Installing a fishfinder

[dan9487]

Evening all /forums/images/graemlins/confused.gif
I'm installing a fishfinder (Garmin 140) and I'm unsure of what to do with the cable, I'd like to do a permanent job of fitting it by running the cable through the transom, along under the floor and out through the dash. Only problem is that the cable is moulded to the transducer at one end and has a 20mm ish plug moulded on the other. The first thing that comes to mind is to cut the cable, feed it through a small gland and re-join it but I'd rather not do this as it will void my warranty and I havent even used it yet!

Has anyone else had this same problem or know of some cunning ways around it or is it going to be out with the soldering iron?

 

[BrendanS]

Most fishfinder manufacturers, and this includes Garmin, specifically say not to cut the cable.
Lots of sites say this is because the cable is calibrated to the transducer and unit, and shortening it, can affect the readings.

 

[dan9487]

Ah didn't think of that, just as well I didn't go with my instincts and cut it then.

Any suggestions for routing it/taking it through the transom?

 

[BrendanS]

I'll leave that to others who are somewhat more practically minded than me! /forums/images/graemlins/smile.gif

 

[alan_d]

Despite the warnings from the manufacturer I have cut and rejoined (without shortening) the cable to my fishfinder transducer and it appears to work just as well. (Garmin 90) The reason given in the manual for not cutting the cable is "because it voids the warranty".

 

[damo]

Any particular reason for running it through the transom?

Mine is stuck down to the inside of the hull.

 

[mainmarine]

you can get larger glands that have a hole for the cable and a slot to let you fit the rubber seal without removing the plug, you then drill a 22mm hole to pass the cable through and fit the gland over the hole.
They are made by Index marine and others, if you cant find them let me know and I will send you a link.

 

[gjgm]

you obviously run it thru the transom well above the waterline, so the size of the drilled hole doesnt matter much.
Once you are "inside" the boat, it should be pretty straight forward?
If you have the choice of in-hull mounting or transom mounting, I found its more reliable inside. Depends on the speed of the boat, maybe, but wash and prop wash seemed to make a transom mounted one a bit of a pain.
Or maybe I was useless at fitting that one /forums/images/graemlins/grin.gif

 

[colingr]

With gjgm on this. Dun the cable up the transom to well above the waterline. Pass through a hols with a suitable grommet. I've got a nice chrome cover that I cannot describe over where the cable enters the boat to make it look tidy.

 

[omega2]

Got to agree with DAMO, stick it to the inside of the hull, I have three working in this manner all give good return signals. Look for a solid bit of hull i.e. no sandwiching by putting transducer in plastic bag with water, and plonk it around the inside of the hull, at least halfway along the length, and clear of any known extrusions that may cause turbulance. First check return by dipping over the side of the boat, note the quality, then aim for same through the hull.

 

[dan9487]

Only because it's a transom mount transducer not a through hull, thinking about it I might have been better off getting a through hull.

 

[blackbeard]

Don't know if it's the same as mine, but mine seemed from the instructions to be designed for transom mounting, reading small print suggested it could be mounted inside, so I did and it works well.
You can always set it up temporarily and see if it works.

 

[JKay]

Garmin 140 transom mount transducer will work in the bilge thru' the hull(single skin grp) find an ideal spot with the transducer in a plastic bag full of water and then mount with a big blob of decent quality silicone,press transducer with small sideway motion to reduce the risk of air bubbles cut excess off a couple of days later /forums/images/graemlins/cool.gif

 

[damo]

[ QUOTE ]
Only because it's a transom mount transducer not a through hull

[/ QUOTE ]

That's what is usually supplied with a fishfinder, so most of us stick it down inside the hull. My transom is about 2' above the water anyway /forums/images/graemlins/smile.gif They seem to be designed for dories, small sports fishers etc, not yachts, but they work perfectly well "indoors". Lot's of threads on the subject if you search the forum.

 

[dan9487]

Ah handy
I wasn't aware that they would also work through the hull, that sounds like it is definately worth trying first.

Thanks for everyones suggestions!