Thread: Humminbird 899 Side Image Transducer.

There is a kind of misnomer about the stock XNT 9 SI 180 T in the forum conversations and it not being able to take advantage of the 800kHz frequency like the XHS 9 HDSI 180 T upgrade xducer ...

Both xducers have the same amount of SI piezoes (1 left and 1 right) ...

The difference is ...the piezoes in the XHS 9 HDSI 180 T are manufactured by design to efficiently vibrate at 455kHz and 800kHz ...

The piezoes in the XNT 9 SI 180 T are only designed to efficiently vibrate at 455kHz ...

The 899ci SI has 2 separate SI frequency functionality possibilities that tell the SI transmitters what frequency(s) to send to the SI piezoes ...:

*The "HiDef Sidescan" Transducer Select menu setting tells the SI transmitters to fire at 455kHz or 800kHz (dependent on the "Image Frequency" setting under the sonar tab) ...

*The "Sidescan" Transducer Select menu setting tells the SI transmitters to fire at 455kHz (the only "Image Frequency" menu setting when the Transducer Select menu is set to "Sidescan") ...

If the stock XNT 9 SI 180 T is connected to the 899 ... And the "Transducer Select" menu is set to "HiDef Sidescan" = the SI transmitters can fire at 455kHz and 800kHz ...but the SI piezoes in the XNT 9 SI 180 T will not vibrate efficiently when the "Image Frequency" is set to 800kHz ...

The SI transmitters will send the 800kHz signal ... And the SI piezoes will vibrate with the 800kHz frequency signal ... Just not efficiently ....

Clear as mud ...??

Rickie