 depth just has three pins to connect to the transducer, and I've seen B744 as being supported. Will that work? Wiring diagram somewhere?
A2) See the general comments above addressing this subject.

Q3) Add a converter (itc5?) to convert the signal to Seatalk ng. This sounds like it would work.. I don't have a Seatalk network, though, and sound like more complication and expense than I'd like.
A3) As MFDs cannot calibrate instrument transducers and cannot assign alarms and offsets for instruments transducer, this is not an option unless an i70 MFID is also added to the system.

Q4) If #2 works, then can I assume that I could run a seatalk cable from the i40 to the A68 to display depth on A68? Not as critical but might be a nice to have in the future.
A4) As the a/c/e/eS/gS-Series MFDs do not have a communications interface supporting SeaTalk communications protocol, it would be necessary to install a SeaTalk to SeaTalkng Converter Kit to which the i40 instrument and MFD would each be interfaced. Should the option of an i50 Tridata Instrument display be exercised, then the i50 Tridata Instrument display and MFD would each be interfaced as spurs to a powered and properly terminated SeaTalkng backbone.