Datamarine Depth Instrument/Transducer

[Lancer28]

sailormon6, I have noticed that 99% of the problems on these gauges are not the equipment, but the wires. they were made CHEAP and used steel braids inside which got corroded and nasty within a year or two. On my boat, it was 30 years of water and neglect that gave me black insulation with grey dust inside the wires instead of metal in a lot of cases where it was near the bilge or damp areas.

A fast trip to Radio Shack to buy new connectors and wire saves a lot of hassle. Use the old wire to act like a messenger and pull it through, then trim and attach the connectors.

You might get continuity but there will be tons of resistance and the gauge will not work right wth all of that. Freshen up your wires, it is a fast couple of hours (at most) that will save a lot of stress.

[sailingdog]

That's why I'm going with TackTick for my next instruments upgrade.

Originally Posted by Lancer28

sailormon6, I have noticed that 99% of the problems on these gauges are not the equipment, but the wires. they were made CHEAP and used steel braids inside which got corroded and nasty within a year or two. On my boat, it was 30 years of water and neglect that gave me black insulation with grey dust inside the wires instead of metal in a lot of cases where it was near the bilge or damp areas.

A fast trip to Radio Shack to buy new connectors and wire saves a lot of hassle. Use the old wire to act like a messenger and pull it through, then trim and attach the connectors.

You might get continuity but there will be tons of resistance and the gauge will not work right wth all of that. Freshen up your wires, it is a fast couple of hours (at most) that will save a lot of stress.

[T37Chef]

Originally Posted by foxglove

I have a similar problem. I'm considering buying a chart plotter (although I've never used one) that has a built-in fish finder that I would use for depth (I don't fish either). The transducer can be mounted inside the hull anywhere I want.

The unit is about $400, which is cheaper than replacement for my Datamarine sounder.

Any thoughts on this?

Fox

I have thought the same, and the fish finders typically give you contour of the bottom as well

You will think this is silly, but if I replace the instruments I will have to figure a way to cover the holes left in the bulkhead, ideally a fiberglass job, but I don't wanna do all that

[T37Chef]

Originally Posted by Lancer28

t37, what is the matter with your datamarine gauge? what is it doing? I just rebuilt the depth, knots, distance, AWI and speed on my old boat. Perhaps I can help (and save you tons of money in the end!)

Thanks...

Its reading all over the place, seems to calm down in water less than 10 feet but still goes from 2.5 to 188 feet and everything in between. I have cleaned the transducer bottom to make sure there was not an excess of bottom paint on it.

[Sapperwhite]

Originally Posted by T37Chef

Thanks...

Its reading all over the place, seems to calm down in water less than 10 feet but still goes from 2.5 to 188 feet and everything in between. I have cleaned the transducer bottom to make sure there was not an excess of bottom paint on it.

Funny you say that...... The ONLY time my depth transducer acted up was in the Patapsco. It would bounce between 2.5 and the true depth. It doesn't happen to me anywhere else.

Also, if you go with a chartplotter/ fishfinder combo, shop around. Many of the cos. building them make a variety of transducers for their units, both thru hull and external. You may be able to get a thru hull transducer that fits your current hole. That would make for a good winter project if you haul out for winter. Here is one example: Garmin 500 series has quite a few different bronze thru hull transducers available that are compatible with the unit. Check the accessories tab. https://buy.garmin.com/shop/shop.do?cID=150&pID=8057

I'm sure Raymarine has similar offerings.

[T37Chef]

Thanks...looks promising as does DMI

[Lancer28]

t37, try your gain adjustment behind the gauge and check the wires for resistance and/or corrosion by peeling back some insulator near the transducer.

You could be getting "bounce" when the sonar ping hits the bottom, then refelcts off the surface of the water, then back down, and so forth, without giving a good reading.

Don't peel back the insulation too close to the transducer to the point where you can't solder in good splices of new wire to replace the old crap. Also, squirt a bit of PB or WD-40 on the connections, and softly sand to reveal new metal. Coat them with electrical grease and re-assemble. if you're not too keen on sanding, an eraser can work too, but takes a while and is hard to get in to tight spots.

Also record resistance measurements before and after cleaning. Simply disconnect the terminals on each end, short the far end together, and read through the wire on the other end. You should have a very nominal measurement even over a 50 foot run of coax. You could even compare to new wire to see how far gone the old stuff is.


TRANSDUCER=====>Connection<======Wires to gauge====
..........check ^^^ here......check ^^^ here

on the other end:

Wires to Gauge==========>Connection<======Gauge()
...................check ^^^ here..........check ^^^ here