Range Limit with AIRMAR tranducers - help!

[JESSEDIVER49]

I have a 42 GB that previous owner installed 2 Airmar transducers, one is "depth/temp" and other is "speed/temp".
I do not get any temp readings because I think, signal interference from 2 transducers. Transducer readouts are on Simrad IS-20s.
But that's not my concern. My concern is my DEPTH readings are limited to about 100 feet yet the transducer spec says it's good for 330 ft. I use the boat partially for scuba diving and need depth indication beyond 100 feet.
With current knowledge after talking to tech folks at Airmar is one of two possibilities: 1) need to clean the transducer, or 2) faulty transducer that needs replacement.
Can anyone shed more light on this problem? Also, I am on a learning curve and have yet to attempt an in-water removal of the transducer by using the plug to insert after yanking out the transducer. Can I get some practical experience guidance on the wisdom of doing this? I know the transducers are in there tight and maybe stuck because I already tried pulling pretty hard to get them out and neither one budged.

 

[hmason]

When you pull out a transducer you need to be ready to push the plug in really fast. If the transducer is, for example, 3 feet below the waterline a column of water 3 feet tall will leap out of the through hull fitting. It can be a bit frightening but the plug will stop the flow. Just react quickly and deliberately and don't panic. The first time I tried this I was a complete newbie and damn near fainted when that column of water erupted.

 

[twistedtree]

I don't think the transducers will interfere with each other on temp. Depth maybe, but not temp. What models are they? And are they NMSE 2000 or 0183 or something else.

 

[psneeld]

I don't think the transducers will interfere with each other on temp. Depth maybe, but not temp. What models are they? And are they NMSE 2000 or 0183 or something else.

+1

 

[JESSEDIVER49]

Range Limit with AIRMAR

The Depth & Temp is PN 44-151-1-01
The Speed and Temp is PN 44-157-1-01

both are NMEA 2000.

 

[FlyWright]

Does the operation return to normal with just one system activated at a time?

What happens to one system when the other is turned off and vice versa?

 

[twistedtree]

The operating frequency will be labeled on each unit. They should be different to prevent interference. If they are the same frequency, then I like the idea of unplugging one to see if the other performs better.

If this is the transducer I think it is (DT800 and ST800), they seem to have a pretty high failure rate. I lost temp on mine after less than 3 years service. And I know others who have had failures too. So your lost temp is likely a bad sender.

As for depth, I have always found mine good to around 500-600 ft, but then it loses it. They just don't have the power to get deeper. 100' sounds like a problem, and fouling of the transducer face would be a first place to check. There is special anti fouling paint that you can use on them. Do not use boat bottom paint.

When swapping, be sure to have the plug right in hand and pre-greased. I found in removing the old one that you need to work it, ideally twisting is back and forth to get it out. BTW I chickened out and changed mine when I was hauled. Glad I did because it turned out I Had the "long" version that goes through a fairing block, and the replacement I bought was a shortie.

 

[Maerin]

Your potential for things going badly or not as planned with swapping a transducer is pretty high. Unless you know that you've got the exact replacement, I'd be reluctant to try wet-swapping. If someone else installed the transducer you're removing with 5200, it could be really interesting.

Why not install a replacement that shoots thru the hull? You can run the cable and keep it as a redundant backup if you eventually replace the thru hull. I have one that I can simply switch the cable at the network sounder, so it's relatively easy to get back in service.

 

[MYTraveler]

My dinghy's cheap fishfinder can track the bottom well over 300'. My Furuno (DFF3, with 3kw 50khz transducer) easily tracks, with good bottom definition, at over a mile deep. Something is wrong with your system.

 

[danderer]

If this is the transducer I think it is (DT800 and ST800), they seem to have a pretty high failure rate.

Similar experience here.

When swapping, be sure to have the plug right in hand and pre-greased.

Good advice. Somewhere the PO lost the plug for mine. I did the swap without a plug by inverting a small bucket over the fountain. Not pretty but it did kind of stem the flow as long as I kept significant weight on it.

 

[meridian]

It could be the device that is driving the transducer that is failing. Transducer is a pretty simple device.

 

[kev_rm]

My airmar shoot through hull is good to 900+fsw

 

[Xsbank]

Make sure there isn't a happy family of barnacles residing on it - there shouldn't be any paint on it, the little buggers like that.

 

[FlyWright]

My airmar shoot through hull is good to 900+fsw

kev, will that shoot-thru-hull transducer penetrate 2 inch solid FRP?