It’s the DI, I guess the question was 2 part. I’d like to get something that will work best for the price and the space, or lack there of. There are 2 cables.
The smallest model that will work with the MDI transducer is the Helix 7 CHIRP MEGA DI GPS G3N. Then the next sizes in order are:
Helix 8 CHIRP MEGA DI GPS G3N and G4N
Helix 9 CHIRP MEGA DI+ GPS G3N or G4N
Helix 10 CHIRP MEGA DI+ GPS G3N or G4N
Helix 12 CHIRP MEGA DI+ GPS G3N or G4N
Helix 15 CHIRP MEGA DI+ GPS G4N
All of them are Ethernet capable (that N thing)=Networkable
If future plans include the MEGA 360 or MEGA LIVE, then it must be a DI+ unit.
The 8-12 G3N's are discontinued and replaced by the current G4N.
There are some G2N's that are compatible but they were discontinued in 2018.
Current units are listed on the Humminbird website with their MSRP.
The iPilot LINK (Ethernet extension cable) is 30' long. To connect that directly to a Helix takes the AS EC QDE Ethernet Adapter.
The MDI transducer has a 14-pin plug for direct connection to a SOLIX. To connect it to a Helix requires a 14-pin to 7-pin adapter listed on the Minnkota website compatibility list--the Helix 7 is different than the larger models----
https://www.minnkotamotors.com/support/compatibility/built-In-MEGA-imaging