Transducer selection

[Chuck - Raymarine - Moderator]

Don,

The problem reported would not result from a LightHouse software problem. In a nutshell, 1kW and 2kW 50kHz/200kHz transducers which have been designed for use with Raymarine fishfinding products feature a sense line which presents a 3kOhm resistance to the fishfinding product. Should the Raymarine fishfinding product not detect 3kOhm resistance on the transducer's sense lead, then the Raymarine fishfinding product will assume that the transducer is a 600W transducer and the a/c/e/eS/gS-Series MFD's transducer selection list will display the transducers options listed below:
- P58/P65/P66
- P79
- P319/B117/SS555
- B66V/B66VL
- B744V/B744VL/SS...
- B45
- B60/SS60

However, should the Raymarine fishfinding product detect 3kOhm resistance on the transducer's sense lead, then the MFD's transducer selection list will display the transducer options specified within my initial response. Accordingly, should the MM1-DST-RAYA cable (should feature a 9-pin plug on the end to be connected to the MFD's Transducer socket) not provide the 3kOhm resistance between the transducer's sense lead (pin 5 of the plug to be mated to the MFD's transducer socket) and ground lead (pin 6 of the plug to be mated to the MFD's transducer socket), then the MFD's transducer selection list will display the transducer options specified above and it would be recommended that Airmar be contacted to determine why the Airmar adapter cable is not providing the required 3kOhm resistance for a 1kW transducer. Should 3kOhm resistance be measured between the cable's sense lead ground lead, then it may indicate a problem with the MFD's fishfinder circuitry and it would accordingly be recommended that the MFD be sent to Raymarine’s Product Repair Center to be bench checked / serviced.