Onwa NBM40-50/200 (3 pin)

Dual Frequency 50 and 200 kHz Plastic thru-hull transducer 3 pin connector

• 600 Watt
• 50/200kHZ
• Thru-hull fitting
• 8 metres cable

Intended for thru-hull fitting but can be installed in-hull in most GRP hulls. Exception to this is if the hull construction is sandwich type or in a very early GRP hull that is incredibly thick.  Installation method can be as simple as sticking the transducer to the floor of the hull with a blob of silicon (NOT RECOMMENDED) or more correctly by installing the transducer inside a tube or container fixed to the hull floor and filled with a suitable liquid medium. The idea being to have nothing between the transducer head and the hull apart from a liquid that will allow the passage of the ultrasonic signal without any attenuation or disturbance. We have installed very successfully using this method and can offer advice if you need it.

This transducer is best for: Metal and GRP hulls.

Not good for:  DO NOT install in a wooden hull:-

As a thru-hull fitting - swelling of the wood may cause damage to the transducer.

Installed internally the ultrasonic signal  is unlikely to penetrate a wooden hull.

For a wood hull use a Bronze version

There is a 6 pin version of this transducer, NBM40-50/200T that should be used for all Onwa chart plotter models