Page 1 of 2 12 LastLast
Results 1 to 10 of 13
  1. #1
    Join Date
    Jun 2004
    Posts
    82

    Default Freiberger Drum Sextant

    Continuing with my spending on the great EBlag (subject to approval from the Boss of course ) I am now the proud owner of a 1975 Freiberger Drum Sextant! Only problem is that I have the Owners Manual/Guide in French and German only (courtesy of the web). Don't suppose anyone has an old English version or could scan and email? I have visited the Freiberger website but they don't appear to provide old manuals as far as I can see.
    Better to have a lived a day as a tiger than a thousand years as a sheep

  2. #2
    Join Date
    Jul 2009
    Posts
    19,519

    Default

    I have a Freiberger 'Yacht' sextant with a 'Description-Adjustment-Operation' booklet in English.

    You are welcome to a photocopy of it if you pm me with your email address.

  3. #3
    Join Date
    Mar 2007
    Location
    Paris France
    Posts
    310

    Default Who to en joy Arabia

    Use spare time to earn French... or German !
    Eric
    Pourquoi faire simple quand on peut faire complique ?

  4. #4
    Join Date
    Jun 2004
    Posts
    82

    Default

    I am very proud of my linguistic abilities...............I can ask for a beer, food and somewhere to lay my head pretty much anywhere in the world. One of the benefits of being an expat is I regularly encounter Spanglish in its many forms and no matter how linguistically challenged the group may be the meaning is generally understood ). Unfortunately, being able to get by in a drunken bar crawl anywhere in the world does me no good when trying to decipher a manual (bearing in mind as a red-blooded male I make it a point to avoid reading instructions until absolutely necessary!)
    Better to have a lived a day as a tiger than a thousand years as a sheep

  5. #5
    Join Date
    Sep 2013
    Posts
    1

    Default

    Quote Originally Posted by c2518 View Post
    Continuing with my spending on the great EBlag (subject to approval from the Boss of course ) I am now the proud owner of a 1975 Freiberger Drum Sextant! Only problem is that I have the Owners Manual/Guide in French and German only (courtesy of the web). Don't suppose anyone has an old English version or could scan and email? I have visited the Freiberger website but they don't appear to provide old manuals as far as I can see.
    Hi, Maybe it is far too late, but I only came across this website today while looking for the same sextant because I own one, too now and have original instruction manuals, one in German and one in English. I'd be happy to scan the English one for you and email it to you. Just drop me a note. rengis2001atyahoo.co.uk

  6. #6
    Join Date
    Jan 2016
    Posts
    1

    Default Re: Freiberger Drum Sextant

    Hi co256
    If you have that scanned Freiberger manual in English, I would be most grateful for a copy to Nick-stanton@hotmail.co.uk

    Kind regards
    Nick

    Nick

  7. #7
    Join Date
    Oct 2012
    Posts
    3,248

    Default Re: Freiberger Drum Sextant

    I have a Friebergerer. Its a nice setant.
    I dont have a manual. But I can post how to check and adjust one and if you have any questions i can try and aswere them.

    Sorry I dont know how to post picturse of diagrams
    Last edited by Uricanejack; 30-01-16 at 21:10.

  8. #8
    Join Date
    Oct 2012
    Posts
    3,248

    Default Re: Freiberger Drum Sextant

    There are three adjustable errors in a sextant.
    The first error of a sextant is perpendicularity
    Perpendicularity error is due to the plane of the index mirror not being perpendicular to the plane of the sextant.
    The method to check for Perpendicularity error is to set the arm approximately mid arc and hold the sextant with the arc away from you at arm’s length. Look into the index mirror the true and reflected image of the arc should appear as a continuous arc.
    This can be adjusted by moving the screw on the outside edge of the index mirror furthest from the plane of the sextant until the true and reflected arc’s appears as one continuous arc.
    The second Error of a sextant is side error.
    Side error is due to the plane of the horizon mirror not being perpendicular to the plane of the sextant.
    There are three methods to check for side error.

    Side error Method 1
    Set sextant arm and micrometer to zero.(for all methods)
    Observe a distant small object. Both the true and reflected image should be seen as one image or ina vertical line. If they are not in a vertical line there is a side error present.
    Method 2 (probably more accurate than method 1)
    Set at zero. Hold sextant horizontally instead of vertical and observe a distant straight edge or line.
    The true and reflected images should appear as one straight line. If not a side error is present.
    Method 3 same as above use the horizon if nice and clear(better)
    Method 4 (best or preferred)
    Set sextant to zero. Observe a star. The true and reflected image star should appear as one image or as two in vertical line. If not side error is present.
    Side error can be adjusted by turning the screw of the horizon mirror furthest from the plane of the sextant.

    Perpendicularity and side error can not be measured
    The third error of a sextant is index error.
    Index error is due to the plane of the index horizon mirror and the plane of the index mirror not being parallel when the sextant is set at zero.
    There are three main methods to check for and measure index error.
    2 methods require sextant to be set to zero.
    Method 1.
    Set sextant to zero.
    With the sextant held vertically Observe a distant small object or line. The true and reflected images should appear as one. If they do not there is an index error present. One image is above the other.
    To measure the index error adjust the micrometer until the true and reflected images are one image.
    Read the arc and micrometer.
    If the sextant reads less than zero the error is known as off the arc.
    If the sextant reads more than zero the error is known as on the arc
    A small error will always be present. If small, measured and known accurately index error can be allowed for.
    If error is off the arc it should be added if the error is on the arc it should be subtracted.
    Method 2 is to use the horizon if nice and clear(better).
    Method 3 is to use a star(most accurate)
    Index error can be adjusted by turning the screw on the horizon mirror closest to the plane of the sextant it is on the upper edge of the horizon mirror.
    Adjusting the index error will almost always cause a side error. After adjusting for index error side error should be rechecked and adjusted. This will cause an index error.
    Repeat until only index error appears and measure the index error.
    A 4th common method to measure index error (often an exam question) by measuring or observing the diameter of the sun.
    Set the sextant to 32 minutes on the arc.
    Observe the sun( through shades). There should be two images one above the other in a vertical line
    Adjust micrometre until both the true and reflected suns upper and lower limb(edge) just touch.
    Read the sextant and note the reading.
    Set the sextant to 32 minutes of the arc(micrometer reads backwards)
    Repeat the above. And note the sextant reading.
    Add both readings together.
    Divide the sum by 4.
    Compare the result to the semi diameter of the sun listed for the day in the nautical almanac.
    The difference is the index error.
    The index error should be checked before taking a sight.

  9. #9
    Join Date
    Dec 2006
    Posts
    8

    Default Re: Freiberger Drum Sextant

    Quote Originally Posted by parsifal View Post
    I have a Freiberger 'Yacht' sextant with a 'Description-Adjustment-Operation' booklet in English.

    You are welcome to a photocopy of it if you pm me with your email address.
    Parsifal... would you mind sending me a copy of your manual if you still have it??

    Many thanks

  10. #10
    Join Date
    Jan 2018
    Posts
    2

    Default Re: Freiberger Drum Sextant

    Quote Originally Posted by parsifal View Post
    I have a Freiberger 'Yacht' sextant with a 'Description-Adjustment-Operation' booklet in English.

    You are welcome to a photocopy of it if you pm me with your email address.

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Latest YBW News

Find Boats For Sale

to
to