NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: George Brandenburg
Date: 2012 Nov 20, 12:20 -0800
Just an amusing sidelight. On our sailboat I wanted to position my Garmin chart plotter (model 546) a little lower, which brought it closer to the compass housing. However, I had noticed in an appendix to the Garmin manual that it said it shouldn't be mounted within 50cm of a magnetic compass. When I tested this, I saw significant compass deviations when the GPS was brought near, and this was the case whether or not the GPS was turned on! I had been expecting to see a much smaller effect, if any, from the active GPS circuitry, but was quite amazed and disappointed that the device was intrinsically magnetic!
I googled it to find out what others had discovered, and it turns out the problem is amazingly simple, and if I may say so, stupid. There is a small slot for an SD card on the face of the GPS, and it has a little watertight door over it that is held closed by, you guessed it, a permanent magnet. What were they thinking!!
George B
----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------