FASTFJR

On Sunday I had my boat in the driveway. I was goofing around with my Garmin 2010C, when my neighbor said "I hope thats not hooked up to a transducer". Yes it was, a shoot thru. He said if you have power to the transducer when its not in water you can damage it. This was the 1st time I ever heard this. True????

Tightline Rod's

It's not the greatest thing for them but your ok ...

John

Mumblerone

IMO, you don't have damage! Have done it many times.

FASTFJR

Thanks, that what I thought.

swamppro

You're ok. If you started marking alot of fish I might visit your driveway though!

dowop

I'm not sure I fully understand how this can be a problem - it just does not add up (from an engineering point of view). The transducer sends out a ping and there is no response - this will not damage the transducer. This happens all the time for those people that lose bottom at high-speed with a transom mount transducer or without good water below their transducer.

FASTFJR

Just passing along what my neighbor had told me. I did not understand it either. This guy was in the Navy for 25 years thats why I thought he might have somthing.

KJS

I just installed a Raymarine this winter and it actually says to turn it on to test it by seeing if the temp reads. Dowop makes a good point too. Sometimes we worry too much about our boat stuff (I am very guilty of this).

E Fitzgerald

I can think of a couple of reasons why you may not want to run a "dry" transducer for more than a few seconds. (Though the in-hull transducers such as those you mentioned are probably less affected.)

1.) Heat - transducers only convert about half the electrical power into acoustic energy. The rest of the power is turned into heat energy. Most transducers use a variety of adhesives inside (PSA, urethanes, etc.) which can soften when warmed enough. Also the baffle materials can liberate air (if they were not properly degassed during production) which can cause components to delaminate.

2.) Impedance - transducers are make to be operated when the acoustic face is "loaded" - meaning that you need to have pressure against the face of the transducer. Without this loading some characteristics of the transducer change - if you measure the impedance of the transducer it will typically be lower when it is out of the water. This does not damage the transducer but I can see potential damage to the echosounder output stage if it goes unchecked. E Fitz.

bravajo

I should preface this by saying that I am 100% anal about these kind of things but my 600L Installation manual explicitly recommends connecting the ducer to the head unit and powering it on. Then verifying the "rough" air temperature and the speed by spinning the paddle wheel before going through an installation. I would not recommend leaving it on for a week like that but I doubt the manufacturer would include that in the instructions without a huge warning that says "DO NOT LEAVE TRANSDUCER ON AND OUT OF THE WATER FOR MORE THAN 10 SECONDS OR ELSE PERMANENT DAMAGE WILL BE DONE" especially on a unit that is guaranteed to be brand new and under warranty.

If my microwave oven manual says not to bake kids or pets to dry them off after a rainstorm I would expect Furuno to make mention of the damage running out of water could do

J.

PRAFT

If running them out of the water harmed them I would be replacing them quite often as the sounder fails to get turned off for the ride home on the trailer. Maybe I should be checking the memory card for good spots when I get home. Think I passed over a couple cats and a armadillo or two.

Depending on the power of the sounded I could buy into the heating thing.

Don

warthog5

Your neighbor was telling you what he knew from the Navy. I was Sonar Tec on Subs. This was also told to us.
The system's aboard Navy ships are a lot more powerfull than what we use on our fishing boats.

TTaxi

Just thought you might be interested in a semi-recent post by "Eyeball" to this forum that I had filed away- it makes sense to me:
Eyeball
Posted 4/6/2005 10:05 PM (#583861 - in reply to #579994)
Subject: RE: Airmar M260 Making Noise?

Click for more info...

Posts: 178

Registered:
2004-12-22

If the transducer is properly assembled you will not hear a noise. Every part of a transducer should be assembled ridged. The idea is to have the energy exit the acoustic window on the bottom of the transducer as a sound wave. Clicking means something else inside is moving and sound is exiting in a direction other than the acoustic window. And if something else inside is moving energy is being spend on making whatever is moving move. As far as the frequency goes, nothing about the typical recreational transducer’s operating frequency ever gets close to what a human (or dog) can hear.

A nominal clicking noise, one you would need to be near the transducer to hear can be made by a loose assembly as Whalerboy mentions if an element was not bonded properly during manufacturing or becomes un-bonded. A loud clicking noise as you have mentioned is indicative of a cracked ceramic piece that has broken off and getting knocked around or by arcing thru a crack in the ceramic. With any of the above your transducer is damaged but may still function but obviously at a reduced level.

How does the ceramic around an element get cracked or broken? Easy…take you boat out of the water and turn on the sonar and let the transducer pound away. A transducer requires resistance on the acoustic window to function properly and to prevent the un-bonding and cracking problems mentioned above. When I talked to Airmar’s engineering about this, they said their transducers are good for up to 60-seconds out of the water, but they recommend a 30-second limit, if at all. Simrad says never operate their transducers out of the water.

Now, (hopefully) this is the part where you tell us your transducer is in-hull mounted and always has resistance on the acoustic window and has never been operated in the air…or (not hopefully) how long you left the sonar pounding away while your boat was on the lift before you noticed the noise.

dowop

So what this is telling me is that the plastic surrounding the transducer element is not providing resistance. Well it is.... it might not be what Airmar is talking about, but it certainly is providing a resistance equal to or greater then the fiberglass that it shoots through.

FASTFJR

I'll let you know in 2 weeks when I get in back in the water. Weather sounds like crap for this weekend.
Thanks for all the info