B265LH-12P losing bottom on HF

[FishingForFun]

Greetings Forum
I finally installed my transducer, B265LH-12P. My transition to Furuno and the install of TZT16X, Drs4D-NXT, SCX20, NavPilot 300 and the transducer has been fun, challenging and quite the learning experience. I’ve been using everything except the fish finder (internal 1KW chirp) for about a month and now that the transducer is installed it’s time to work thru a few issues. I’ve had 3 opportunities to check the fish finder and it’s pretty nice as long as I’m stopped or idling. Above 1200 RPM and 10 MPH I am getting vertical white lines on my MFD. it gets so bad I lose bottom totally on HF and it hunts for bottom up to 4000 feet. LF still has the white lines but it doesn’t lose bottom even out at 2000 feet. The transducer is flush mounted on the keel pad about 3 feet from the stern on a Jupiter 29. The cable runs forward thru a tube in the bilge with a fuel hose, a positive battery cable for the port motor and a wire for a bilge pump. Initially I ran the cable up thru all the other wires, batteries and electronics like the old B260 was run. Today I pulled it back away from all of that and routed it out of the lower bilge right up to the connection on the MFD. When I took the boat out to test for improvements today it was either minimal or no change. I’m looking for the wisdom of experience to get me thru this.
On a separate note, I have a question about the internal sounder. Does it have BOTTOM DISCRIMINATION and ACCU-FISH?

 

[FishingForFun]

Here are a few photos that may better show what I’m trying to explain.

 

[Deep Blue]

FishingForFun,

The problem that you are experiencing is severe turbulence with your transducer. Turbulence generally impacts the transducer's Low Frequency first, and if its bad enough, it will then impact the transducer's High Frequency next. If you notice the gaps that I have highlighted in the picture that you have provided reflects this.



Fish finder transducers cannot transmit through these "air bubbles", and that is why you are seeing these air gaps on the screen.

You need to find out what is causing all this turbulence. You need to see what is the water flow that is front of the transducer and why is it causing it to be subjected to all kinds of turbulence. Is there a water intake, or a hull strake that is causing this..? You might need to use a fairing block to get the transducer away from the hull into a much cleaner water flow.

A very wise man told me once: "The transducer is the heart and soul of any fish finder. Without one of good quality and proper installation, the fish finder cannot operate to its full potential"

Regarding your next question, Yes the TZT16 does have Bottom Discrimination and ACCU-Fish features, but you must be using a transducer that has this capability like the 526TID-HDD.

- Deep Blue

 

[Johnny Electron]

If the transducer install really looks like that, it is most likely part of the problem. It needs to be flush with the hull and no cavities to have water curl into.

Those gaps are not good as well it might not be flush to the hull.

 

[FishingForFun]

Deep Blue and Johnny thank you. When I took that picture yesterday I saw how the “sealer” that I had put in the previous day to smooth it out was not staying in. I used BoatLife caulk for the full install and I tried to add some in a few places to smooth it but I guess it needs to set up longer than overnight. With your suggestions I’ll start with that and report back. Many thanks to you both.