NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: planned purchase astra IIIB
From: Greg R_
Date: 2007 Jan 28, 15:35 -0800
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From: Greg R_
Date: 2007 Jan 28, 15:35 -0800
Hi Jehaes:
Please address your replies to the List itself
and not just to me personally. Thanks.
> Do not move the horizon mirror because you
have a lot of "chance" to
> introduce a lot of errors : both mirrors must be fully parallel and in
> the same plan. Not so easy to adjust.
> introduce a lot of errors : both mirrors must be fully parallel and in
> the same plan. Not so easy to adjust.
I disagree - I've swapped out the mirrors
numerous times with no problems.
The holes in the mirror are somewhat wider than
the screws themselves, which gives plenty of room for a "rough" index adjustment
with the index/micrometer set to zero (a sea horizon, or any other distant
horizontal surface works fine for this). Any remaining "fine" index adjustment
can be done with the adjusting screws on the mirrors themselves, and side error
can be adjusted in the usual way with a star, planet, or even the sun itself.
Like I said earlier, I'm getting accuracies in
the ~1-2 NM range (with both sets of mirrors) so I must be doing something
right... ;-)
--
GregR
----- Original Message -----
From: "Jehaes" <andjehaes@belgacom.net>
To: "Greg R." <gregr_ingest@yahoo.com>
Sent: Sunday, January 28, 2007 3:21
PM
Subject: Re: planned purchase astra
IIIB
Do not move the horizon mirror because you have a
lot of "chance" to
introduce a lot of errors : both mirrors must be fully parallel and in
the same plan. Not so easy to adjust.
André Jehaes
introduce a lot of errors : both mirrors must be fully parallel and in
the same plan. Not so easy to adjust.
André Jehaes
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To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
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