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Old 02-09-2011, 02:49 PM   #12
Bear Islander
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Quote:
Originally Posted by Woodsy View Post
BI...

I find it hard to believe that your depth finder (sonar - sound waves) goes off when your boat was painted with radar (microwaves). Especially considering your sonar transducer is located under the waterline of the boat in either the bilge (internal) or external on the transom....
RADAR guns put out a lot of energy and can interfear with all kinds of electronic equipment.

I'm not suggesting the underwater transducer picks up the RADAR directly. However the lead from the transducer to the depth finder in the dashboard is very high impedance. And is mostly above the water line. It therefore is susceptible to RFI from The RADAR gun.

The depth finder interprets the RFI hash as multiple depths and the shallow-water alarm is triggered.
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