Transducer - 275 vs. 175 for TZT3

[Quinn]

I am about to purchase a TZT3 12 and think I have my transducer choices down to a B175HW (tilted element flush mount 12 degree tilt) vs. B275LHW (fairing block). Putting aside the deep performance of the “275” would I see any difference in the performance of the 275 over the 175 in water shallower than 300’? Is it worth it to have it hanging below my hull? Boat is a 33’, 17knot sportfisher. Fishing is halibut and seabass in 80’ to tuna in open water. Also, what connector do I need to connect to a TZT3?

Thanks

 

[Quitsa]

The internal high frequency element of a B275LHW is identical to B175HW and thus should have exactly the same performance. So the issue then becomes whether the transducer will see the cleanest water flow installed in a fairing block or in the tilted element flush configuration. The argument for the fairing block is that it gets the transducer face away from the boundary layer of water flowing over the hull. However, the fairing block itself can create issues if the installation is not perfect. With a relatively slow 17 kt cruise, my feeling is that the advantages of the flush B175HW outweigh the possibility of a very minor performance difference. Just be sure to choose a location that puts the transducer as deep as possible and close to the keel but without any obstructions forward of it such as strakes or through hull fittings.

I have a B175H and B175L and the B175H reads bottom very well to over 500 feet. The B175HW has less depth capability because of the bean width but a friend who has one has no problems at 300 feet.

You will need a Furuno 12 pin connector for the transducer port on the TZT 3.

 

[Quinn]

Appreciate the detailed response, exactly what I was looking for. Thanks.

 

[buefin039]

I have found placement has to be very well thought out when using tiled elements. Make sure there is no obstructions ahead of the transducer. Even if it is a lifting or spray rail that stops we’ll ahead of the transducer. It does not matter how far ahead something is.

Quality marine electronics “QME” developed a fairing spacer for tilted element transducers that people have had great success with. It has helped many people with a boundary layer issue. I would recommend using one when installing. Some installers won’t put one in without the QME fairing spacer.

Worth checking out and researching it.

Just to be clear, a B275LHW has a low elements and a high wide element. A B175HW has no low. You would have to install a second B175L in order to have both frequencies. The B285HW is the single frequency fairing block version.

 

[allrelative]

I have the B175HW and ground fish up to 400 and tuna fish. Able to see and find bait. I have some great screen shots- its amazing. Like all units, takes time to dial in it.

 

[OFFLINE]

I have found placement has to be very well thought out when using tiled elements. Make sure there is no obstructions ahead of the transducer. Even if it is a lifting or spray rail that stops we’ll ahead of the transducer. It does not matter how far ahead something is.

Quality marine electronics “QME” developed a fairing spacer for tilted element transducers that people have had great success with. It has helped many people with a boundary layer issue. I would recommend using one when installing. Some installers won’t put one in without the QME fairing spacer.

Worth checking out and researching it.

Just to be clear, a B275LHW has a low elements and a high wide element. A B175HW has no low. You would have to install a second B175L in order to have both frequencies. The B285HW is the single frequency fairing block version.

Could you describe the role of the spacer? The drawing in the QME manual seems to show the spacer is a barrel that fits inside the hull -- I'm not seeing how that would improve the transducer's performance.

 

[Titanic II]

The spacer is to accommodate for varying hull thicknesses.

 

[buefin039]

The QME product is the isolation bushing outside the hull. It helps push the transducer face past the boundary layer and has solved poor performance problems for many people. The interior spacer or barrel spacer you have pointed out comes with the transducer from Airmar or whoever the transducer is branded with. It was not the product I was referring to.

A side note on the the barrel spacer: Airmar has found the the hollow area inside their spacer can provide noise to the transducer when close to a vibration source. It is now recommended to fill the hollow voids in the spacers with caulk as it eliminates the noise from showing up on your sounder screen. It does not have to be a caulk with adhesive properties like 4200 etc.