Humminbird Side Imaging Forums

Side Imaging Forums => 1197c SI, 1198c SI & 1199ci HD SI => Topic started by: LittleGazoo on March 09, 2012, 08:08:02 PM

Title: Transducer level?
Post by: LittleGazoo on March 09, 2012, 08:08:02 PM
How can I insure that my side-scan transducer for my 1197(console) and 998(trolling-motor) are level in use?

Can you not observe side-scan image when passing near bridge supports?

Thanks
Title: Re: Transducer level?
Post by: sonar2000 on March 10, 2012, 10:43:34 AM
If you have a water line on the boat you can during a trailer of the boat level the boat using the water line and then check the transducer level..

Unless it is way off level then it is a bit hard to make that determination on the water..
Front to back is different than port to starboard.
Front to back may show bottom readings off kilter or induced cavitation clutter..
Port to starboard is a bit different and can be sometimes the sources of surface clutter on one side of the SI.

Chuck
Title: Re: Transducer level?
Post by: Humminbird_Greg on March 26, 2012, 05:43:04 PM
You can usually get real close by observing the shadow angle of a straight pole or bridge piling.  If the shadow does not stick straight out at a 90 degree angle than the transducer is tilted too far up or too far down.
Title: Re: Transducer level?
Post by: sonar2000 on March 26, 2012, 05:57:04 PM
Never noticed the shadow before.  Will have to check on this.

Another way is compare left and right displays. If there is a tilt one side will be showing clearer targets than the other..

 
Title: Re: Transducer level?
Post by: LittleGazoo on March 27, 2012, 11:12:59 AM
Thanks Greg,

A little more help needed.

A 30-40 foot deep bridge piling should be slightly tilted toward the top as the sonar reflection will be returning from a closer range?  Seems I read this long time back, but never found URL again.

If piling is tilted indicating transducer is a bow-tilt or stern-tilt.  We should be able to tell tilt direction from the sonar display?   Would a bow-tilt sonar display a right-lean or a left-lean?

Thanks
Title: Re: Transducer level?
Post by: Humminbird_Greg on March 27, 2012, 11:55:04 AM
LG,
A perfectly vertical bridge piling or a pole should display a perfectly horizontal shadow in the Si sonar.

If the back end Si transducer was angled downwards (pointing forwards), than the shadow will be skewed towards the top of the display because the bottom part of the Si sonar beam will contact the piling first and the resulting shadow will angle towards the top of the display (new Si sonar data).

If the back end Si transducer was angled upwards (pointing backwards), than the Opposite will happen and the shadow from the piling will be angled towards bottom of the Si display window.

Attached is a file I did on Si transducer twist (forgot I had this).

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