Join Date: Jun 2007
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GPS Sonar vs. Depth Finder: Interference?
Bought a Garmin 498 GPS/chartplotter/sonar, with in-hull transducer. The transducer is an Airmar P79. Little did I know, at the time, that the PO of my boat had upgraded the depth sounder to a Raymarine unit, including, you guessed it, an Airmar P79 transducer. Naturally he installed the depth sounder's transducer right where the instructions said to. (Or as close as possible, given access restrictions.) Now I'll be doing the same, and installing the sonar's transducer directly on the other side of the keel--or so close as the difference makes no nevermind. The Raymarine depth sounder is appearantly running its transducer at 200KHz. Unless there's some magic involved here, I imagine I won't be able to run the sonar at 200KHz, otherwise they'll interfere with one another and neither will give readings worth spit. So it would appear I'll have to run the Garmin sonar at 50Hz, right? Will I get any kind of worthwhile picture of the bottom that way? I'll be in shallow, sometimes very shallow, water.