Experience w/Airmar Ultrasonic Sensor UDST800?

[Dockhead]

Originally Posted by SailingHarmonie

We had an Airmar ultrasonic. It was AWESOME. Stable, accurate speed values, minimum sensitivity to fouling, just a delight. For 18 months. Then it died. At the price, I can't justify replacing every 2 years.

If I was running a win-at-all costs racing team , you bet I'd have one. For my cruising boat? I'll pass thank you.

"Win at all costs racing teams", or actually most fairly serious racers, use Signet blue top paddlewheel transducers, not these.


I would try one of these myself, but they don't seem to fit the Airmar housings, and I don't fancy surgery on the bottom.

[bbalan]

Hi All,
Update on our experience. After 4 or so months we started seeing the same problem -- speed data coming and going. Sent a video and photos to Airmar. They are sending me a new transducer. And they also provided this when I asked if they found the problem:



https://assets-7484b3de52.cdn.insite...rt-Sensors.pdf


Doesn't apply to older units that have the problem, but may be of help to some...


Cheers,
Bruce

[FlyingScot]

After reading the stories of failure, I would like to share my experience.

Sailing from Aruba to Cartagena, the first two days were light winds and slow speeds.
Our UDST stopped reporting speeds. Well, actually it became intermittent. Of course my first thought was it was failing just like others have done. It took me a few minutes to gain my senses and go clean the sensor. Sure enough, a quick pull and wipe solved the problem. I didn't even have to insert the plug, just kept my palm over the hole.

It has worked great ever since.

The above attached PDF is helpful. Now I need to go look at my purchase date. It will also make me consider adding a regulated power supply to feed the N2K network. There is a lot of money spent on the items that attach to it.

[wholybee]

Until recently I had the CS4500. As I posted earlier in this thread, the control box failed very quickly, and was replaced, but the process was difficult. I was forced to buy a new one, then my money was refunded several months later after their lab tested it.

More recently, something has failed again. Going through the same test procedure as last time and the control box seems ok. Now it is out of warranty, and eff me if I am going to spend $1000 on another one if I can only expect it to last a few years. I still had my old paddlewheel and simply re-installed it.

It's disappointing because while it worked it worked far better than the paddlewheel does.

[Gheinz]

Hi Flying Scot
I had a UST800 circa 2019 or 2020. Like others, speed would come and go and eventually died altogether. I sent it back to Airmar and 9 months later I have just received a brand new one.

It sounds like yours had worked up until recently and cleaning the bottom of it solved the problem. Do you mind telling me when you purchased yours? I am hoping this one I just got is a new generation and all the old issues are fixed. Wishful thinking?

I'll be installing next month.

Gerry

[FlyingScot]

Originally Posted by Gheinz

Hi Flying Scot
I had a UST800 circa 2019 or 2020. Like others, speed would come and go and eventually died altogether. I sent it back to Airmar and 9 months later I have just received a brand new one.

It sounds like yours had worked up until recently and cleaning the bottom of it solved the problem. Do you mind telling me when you purchased yours? I am hoping this one I just got is a new generation and all the old issues are fixed. Wishful thinking?

I'll be installing next month.

Gerry

I purchased May 2021. The PDF said the issue was on units built February 2022 - June 2023.

Seems your date doesn't correspond with the PDF at all so not sure why it failed. How consistent is your battery voltage.

We have a large (1320AH) LiFePO4 bank that never dips below 13V and charging is capped 29 out of 30 days at 13.8V. One day per month I allow it to go to 14.2V to balance.

[Gheinz]

We’re still on fla batteries and they’re getting changed next month so voltage will not be an issue (I hope) going forward.

Infrequently last year they would seldom dip into the 11+v range but according to Airmar they should operate to 9v. I would like to think this wasn’t the issue in the past. We’ll find out over the next month or two.

Upgrade to LiFePo was on my list this spring but just not going to happen. Investing in new fla which will buy me a few years. In the meantime I have to deal with no major loads on them and voltage drop with SOC. First world problem.

[stgermain45]

Originally Posted by FlyingScot

I purchased May 2021. The PDF said the issue was on units built February 2022 - June 2023.

Seems your date doesn't correspond with the PDF at all so not sure why it failed. How consistent is your battery voltage.

We have a large (1320AH) LiFePO4 bank that never dips below 13V and charging is capped 29 out of 30 days at 13.8V. One day per month I allow it to go to 14.2V to balance.

My problems with the UDST800 don't align with the dates Airmar claims in the bulletin, so I'm not confident at all that they've discovered the "smoking gun" on this issue. My original and first replacement units were March and October 2020 and then they extensively tested my subsequent replacement over the course of 2 months in August and September of 2021. I gave them my data points, observations, videos, etc of the unit malfunctioning while out cruising throughout 2021. Their pinning this issue on a 2022-2023 supply chain shortage and alternate mosfet chip is totally bogus.