Vertical Card Compass?

On Sun, 1 Apr 2007 14:21:01 -0700, "Matt Barrow"
wrote:


"Ron Rosenfeld" wrote in message
.. .
On Sun, 1 Apr 2007 13:32:03 -0700, "Matt Barrow"
wrote:

I had one (PAI) in my Bo 36 for four years with nary a glitch. The
installer, IR, mentioned removing ALL magnetic interference during the
install.

In order to remove all magnetic interference in my old Mooney, I would
have
to rewire quite a bit, as well as degauss. The estimate to have this done
about fifteen years ago was well over $4,000. (Degaussing would only work
for a week or two). A compass with a remote sensor was a much more
economical solution.


What's the deal with Mooney's? Does it make radio installs more touchy?



The older Mooney's were prone to having magnetism induced in the steel cage
that essentially surrounds the cockpit area. SB M20-150A (see
http://www.mooney.com/service/service_bulletins.php ) discusses this issue.
I think it had to do with the way the earlier Mooney's were wired.
Apparently the airframe was used as a ground return path. My understanding
is that subseqent Mooney's were not wired in this manner. In addition, the
windshield center post (where the magnetic compass gets mounted) was
changed to non-magnetic stainless steel, from the original steel.

I don't believe radio installs are any more "touchy", except perhaps for
space behind the panel issues.
--ron