Anybody know if there is any restriction on the number of extension cables that can be used to the transducer?
I want to build a towfish to get the transducer out of the wake of the boat and one isn't really long enough, two or three would be better.
I can mould over the plugs to seal the water out so not worried about whether the connections are waterproof or not.
I have a structure scan unit on my Humber Destroyer 5.5, my dads been experimenting with a second transducer on his ROV I think about 20 metres was about its limit unless you move the box closer which is ethernet based! He decided that more than this is impractical because the signals are so sensitive.( The reasons behind this were to complicated for me to renember!!)
If your using it for diving as I am i have found mounting transducer on a pole is ideal but ensure its taken up when the water gets shallow, gets rid of the interference around the outboard. My new setup uses a left and a right transom transducer removing the interfrence around the outboard to a higher degree but not as good as the pole!!
If the ducer works over NMEA 2000, max segment length should work to 100m (resistor to resistor.) For the (more common in smallish boats) micro cabling, it's 200m.
At least, that's the general spec of NMEA 2000, as I read it.
Are you using a Y connector and just mounting the second transducer on a standard bracket on the opposite side of the transom?
How are you connecting the pole when required? just unplugging at the box and plugging the pole transducer in?
I am searching for small targets and want to eliminate both the surface and outboard interference, was going to build a towfish but the pole sounds easier as I have a good solid A frame to put a bracket on and it would be easier to build.