Interference on TZ Touch 3 Chirp

[ELGATODOS]

We have a TZ touch 3 based system on the boat. Chirp transducer.
We have interference that increases on the screen as the RPM's increase.
This is caused by only the port motor, the starboard one has no effect.
I had the alternators rebuild last week, as they needed it, but that did not reduce or effect the problem.
We use a common ground in the bridge for all electronics up there.
Any advice would be appreciated.
First picture is at the dock, with boat in neutral revving to 2000 rpm
Other picture is offshore at similar rpm

 

[Quitsa]

Are you able to verify that the shield wire on your transducer cable is properly connected? Does the interference filter on the sounder setup have any effect?

 

[ELGATODOS]

Are you able to verify that the shield wire on your transducer cable is properly connected? Does the interference filter on the sounder setup have any effect?

Thanks for the reply. I will check both today and reply back. Thanks

 

[ELGATODOS]

Are you able to verify that the shield wire on your transducer cable is properly connected? Does the interference filter on the sounder setup have any effect?

There is no "shield wire" on the transducer cable. Just one black cable that connected directly to the TZ touch 3 19"
The Interference filter is set on "high" and seems to have no effect.

 

[gtstang462002]

Where is the transducer located at relative to the motors?

 

[ELGATODOS]

Where is the transducer located at relative to the motors?

It is toward the very front of the motor. It's through hull so it can't be moved. On the last boat, 1984 36' Hatteras we did not have the issue and used the same hardware. Current boat is a 1999 43' Riviera with a pair of Cat 3126

 

[gtstang462002]

I have a 1997 Sea Ray 370 Express with the same motors with identical symptoms as you are describing. My sounder on this boat is a B265LH. I believe that those motors have a frequency that these CHIRP sounders do not like. I moved my through hull back as far as I could after the initial installation was almost unusable on plane. This seemed to help it some. Due to the configuration of this boat I had extremely limited mounting options and the lifting strakes don't help anything with air bubbles. I have a DST810 on this boat to get me depth at speed and just use my downscan sounder for trolling purposes while fishing. I have an old 744V that seems to be unaffected by engine noise.

 

[ELGATODOS]

I have a 1997 Sea Ray 370 Express with the same motors with identical symptoms as you are describing. My sounder on this boat is a B265LH. I believe that those motors have a frequency that these CHIRP sounders do not like. I moved my through hull back as far as I could after the initial installation was almost unusable on plane. This seemed to help it some. Due to the configuration of this boat I had extremely limited mounting options and the lifting strakes don't help anything with air bubbles. I have a DST810 on this boat to get me depth at speed and just use my downscan sounder for trolling purposes while fishing. I have an old 744V that seems to be unaffected by engine noise.

We have the 275 BLHW
There is a also a 1kw Garmin transducer that was on the boat when we bought it, we hooked that up to a Furuno FCV-295 for a bit and there was no interference. Our sounder is on LOW, when we switch it HIGH it becomes totally unusable.

Thanks for the reply

 

[gtstang462002]

I am sure @Deep Blue will chime in here soon with some possible solutions.

 

[ELGATODOS]

The transducer cable was running along side the power, ground and signal wires for my Glendinning controls, I separated them, we will see if that makes any difference on our trip tomorrow.

 

[Quitsa]

There is no "shield wire" on the transducer cable. Just one black cable that connected directly to the TZ touch 3 19"
The Interference filter is set on "high" and seems to have no effect.

There s a shield wire, you just can't see it because it is inside the cable sheathing. Since you seem to have a factory installed connector on the transducer cable, it is unlikely that the shield wire is not connected properly, however.

Are you able to follow the routing of the transducer cabe? Does it go near other wires or close by the port motor? (I was writing this when you posted the above about separating the wires.)

I am curious when you say there is a "common ground" for all the electronics on the bridge. Do you mean that you take the negative wire from all the electronics to a single terminal block? Or do you have an actual "earth" ground that is connected to the different devices? If you look on the back of your TZT 3 display, you will see a stud with a wing nut. That is the "earth" ground.

If you have a suitable length of wire, I would try completely isolating your TZT 3 from the rest of your electrical system by hooking it up directly to a battery that is not connected to anything else on the boat.

 

[ELGATODOS]

There s a shield wire, you just can't see it because it is inside the cable sheathing. Since you seem to have a factory installed connector on the transducer cable, it is unlikely that the shield wire is not connected properly, however.

Are you able to follow the routing of the transducer cabe? Does it go near other wires or close by the port motor? (I was writing this when you posted the above about separating the wires.)

I am curious when you say there is a "common ground" for all the electronics on the bridge. Do you mean that you take the negative wire from all the electronics to a single terminal block? Or do you have an actual "earth" ground that is connected to the different devices? If you look on the back of your TZT 3 display, you will see a stud with a wing nut. That is the "earth" ground.

If you have a suitable length of wire, I would try completely isolating your TZT 3 from the rest of your electrical system by hooking it up directly to a battery that is not connected to anything else on the boat.

I have a ground wire in the bridge that runs to panel in the salon. All my bridge 12v runs to that point for the ground, including the TZ touch 3's earth ground.
I'm sure a solution would be installing it's own battery and charger in the bridge, which we may do, but not until the fall. Was hoping to solve the issue another way first.

Thanks, Bryan

 

[Quitsa]

I have a ground wire in the bridge that runs to panel in the salon. All my bridge 12v runs to that point for the ground, including the TZ touch 3's earth ground.
I'm sure a solution would be installing it's own battery and charger in the bridge, which we may do, but not until the fall. Was hoping to solve the issue another way first.

Thanks, Bryan

I wouldn't be so sure that a separate power supply would solve the problem if the noise is being picked up by the transducer or its cable. It's worth trying temporarily to isolate power to the TZT 3 as a diagnostic step, however, just to remove one possible source of interference.

 

[Deep Blue]

Elgatodos,

All the recommendations that Quitsa has suggested to you are the same recommendations that I would make.

Several years ago I did have a boat that was experiencing the same issues that you have, (and was especially bad in deeper water...) onboard a custom boat using a Volvo Penta Diesel Inboard. During the higher RPMS, the engine was producing noise on boat's 12 volt electronics supply.

We isolated the power going to the TZT3 using a separate power conditioner and then found a good clean earth ground to connect the TZT3's earth grounding stud. By doing this, we managed to clean up that electrical interference.

We never were able to figure out exactly why the Volvo Penta was generating so much noise on the 12 volt electronic supply, (there were other marine electronics units onboard that were also being effected as well. and adding noise suppression on the alternator did not help...) but we did determine that the engine was generating the noise and we were able to stop it using a separate power conditioner and a good clean earth ground.

Welcome to the wonderful world of marine electronics: "Where in theory, theory and practice are the same. But in practice, they are not"...

- Deep Blue