Airmar B265LH and DFF1UHD False Bottom and other trouble

[Whiplash]

Hi All,

My B265LH paired with DFF1UHD stopped working suddenly during a trip. I performed a factory reset on the DFF1UHD while talking with a very helpful Furuno tech. I also did a master reset on the TZT2. After the reset I was able to read bottom again, but appears I have a false bottom and need to turn up the gain to 80+ and TVG way up to read real bottom.

Sorry for the bad screenshot, that "mark" on the screen is actually bottom without the gain turned up. You can see the false bottom at 3 feet. TIA

 

[Sparky Wire]

Marine growth or any paint on the transducer face?

 

[Johnny Electron]

That doesn't look like a false bottom to me. That looks like you turned on the temp line graph. Maybe check that isn't ON.

 

[Whiplash]

Sparky: the transducer was working well and then stopped while offshore. It lost bottom around 1,000' then never came back and started bugging out with no returns. No new paint or growth...

Johnny: The temp line is the single black line at 7 feet. So unfortunately not that.

I'll try to get some better photos in deeper water. Thank you both for the responses so far.

 

[Deep Blue]

Whiplash,

If you reduce the DFF1-UHD's TX Power does that false echo disappear..?

- Deep Blue

 

[Whiplash]

Just got back from a double overnighter in Hydrographer canyon up in New England, no sonar for 48 hours of fishing but hey not complaining.

The DFF3D with 165T would mark bottom up to 500' or so but not once did it mark anything, and we were 100% over heaps of bait with birds chomping down in front of us. The DFFUHD with B265LH decided to completely stop transmitting whatsoever. I'm going to dive under and check for any growth/damage, but barring that I'm stumped as to what the issue could be. I've reset both units (sounders and TZ2's), the 3d is a 2017 and the UHD a 2019. Spent a while on the phone resetting the sounder units with Furuno techs which appeared to help at first, but once out of the marina I couldn't mark anything, not even a humpback swimming under me.

 

[FishTech]

I would suggest getting with a dealer that has an Airmar TDT1000 transducer tester.
They can test the B265LH and for the 165T they can use the procedure we have posted on our website here:

https://furunousa.com/-/media/sites/furuno/document_library/technical_info/miscellaneous_documents/public_tech_info/b54_transducer_testing_with_airmar_tdt1000.pdf

This would verify if there is a hard failure in one of the transducer's elements or not.

Additionally, can you make sure that the cable connections, and shielding, are connected properly per the manual's instructions?
Are the DFF1UHD and DFF3D connected to your performance ground or bonding system?

 

[Whiplash]

Thanks FishTech. Started calling around. I'll take a look at the connections and bonding as I'm unsure right now. I know that each transducer has its ground attached to a clamp on the actual transducer, is this problematic (I could be completely off on this but see picture below)?

Any chance these transducers take Propylene glycol in the unit? Someone mentioned that a few transducers they looked at needed to be filled up and started working well again..

 

[Whiplash]

This is the B265LH

 

[FishTech]

While not the most ideal connection, it is the way that you will typically find it done. I can be the cause of a noise problem. It is easily tested. Just remove the connection and see if it works better. It is a bit of a double edged sword though. If you have an electrolysis problem, the transducer will be eat up first if it is not connected.

These transducers do not use propylene glycol. Those will have a tank (big or small) that the transducer sits inside of. That was a good thing for them to point out though. It is often missed.

 

[Whiplash]

FishTech, forgive my ignorance but that green wire would be my grounding system preventing electrolysis damage to the transducer itself?
Is there another preferred connection here?

One thing that confuses me is both the transducers are not performing as they should, each respectively hooked up to the DFFUHD and DFF3D. This leads me to think it may be an issue with the connection at the TZ2 or the TZ2 itself?

 

[FishTech]

Yes, that is what the green wire is doing.
Preferred would be to drill and tap a hole in the nut during installation and use a machine screw to hold an appropriately sized ring terminal to the nut.
In this installation, the TZT2 is just displaying the images sent to it by the DFF3D or the DFF1UHD.

 

[Whiplash]

Update: Had an Airmar Diagnostic tool run on both transducers.

On the B265LH the HIGH frequency was completely shot, LOW was to spec. 2000 hours on the unit and it is a 2019.
T165-B54: completely shot and impedance way too high. Unsure on hours but it is a 2017.
I just purchased the same transducers to replace.

I bought the boat in 2023. I'm trying to think of reasons why 2 top of the line transducers both fail so soon. My 1 thought is that the previous owner left them on at his slip frequently given the extremely high hours averaging 400 hours/season which I know for a fact he did not put on the engines.
Does anyone know if constant transmitting, or perhaps shallow transmitting in a slip would cause damage or significantly reduce lifespan? Also, I do not think they were run dry.

 

[Sparky Wire]

Speculation is just that, but you should never run higher power transducer in the air as they need the water for cooling. Elements get hot and crack. There are other reasons transducers fail like water wicking into the housing if someone suburges it from the top and corrosion kills them internally sometimes pushing the material out of the bottom of the housing. Hard to say why they died.

 

[Johnny Electron]

Top of that transducer in the photo looks awful. I would make sure that isn't getting water over transducer on the inside of the hull. The B265LH is one of my favorites. The B164 is my last choice for anything unless nothing else works for the application.

 

[Deep Blue]

Whiplash,

The majority of the CHIRP transducers that I have seen burn up are a result of:
A. Running the transducer at a higher power than it was rated for. 1kW Transducer being run at 2-3kW of power.
B. Leaving the sounder running while the transducer was not completely immersed in water. i.e. loading a boat on a trailer and not shutting down the CHIRP sounder and the transducer has no way to keep itself cool, and thus this causes the elements fracture due to heat.

- Deep Blue