Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Sextant Comparisons -> to Joel Jacobs...
    From: Courtney Thomas
    Date: 2004 Mar 20, 17:05 -0500

    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
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site