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>Lee wrote:
>
>> George, I don't understand what you are saying here, and wouldn't mind a
>> reference or source  to help develop what you are saying. My imperfect
>> understanding at the moment is that the only difference between a zoned and
>> a global needle is the bearing that the needle/card rides on. As I
>> understand it, a global needle is based upon a more intricate and expensive
>> bearing. A bearing that allows the needle to swing freely, despite the
force
>> of magnetic dip upon it. Properly built, it is unclear to me that a global
>> needle will function any different to a zoned needle.
>
>That suggests a fourth compass design, perhaps involving a roller
>bearing around the pivot pin which would allow the card to rotate but
>not to tilt at all. Are such things made?

Suunto is making several handheld compasses with a "global" needle.
Evidently, they've come up with a design where the magnet and the needle
are separate, so that the magnet can tilt while the needle lies flat. If
you put "suunto" and "global" in Google, you can read all about them. Here
is one of them:

http://www.amronintl.com/tactical/products.cfm?id=1089

                Greg Travillian
                gregtravillian@alltel.net

   

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