location of fluxgate

[sailon1]

Does anyone know of the adverse effects that would occor if I located the fluxgate compass on the interior wall of the lower portion of the galley sink area? The hot water heater would be a few inches away.I have checked previous postings on locating the compass of the ST4000 and found no mention of this area. Any feedback would be appreciated.

[vmenasce]

There are two heavy current draw items under the sink. One is the pump for the fresh water. The second is the wiring for the refrigerator. The wiring for the fridge is actually hidden below the floor boards. Both will cause a significant magnetic deviation when operating. I don't expect the water heater to be a problem. It is not an electrical appliance unless connected to shore power. At that point I assume you won't be using the auto-pilot. The effect of the water pump and refrigerator will be significant. I recommend the hanging locker in the aft cabin as a good location for the compass. It is far away from any wiring and it is easy to fish the wire from the binnacle down behind the rear bulhead and across to the hanging locker. Keep it down low so as to minimize the effect of rolling and pitching.