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Old 04-02-2004, 02:39 PM
E Fitzgerald
Join Date: Mar 2004
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Default RE: Testing a fishfinder?

Melnic - when you tested and saw that the "distance was about 4.5x the actual distance" it was because the speed of sound in air is about 4.5 x slower than the speed of sound in water. Therefore your sounder "thinks" that the wall is on the other side of the rose bushes,..........

Also, when you test in air, the impedance of the transducer appears different (typically lower) than when the transducer is in water. With this in mind I would not operate a sounder with th transducer out of water for more than a minute or two at a time.

E Fitz
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