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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@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.

   

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