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    Re: C.Plath on Ebay
    From: Alexandre Eremenko
    Date: 2005 Jun 10, 15:01 -0500

    In Russian sextants, collimation adjustment is
    not a feature of the sextant, but a feature of the scope.
    I have never seen an SNO-M in real life, but from the pictures
    I conclude that they come with two kinds of scopes.
    (Like SNO-T). It is the UNIQUE Russian INVERTING SCOPE
    which has the collimation adjustment.
    I have not seen ANY other scope like that, and I wonder why
    all Call Nav books still mention this adjustment
    (which cannot be made on anything but this Russian inverting scope).
    
    All kinds of Russian sextants and scopes that I know can be seen in
    http://www.maurnavy.com/index.html
    Picture 2 shows an SNO-M with inverting scope (which has collimation
    adjustment).
    Picture 1 shows an SNO-T but with ordinary (straight) scope.
    (New SNO-T come with two scopes: ordinary and inverting)
    Picture 4 shows some old sextant resembling SNO-M with
    some old scope (possibly inverting)
    which also has the collimation adjustment,
    but this is not the modern inverting scope.
    
    
    On Fri, 10 Jun 2005, Courtney Thomas wrote:
    
    > Then the SNO-M does not have the collimation error adjustment ?
    >
    > Thank you,
    > C.Thomas
    >
    >
    > On Fri, 2005-06-10 at 02:05, Alexandre Eremenko wrote:
    > > Yes, of course.
    > > This picture could be used in a beginner's
    > > textbook to explain what is "collimation error":-)
    > > Modern sextant scopes (for the reasons that excape me)
    > > do not have collimation error adjustment,
    > > with one exception: the inverting scope of SNO-T.
    > > Once Bill suggested to adjust collimation error
    > > with a hammer...
    > >
    > > This is apparently what the owner of this sextant did,
    > > and after he failed, he sells the sextant:-)
    > >
    > > Alex.
    > >
    > > On Thu, 9 Jun 2005, Robert Eno wrote:
    > >
    > > > Have a look at this sextant on e-bay.
    > > >
    > > > Are my eyes deceiving me or is the rising piece on the scope bent out of shape?
    > > >
    > > > http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&category=37971&item=7328115519&rd=1
    > > >
    >
    
    
    

       
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