Cutting transducer cables

[gilesfordcrush]

Hello all,

Is it OK to cut and then re-solder back together the cables from a transducer, that run to the instrument? I have the Raymarine i50 and i60 depth, wind and log instruments. I'd like to be able to cut the transducer cables for two reasons. Firstly, it will make running them from the helm into the boat much easier as I have to thread them down a long and tortuous route, and the various connections on the cables make them bulkier than just the wire on its own. Secondly, I am not going to fit the through hull transducers until April, but I want to put my helm back together. Therefore, if I can run the cables now, and re-solder the wires later it makes life much easier. Otherwise I have to take it all apart again in a few months.

The re-soldered connections would be in a clean, dry, and safe area behind the nav station. I'm confident in my soldering skills too.

All thoughts appreciated.

Giles

 

[PCUK]

Almost certainly no. Adjusting the length of a transducer cable generally makes it read wrongly. Usual method is to wind the cable up and stow it somewhere.

 

[Yngmar]

The i50 depth transducer has 3mm spade connectors, so should fit through just about anything (with a bit of electrical tape to protect it and keep it from snagging). If not, the installation manual you should've referred to tells you that you can cut off the spade terminals and then crimp on new ones and even exactly how to do so. That should enable you to get it through anywhere. It also implies that a few centimeters off the length of the cable don't matter - although don't shorten the cable by several meters unless you're sure about the signaling used. The wires in the manual are labeled "piezoelectric+/-", which indicates that they carry raw, unprocessed signals, so try to keep any change in length and/or resistance to a minimum - however, the difference between a mid-point joint and re-crimped spade connectors is minimal - but since "clean, dry, safe" spots on boats are of a very temporary nature, you'll best protect the joint sufficiently if you absolutely have to make one.

 

[CLB]

I have cut and rejoined wires on an st60 transducer with no problems. I didn't change the length of the wire though, so don't know if what PCUK says it true or not.

 

[Minchsailor]

Generally speaking it is OK to cut and shorten the log cables - the signal is just a pulse stream (assuming paddle stream log).

Different matter with the depth transducer; the cable can be part of the resonant circuit - its inductance and capacitance are important. Shortening it will change these, leading to degradation of performance.

 

[gilesfordcrush]

I spoke to Raymarine technical support - perhaps I should have done that first, but at least this way knowledge is shared, which I suppose if the point of a forum.

The chappie at Raymarine says it is fine to cut and solder the transducer cables, as long as I make a decent job of the soldering. I didn't actually specifically ask about shortening, as I have no intention of doing that. It will be easy to coil the spare cable somewhere.

Thanks for all the help.

Giles

 

[[70521]]

All thoughts appreciated.

EDIT: You have done what I suggested.