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
    Problems with artifical horizons
    From: Alan S
    Date: 2012 Mar 20, 13:29 -0700

    I have two of the things, one being the Davis AH, people here are likely familiar with this device.

    I also have a home made AH, first surface mirror, 10" x 10", on a levelable base. I level the assembly using a couple of string levels and reasonably fine leveling screws 120 degrees apart.

    This afternoon, I'm in the Pittsburgh area, I did a couple of sun shots with the Davis AH sitting on the ground. IE was 1.8 Min On Arc. Measured angles were 90 D 48 Min, and 90 D 25 Min, without correction. Time was around 1430, Eastern Daylight Savings Time. Nothing further wad done, that is the sights were not reduced.

    I next brought the mirror AH out for an airing. Setting is on the ground, leveling the unit, I saw reflected sun, but could not find sextant sun, that would be the sun that moves when the index arm is swung.

    I next tried setting the mirror ah on an elevated surface, using an ironing board, which is about 40" high. After leveling the assembly, I tried a sun shot, rocking the sextant while swinging the index arm. Reflected sun was visible, but alas could not find the sextant sun.

    I assume that I'm doing something wrong, but cannot figure out what that might be. Anyone here got any bright ideas or suggestions?

    Thanks in advance for same.

    Alan

    ----------------------------------------------------------------
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com
    ----------------------------------------------------------------

       
    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