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> I own quite a few metal sextants, and my measurements
> indicate that Tamaya
> and Plath are more accurate than the Astra.  I have seen used
> Tamaya Jupiter
> sextants sell for about the same as an Astra IIIb and I think
> I would prefer
> a Jupiter over an Astra given the choice, but you will be
> quite happy with a
> new Astra as well.

Celestaire's brochure gives 20" of accuracy for the Astra IIIB against 12"
for the Jupiter. I wish the Astra IIIB had a bronze arc, if that's the
secret in the reduction of precision.

I've always wondered: how accurate is a good sextant user? I mean, is 20"
going to be a limiting factor? That's an error of about 1/3 of a mile
compared to 1/5 mile for the Tamaya Jupiter, right?

YA

P.S.: Dan, while reading your thread about your sextant accuracy at
http://www.i-DEADLINK-com/lists/navigation/9903/0042.html you're mentionning Tom
Metcalf's nav.c. Where can I find that and the relevant litterature? Do I
need to get back issues of the journal of the institute for navigation?

Another question related to what you wrote there: how's the Davis artificial
horizon compared to the practice bubble horizon sold by Celestaire?

   

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