A128 & Chirp

[Natch]

In an earlier thread, I requested and received immediate assistance, concerning water temp readings, with just an in hull transducer and the CP 200 module. As I learn more, using my two Raymarine MFDs (A127 & A128) following the transition from Lowrance to Raymarine, I am appreciative of having someplace to go for answers. Accessing menus to make adjustments and setting changes can be a bit challenging, when you have become so accustomed to procedures of another brand for the last dozen years.

I want to get everything I can out of these units, so I figured this was the best place to pick the brains of Raymarine experts. With that, I have a couple of more questions.
I'm not sure which transducer is epoxied in the bilge, which is connected to the A128. However, like the Gen 3 Lowrance, Touch units, the Raymarine A128, has Chirp circuitry built into the unit and should work with a standard 200kHz transducer.
Am I wrong to assume that, because I can't find a chirp selection menu?

Also, this boat was equipped with twin A128s, mounted side by side at the console and a single A127 at the bow. I had no need for the dual set up at the console, so the seller flush mounted a 128 in the dash. So, currently, there are two transducers being read by the A128. The presumed 200kHz in the bilge and the Side Vision transducer feeding info to the CP 200 module behind the steering wheel. I'm assuming that I need to add a CP100 transducer to the back bone to able to use down vision. Is this correct?

The A127 at the bow has a CP 100 transducer mounted to the trolling motor and it provides clear 2D sonar/down vision and water temp, so the fishing end of the boat is fine. Both units read my Navionics chip, which is installed in the 128 as I have both units linked

Thanks in advance

[Chuck - Raymarine - Moderator]

Q1. However, like the Gen 3 Lowrance, Touch units, the Raymarine A128, has Chirp circuitry built into the unit and should work with a standard 200kHz transducer.
Am I wrong to assume that, because I can't find a chirp selection menu?
A1. This statement is incorrect. Please click here to view a FAQ addressing the frequency ranges employed by CHIRP/DownVision transducers which have been designed for use with the ax8 MFDs, eSx8 MFDs, and CP100 CHIRP/DownVision Fishfinder Sounder module. However, a 50/200kHz transducer may be mated to an a127 MFD. A transducer selection feature is provided with an ax8 MFD has been interfaced fishfinding devices (ex. ax7/cx7/e7D/ex7/eSx7 MFDs, CP370, CP470, CP570) which support being used with fishfinder transducer options which have significantly different performance characteristics. In contrast, the ax8 MFDs, eSx8 MFDs, and CP100 CHIRP/DownVision Fishfinder Sounder module are essentially compatible with two types of transducers. Raymarine offers compatible transducers featuring both DownVision transducer elements and a CHIRP (conical) transducer element. Raymarine also offers compatible transducers having only a CHIRP (conical) transducer element. The CHIRP (conical) transducer element found within both of these types ax8 MFDs, eSx8 MFDs, and CP100 CHIRP/DownVision Fishfinder Sounder module compatible transducers is identical and hence no transducer selection option is needed. The ax8 MFDs, eSx8 MFDs, and CP100 CHIRP/DownVision Fishfinder Sounder module automatically sense whether the interfaced transducer has been manufactured with DownVision sonar elements and if not, will not present an option to display DownVision sonar imaging.

Q2. I'm assuming that I need to add a CP100 transducer to the back bone to able to use down vision. Is this correct?
A2. Should a transducer not presently be interfaced to the TRANSDUCER socket of one of the ax8 MFDs, then interfacing a CP100 compatible transducer to the TRANSDUCER socket of one of the ax8 MFDs would add DownVision fishfinder sonar imaging to the system.