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
    Name or NavList Code:
    Email:
       
    Reply
    Re: Is this a "digital sextant"?
    From: David Pike
    Date: 2019 Aug 17, 14:32 -0700

    You can waggle the pictures up and down within the frame.  Doing so shows much more 8 lead rainbow ribbon cable and what looks like a SCART connector. The gearing from the micrometer is only 1:1, so the round things are probably incremental rotary encoders, one for the arm and one for the micrometer drum.  Early Acorn PCs didn’t become available until around 1980, so notwithstanding the date on the calbration certificate, this device might be more 80s than 70s.  I visited the Admiralty Compass Observatory at Teddington around 1980 to swap a Watts Datum Compass and was invited to have a look around while I was there.  There were all sorts of interesting experiments going on in the labs.  This looks like an experiment to digitise the arm and micrometer drum measurement for processing within an early PC, possibly a BBC or Acorn Atom. The OOW might use the Admiralty Pattern sextant as per normal, but the output from the encoders would be fed to an incremental encoder interface to give absolute position and then to a PC.  Then anything might be possible depending upon the programme:  instant observations; observations when a button was pressed; or continuous averaging.  Timing would have been no problem once set in the PC, and sight calculation within the computer might also have been intended.  DaveP

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

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

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

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

    Email Settings

    NavList ID 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