Originally Posted by
stevef
Some 35-40 years ago we had a Gardan Horizon GY80 in the hangar with a massive compass indication problem. The chief engineer wrapped the fuselage with the extension cables of two 2kw heaters all day (and it was summertime) in a bid to degauss it. Didn't work as far as I remember.
That would only have a (slim) chance of working if the cable/path was split so only one current carrying leg was wrapped around the fuselage, else the current induced magnetic fields cancel.
The other problem is that degaussing works by saturating the steel (both ways due to AC) then gradually reducing the strength, in the case of passing an item through the coil this happens as the distance increases.
More than a few seconds at full intensity is unlikely to change things, a sudden switching off could leave parts more magnetised than at the start depending on where in the 60/50Hz cycle the break happened.
BTW: Degaus would not work with DC in the coils.