Do transducers wear out?

[yarcraft91]

There are some interesting recent comments that transducers wear out in some way and should be replaced periodically. I'm interested, since I never thought of transducers that way and have treated them as permanent. Obviously, we want the best from our electronics, so this topic seems worth some sharing of thoughts.

I can think of several ways transducers might fail, here are two:
1. Scarring of transducer face.
2. Failure of the electrical connections inside the transducer.

Transducer face scarring
The comments regarding #1, as I intrepret them, are that the surface of the transducer should look like a new car finish- shiny and smooth. It makes some sense, if scars at the transducer/water interface scatter some of the sonar pulse and distort the optimum "cone" shape. I noticed that the last two 200KHz Skimmer transducers I received from Lowrance each had scratches and marring of the transducer face right out of the box, so if the scarring concern is valid, there is one of the reasons I am disappointed with my newest Lowrance sonars- poor QC in their transducer manufacturing process. The defect looks like something that could be fixed with wet sandpaper and rubbing compound. Running through lakes at high speed and impacting abrasive floating objects (for example, weeds or sticks with zebra mussels) and towing with all the road grit and gravel blowing part the transducer would also scar the transducer face over time. Again, polishing the face might be all that's needed to improve performance. For anyone who's done auto body work, this would be a quick and simple maintenance task. Moral of the story- inspect the face of your transducer and shine it up if it is rough. If it's new, send it back and ask for a replacement.

Electronic connections
There was a thread about broken transducer wire insulation and a noisy transducer, presumably due to water intrusion into the cable or transducer. The piezo crystals I've worked with in the lab have all-gold electrical connections, and I expect that's how our sonar transducers are built. Water entering the transducer is not going to hurt those connections, but if it wicks into the right place it could provide a short circuit path between the connections and that would probably degrade performance of that transducer permanently. Moral of the story- inspect your transducer cable periodically and replace the transducer if the cable insulation has cuts.

I'm interested in other thoughts. Meanwhile, I'm going to shine up my transducer...

[gofishwalleye]

I too have been told to wax or shine the bottom of my skimmer transducer. As to wearing out I guess it's possible but bad out of the box seems to be the likely failure. I posted on another thread recently, my 332 would loose bottom contact at any speed above trolling. I replaced the transducer and now maintain bottom contact through all speed ranges. Someone posted that it's not uncommon to go through two or three transducers before a good one is found. All my comments refer to lowrance products.

[blueicecpa]

Very good Summary
#3 Transducer crystal wers out when the unit is on , how many hours is the life going to last. Still rersearching why we might change it annually.

From Lowrance:
Here are some solutions that have helped many of our customers.
Losing Depth When the Boat is Moving
This is likely due to turbulence in the water surrounding the transducer. You may need to move the transducer lower in the water or to another location. The transducer cannot send or receive signals through air bubbles.
Losing Depth in Shallow Water
It can be difficult for a high-powered unit to capture the lightning-fast return in shallow water. Turn off the automatic sensitivity setting and manually reduce the sensitivity until the unit locks onto the bottom.
Losing bottom over weeds
When trolling over weed beds in 20ft of water or less, you may experience vertical bars, loss of the chart picture, or the digital depth. First, do a soft reset of the unit. Click here to find the reset procedure for your unit. Then go to the Full Sonar Chart screen. Press Menu and select Sonar Features. Now turn the Chart Manual Mode to On. This will leave everything in Automatic Mode except the depth. Now go back to the main menu and set the depth range for the depth you are in such as 0-20 feet.
Losing Depth When Another Sonar Unit is On
If two or more sonar units using the same transducer frequency are operating at the same time, one or more of them may lose the depth reading due to interference. It is like two radio stations trying to both broadcast on 97.3FM. In shallow water, if the transducers are far enough apart, you may be able to operate them together. However, the deeper the water, the wider the beams spread out. When they cross each other, the interference occurs.
No Depth Reading at Any Time
Clean the bottom of the transducer. Make sure the beam is shooting down (see picture below). Check your transducer connection to the back of the unit. Check the connector pins for corrosion. Check the cable for frayed or pinched areas.

Phone a Friend
If a friend has the same transducer and power connection on their boat, try your unit on their cables. If your unit works on the other boat, you transducer may need to be replaced.

[blueicecpa]

http://www.furunousa.com/Furuno/Doc/...%20-%20web.pdf

Great Transducer Information
& re crystal

The Essence of a Transducer
The physical device inside a transducer that
creates the sound wave is a piezoceramic disc
called the element. The element, when voltage
is applied, vibrates - it distorts and reforms its
shape in very rapid succession. This vibration occurs
at a specifi c frequency and creates compression
waves, or acoustic energy - sound waves.
These waves travel outward from the element
in a vaguely cone-shaped pattern and encounter
targets along the way.

As this acoustic energy encounters targets such
as fish or bottom structure, some of the beam
will be attenuated (absorbed by the target), some
will be refl ected back at the transducer as an
echo and some will be scattered. As the refl ected
echoes strike the transducer they cause a minuscule
distortion in the shape of the crystal. This
distortion of the crystal creates a small fluctuation

of voltage, which can be detected and

processed by the fish finder. The end result is an

image on your display.

[icontact]

I have had Lowrance sonar for almost 20 years now and 2 of my older units still have the original transducers with them and they work. I have not used them for a few years now, however I picked up a small river boat about a month ago and installed my X-70A again. Although this unit is only about 10-12 years old the transducers reads perfectly the same as when I bought it. I am not sure if it is Lowrance or who, that is trying to imply that transducers only last a year or two, or they don't work because they were left on the boat over winter.......or any other number of lame excuses.
That's BS, when are you guys going to own up to the fact that ever since Navico bought Lowrance and moved production to Mexico that a lot of your units now suck, and suck big time. Please Lowrance no more excuses about antennas, software, screens, transducers.........just fix your **** product!!!!!!!!!!

[blueicecpa]

The Question would be how many hours a year do you have your sonar transducer on. Thea crystal has only so many hours of electricity before it wears out. I am waiting for the answer from Airmar the company that makes them for most companies sonars.


And yes if there are now Quality Control Problems that just compounds the problem.

[mnxd9]

Not only that, I read I believe in the owners manual to keep them clean, the dirt build up can interfere with proper readings.

[blueicecpa]

Yes, transducers wear out, or get weak after a period of time.

[IMG]aoladp://MA20305370-0001/image001.gif[/IMG]
Linda Colt
Customer Walk in Service Department
12000 East Skelly Drive
Tulsa Oklahoma 74128
1-800-324-1356 ext 8747
Direct Line 918-438-8747
Linda.colt@navico.com

[ziemann]

This sounds like a great excuse to sell tranducers- whether you need them or not.... How pathetic....

[yarcraft91]

I've seen clear evidence that nominally identical transducers do not perform the same. I'm still looking for evidence that they wear out and I haven't found any. If anything, I've found the opposite.

Here a quote from the Vexilar web site FAQs page:
"Q: Will my old transducer from my FL-8 or FL-18 work with my FL-12 or FL-20?

A: Yes, all transducers are fully interchangeable between the FL-8s, FL-18, FL-12 and FL-20's."
That was an excellent opportunity for Vexilar to say "but you should buy a new transducer because old ones wear out. " They didn't say that. Another Vexilar FAQ:
"Q: How long can I expect my FL-8 to last?

A: All of the FL series flashers are incredibly durable. The case, switches, and electronics will last for many years. The motor and display brush assembly, however, have a limited life time. You can expect to replace these two items every 5 to 7 years, if you use the unit a lot."
Same opportunity and no mention of transducers wearing out. A final quote directly on point:
"Q: Do transducers go bad?

A: On average, transducers fail more often than the sonar units they are connected to. The biggest "killer" of transducers is impact damage. This is usually evident by severe scratches or dents in the plastic housing." I don't think they are talking about minor scuffs.

My buddy ran this test on Lake Michigan. Two 200 KHz skimmer transducers mounted on the same boat, one that came new with a Lowrance 330 (and near zero hours use), the other came new with a Lowrance 334C (used >400 hours). With the same 334C attached to each transducer, the 330's transducer could not mark bottom beyond 200'. The 334C's transducer marked bottom deeper than 400'. His conclusion- the transducer that came with the 330 was not as good as the one that came with the 334C and hours of use had nothing to do with it.

The transducers are synthetic crystals of barium titanate, lead zirconate titanate or similar ceramic, piezoelectric materials that are shaped to resonate at a specific frequency. The width determines the "cone angle", while the height determines the resonant frequency. That frequency must match the frequency transmitted by the sonar unit or there will be much less pulse strength transmitted into the water. I suppose the crystals could develop cracks or other flaws from stress (like collisions). I'd expect that would cause the transducer to stop working altogether, not simply return a weaker signal, because it would change the shape of the crystal and therefore the resonant frequency. The difference my friend saw could simply be due to one crystal matching the 334C's 200 KHz frequency better than the other transducer did, which could be a matter of QC in the transducer manufacturing process.

So, where's the evidence that transducers wear out? I'm still looking.