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    Re: Sextant Comparisons -> to Joel Jacobs...
    From: Courtney Thomas
    Date: 2004 Mar 20, 17:39 -0500

    Joel,
    
    I should have said...I have a SNO-M, not T. Anyway, the awful olive
    color and the one scope. I got it real cheap and want to bring it up to
    snuff.
    
    I also have a more recent SNO-T which has an agreable silver color and 2
    scopes.
    
    But I obviously agree that the Russian sextants are good and a great buy.
    
    Appreciatively,
    Courtney
    
    
    
    Courtney Thomas wrote:
    
    > Joel,
    >
    > I have one and hate the color, but am otherwise satisfied.
    >
    > What is "black wrinkle paint" ? Where do I get it and how is it applied
    > for optimal esthetics ?
    >
    > Where can I get a proper scope for CELNAV ? How much ?
    >
    > Appreciatively,
    >
    > Courtney
    >
    >
    >
    > Joel Jacobs wrote:
    >
    >> Fred,
    >>
    >> Your best bet is a Russian SNO-T sextant. They are very underrated,
    >> and have
    >> most all the features of the preferred brands, and even come in a smaller
    >> size for convenience. However, most of them are sold with only an
    >> astronomical scope which presents the image inverted, and IMO are useless
    >> for CELNAV. Configured with the 7 x scope, you should be able to buy
    >> one for
    >> $250.00 because they are a drudge on the market with out an erect imaging
    >> scope. You can read about them in detail at:
    >>
    >> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3712084763&category=37971
    >>
    >> &sspagename=STRK%3AMESSE%3AIT&rd=1
    >>
    >> They wont meet your standards for good looks, but you can get some black
    >> wrinkle paint, and make them look as pretty as you like. They are a great
    >> buy.
    >>
    >> Joel Jacobs
    >>
    >>
    >>
    >> ----- Original Message -----
    >> From: "Fred Hebard" 
    >> To: 
    >> Sent: Saturday, March 20, 2004 12:15 PM
    >> Subject: Re: Sextant Comparisons
    >>
    >>
    >>
    >>> Doug,
    >>>
    >>> No, I don't collect older equipment.  I have been trying to acquire a
    >>> sextant suitable for lunar observations, so I look for sextants with
    >>> defects on Ebay that might still be serviceable.
    >>>
    >>> I have one British Husun that only has the "star scope."  It's a 2.5x
    >>> power scope.  It's my understanding that a more powerful one would give
    >>> more precise readings.  I checked this by buying an old Simex-type
    >>> sextant, which subsequently was sold.  I have been looking for another
    >>> Husun with the inverting telescope or another instrument.  The Cassens
    >>> & Plath was the first that came up which was suitable.
    >>>
    >>> In comparing the Cassens and Plath to the Husun, I would say, overall,
    >>> that I prefer the Husun at this time.  It's prettier, with the
    >>> silver-inlayed arc; this increases my fondness for the instrument.  The
    >>> black crinkle finish is nicer than the Cassens and Plath's.  All the
    >>> screws are varnished or painted brass; there's no aluminum to corrode
    >>> with steel screws or react with the brass or bronze (There's no
    >>> corrosion on my Cassens and Plath; it doesn't appear ever to have been
    >>> used for extended periods).
    >>>
    >>> The 2.5x scope on the Husun has a very wide field of view, wider than
    >>> the 4x "star scope" on the Cassens and Plath.  I have seen no optical
    >>> aberrations in the Husun, while the Cassens and Plath star scope has
    >>> chromatic aberration, which rather surprised me (reddish fringe on the
    >>> bottom of the image and bluish fringe on the top).  The aberration
    >>> makes it more difficult to check index error by measuring the sun's
    >>> semidiameter.
    >>>
    >>> The handle on the Husun is straight up and down.  This makes some
    >>> lunars easier, whereas the tilted handle on both brands of Plaths,
    >>> while it makes looking at the horizon easier on the wrist, makes lunars
    >>> more difficult.  When holding the instrument between shots or while
    >>> waiting, the Husun is less fatiguing to hold
    >>>
    >>> The star scope on the Husun is in close to the horizon mirror.  This
    >>> centers weight in the instrument, making it less fatiguing to hold.
    >>> Being close in to the horizon mirror, the smaller mirror does not
    >>> restrict the field of view of the instrument as much as one might
    >>> suppose.  I suppose the larger mirrors would be "faster" optically,
    >>> however.
    >>>
    >>> The perceived weight of the two instruments is similar.  I have not
    >>> actually weighed them.
    >>>
    >>> The lamp on the Husun can be swung around to illuminate my wrist band
    >>> when recording data.  The lamp on the Cassens and Plath is guided to
    >>> illuminate the scales only, making recording data more difficult.
    >>>
    >>> The box on the Husun is significantly smaller than the box on the other
    >>> instruments.
    >>>
    >>> These are my impressions after two days.
    >>>
    >>> Fred
    >>> ------------------------------------------------------------------------
    >>> Frederick V. Hebard, PhD                      Email: mailto:Fred{at}acf.org
    >>> Staff Pathologist, Meadowview Research Farms  Web: http://www.acf.org
    >>> American Chestnut Foundation                  Phone: (276) 944-4631
    >>> 14005 Glenbrook Ave.                          Fax: (276) 944-0934
    >>> Meadowview, VA 24361
    >>>
    >>> On Mar 19, 2004, at 5:44 PM, Royer, Doug wrote:
    >>>
    >>>
    >>>> By the way,do you collect older sextants?Don't you also have some older
    >>>> British equipment you wrote about in the past?Just curious.
    >>>>
    >>
    >
    >
    > --
    > Courtney Thomas
    > s/v Mutiny
    > lying Oriental, NC
    > WDB5619
    >
    
    
    --
    Courtney Thomas
    s/v Mutiny
    lying Oriental, NC
    WDB5619
    
    
    

       
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