Magnetic shielding

Steve Freeman wrote:
I need to mount a compass on the instrument panel glare shield. There
is magnetic interference in most all of the areas that are best for
viewing the compass. Anyone know anything about the various forms of
magnetic shielding available now. On one site alone they sell over 5
different types of material. A compass manufacturer once recommended
this as an easy solution to interference in a power plane but it was a
few years ago and I do not remember the material we used.

Here's one approach you could consider. Most deviation arises from wires
within 3 inches of the compass.
If wires cannot be routed further than 3 inches away, and every inch
counts, most deviation can be squashed by providing closely twisted
pairs for current carrying wires.
They don't even have to have the same twist over the whole length, so
if done judiciously, a pair of wires could be twisted with a tourniquet
and secured with this twist. Placing the tourniquest as far from the
compass as possible will improve things best.

Brian W

On Jul 19, 8:00*pm, brian whatcott wrote:
Steve Freeman wrote:
I need to mount a compass on the instrument panel glare shield. There
is magnetic interference in most all of the areas that are best for
viewing the compass. Anyone know anything about the various forms of
magnetic shielding available now. On one site alone they sell over 5
different types of material. A compass manufacturer once recommended
this as an easy solution to interference in a power plane but it was a
few years ago and I do not remember the material we used.

Here's one approach you could consider. Most deviation arises from wires
within 3 inches of the compass.
If wires cannot be routed further than 3 inches away, and every inch
counts, most deviation can be squashed by providing closely twisted
pairs for current carrying wires.
* They don't even have to have the same twist over the whole length, so
if done judiciously, a pair of wires could be twisted with a tourniquet
and secured with this twist. Placing the tourniquest as far from the
compass as possible will improve things best.

Brian W

On Jul 19, 8:00*pm, brian whatcott wrote:
Steve Freeman wrote:
I need to mount a compass on the instrument panel glare shield. There
is magnetic interference in most all of the areas that are best for
viewing the compass. Anyone know anything about the various forms of
magnetic shielding available now. On one site alone they sell over 5
different types of material. A compass manufacturer once recommended
this as an easy solution to interference in a power plane but it was a
few years ago and I do not remember the material we used.

Here's one approach you could consider. Most deviation arises from wires
within 3 inches of the compass.
If wires cannot be routed further than 3 inches away, and every inch
counts, most deviation can be squashed by providing closely twisted
pairs for current carrying wires.
* They don't even have to have the same twist over the whole length, so
if done judiciously, a pair of wires could be twisted with a tourniquet
and secured with this twist. Placing the tourniquest as far from the
compass as possible will improve things best.

Brian W

On Jul 19, 8:00*pm, brian whatcott wrote:
Steve Freeman wrote:
I need to mount a compass on the instrument panel glare shield. There
is magnetic interference in most all of the areas that are best for
viewing the compass.

There is a very good and experienced pilot at our field who went to
the local auto parts store and bought a "glass marble" type compass
that he uses in his glider. It's a compas contained in plastic sphere
about 1" in diameter. I guess he paid no more than $5 for it. He
made a small mount for it and velcro'd it on the inside of the canopy
in the same spot where his yaw string is attached. Pretty neat setup
and very inexpensive. Also solves the problem of being far enough
away from the panel where potential magentic fields exist.