Compass trouble

In article nrp writes:
Might it be possible to kludge a degausser? I'm looking for a
volunteer to try this scheme:

1) Get a 500 ft length of 4 conductor (3 conductor plus ground) # 14
AWG Romex still in the box coil.

2) Configure/connect the ends to make it a 2000' long single wire
bundle of about 400 turns.

3) There should then be enough resistance in the wire to plug it into
the 110 V 60 Hz line for short periods.


With a bit over 23 amps from the resistance (5.05 ohms), you will need to
hope the inductance will limit the current, or the breaker on any normal
120 volt AC source will trip pretty quickly.

A bit over 2700 watts will warm it up pretty quickly, too.


4) Remove the compass. With the power on, sweep the airplane
anywhere there is steel, and then step back several feet before
turning power off. Reinstall the compass.


You might want to remove the magneto as well. There are almost certainly
other magnetic parts in the instruments that you want out of there first --
no sense destroying the instruments in the panel. Any permanent magnet motors
will not appreciate it. In fact, anything with a coil to pick up energy from
that field could well be damaged. The alternator and connected parts may
not like this.


As with old shadow mask color TV degaussing, do it fairly slowly, and
step back fairly slowly. Turn the coil horizontal then turn it off.


No warranty. Don't wear any watches. Remove all credit cards etc
from your billfold..........

You should expect this to break something expensive.


Alan

You should expect this to break something expensive.

Alan

I agree you are very possibly right.

However, I don't think an alternator would be bothered in that it
doesn't need any magnetism to start. Magnetoes might be another story
& would require an experiment. Obviously remove all radios as a
precaution too.

Do you have any feeling as to just how powerful a degausser this might
be? If it is too powerful, operating it more remotely would allow a
more general degaussing. How close to a 4130 steel tube would it have
to be to demagnetize for example? Another experiment......

At least the wire coil could be reused to wire a house or hangar etc
as long as it isn't allowed to get too hot. A ballast such as a
toaster/iron or other high current device is series could limit the
current and degaussing power.

This is not rocket science.. A 120 volt solenoid can be used as a
degausser, as can the ones used for TV's... Even small ac motors will
have a pretty good induction field - esp. if you can open the metal
case up... The way to test is to magnetize a screw driver and then
use your degausser to demagnetize it... If it will do that it will do
the airframe...

Start with it right against the metal and run it back and forth across
the surface gradually increasing the distance away from the metal
until you are at least a foot away...

denny