Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!bu-cs!purdue!decwrl!labrea!kestrel!king
From: king@kestrel.ARPA (Dick King)
Newsgroups: sci.electronics
Subject: Re: Depth Finder Problem
Message-ID: <46387@kestrel.ARPA>
Date: 29 Dec 88 16:15:59 GMT
References: <8812271430.AA18210@decwrl.dec.com>
Reply-To: king@kestrel.UUCP (Dick King)
Organization: Kestrel Institute, Palo Alto, CA
Lines: 22

In article <8812271430.AA18210@decwrl.dec.com> starin@abe.dec.com (Mark Starin KB1KJ DTN: 264-5596 MK01-1/A10) writes:
>I am posting this for a friend at DEC.
>
>The depthfinder on his sailboat works fine when he's under sail. 
>However, as soon as he lights off the "iron main", the depthfinder 
>indicator starts giving messed up indications.
>
>The depthfinder is located 3-4 feet from the engine and is 
>apparently well grounded. According to him, it is connected directly 
>to the battery - not to the alternator system.
>
>Any assistance would be appreciated.

The problem is probably the engine's noise rather than any electrical
problem.  A depth finder is, i believe, a sonar device.

Is it possible to lower the transducer into the water on a string to
test whether this is the case?  If so, the transducer should probably
be moved to somewhere far from the engine.



-dk