Fish Finder troubles

[Simon Everett]

Right folks - not just Nifty, but me too.

 

I have come to the point where I need to fit mine now. BUT the Transducer has come with either 25 or 30 feet of cable!

 

Fitting the display is simple - I have a cunning plan (of Baldrick proportions too )

 

To make a nice, neat, installation I want a shorter cable on the end of the TX - anyone KNOW any reason why I shouldn't cut the cable and then rejoin it shorter?

 

There are things like standing waves in the wire to consider - and what type of wire is inside, is it co-axial, or semi-conductor bimetal? It may not be solderable even.

 

I think there is a short cable option - whic I will see if I can swap mine for one if they do it! Otherwise, I just have to carry a coil of cable.

 

Roll on Spring.

[Yakity - Yak - u.k.]

Hi Simon.

 

Not at all sure of any technical information.

I suppose the manufacturers are the guys to ask.

 

Think most of us using Fishfinders have coils of wire inside the hull.

I know mine is wound up and held with duck tape , dosnt cause any problems.

 

Descision time

[Zzippy]

Hi Simon.

I have my cable coiled round the Noodle joint which my transducer is placed in.It keeps it all neat and tidy.

Zzippy

[Martin Hurst]

I'd be interested to Know if anyone has the Cuda portable (the one with the rechargable base) and whether the suction transducer works ok , especially after witnessing poor Niftys troubles with his Garmin!!!!!!

[Hake]

Martin,

 

I have a Garmin protable fishfinder and the suction cup on that work really well on flat surfaces....unless the surface has been painted with antifoul paint.

 

Don't know if this piece of wisdom is of any help ? (I don't imagine your yak has been antifouled).

 

Mike

[spanner]

Simon,

 

I did the unspeakable and cut mine..... not because I wanted it shortened but because I didn't want to cut a hole big enough for the plug to pass through, just big enough to fit the gland around the cables.

 

Its a plain old cable, 3 or 4 core I can't remember, but and the big BUT, is its shielded with metal foil. A simple solder job will work fine of the cores but you have to make sure you a good job on the shielding. All plugs and connectors will change their resistance with age so a little bit of solder will not make the slightest difference, but a loss of shielding will.

 

Changing the length by cutting the cable shorter will change things quite a bit and I would advise against that as it may screw things up.

 

Mine does have a problem though, which may or may not be related to cutting the cable as I have yet to solve it. I get crosstalk from the NMEA output from the GPS, which I use for the big display and plotting/tracking options on the Matrix fishfinder. This only occurs in deep water, typically greater than 165ft, so its only when the signal from the transuder is small, and all I do is switch off the NMEA output when it happens.

 

It might be due to a shielding problem, but its not helped by stuffing both cables through the same gland, so I might just need to use a second gland and seperate the cables.

 

Or it might just be an inherent limitation with small signals. My fishfinder is supposed to be good for ~900ft but the signal fizzles out around 350ft max, maybe too much loss through the epoxy and hull, or too much resistance from solder, but I really doubt that.

 

Anyway, if I know its deeper than 350ft thats all I need to know anyway

Edited January 23, 2006 by spanner

[Simon Everett]

Thanks all - I will go with the coil answer. I was worried about induced currents with a coil being more of a problem than upseting the "tuned" length of cable (Yeah, right - you can buy extension lengths!).

 

What might be a problem is that because of the standing waves within the wire that there are some problematic lengths - for instance 2m might be fine, but 2.03m not.

 

I have weighed the cable and it is just over 1lb - so I shall just have to have another Shredded Wheat for brekky!

[SpeciMan]

... or go to toilet before launching

[Starvinmarvin]

About time to Simon, as for cutting or not cutting, from what I have been told and what I have read on the subject, don't cut it. Coiling is fine, I used a couple of cable ties to keep it coiled and used a longer cable tie to hold it all neatly around one of the scupper tubes inside the hull.

 

As for the extra pound in weight, loose some of the cash from your wallet and then you'll be alright.

 

SM