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: Periscopic Sextant. Henry Hughes and Son
    From: Gary LaPook
    Date: 2009 Jul 31, 09:44 +0100
    You're right, the electronic averger on the later models of the Kollsman periscopic sextants eat batteries,  A year or two ago I posted a way  to make a power supply that steps up 12 volt to 28 volts using one integrated circuit and one resistor, total cost about 25 bucks. You can search for it in the archive. If you don't mind being tied to an extension cord, an inexpensive way to get 28 volts AC is to buy a transformer for a lawn sprinkler which put out 28 volts AC.  The sextants work on either AC or DC.

    gl

    MikeN wrote:
    I have a USAF type periscopic Kollsman D-1 sextant that requires 28
    volts for the averager to work.  I tried wiring three 9-volt batteries
    in series but the averager needed more power than the three batteries
    provided.  I then copied the arrangement twice and then wired the
    three series of three in parallel and it worked.  However, there's
    significant power drain and the thing is only good for 2 or 3 shots.
    
    Mike Nelson
    Herndon, VA
    
    On Jul 29, 6:58 pm, <douglas.de...{at}btopenworld.com> wrote:
      
    Sorry not to reply until now. I have only just found you request. I only look infrequently here.
    
    Mine is a MkI Hughes periscopic. I would expect them to all have the same connections with later Mark sextants.
    There are three pins in a socket, the centre pin being common (Case, earth).  When looking at the pins from the back of the sextant (eyepiece away from you) the left pin is 3V for the bubble lighting, and the right pin is 28V DC for the averager motor. In fact it works from about 12V upwards.
    
    I have a battery holder for two 1.5V cells which plugs straight into the socket enabling the sextant to be used for single shot sights, hand held, (heavy!) but without the averager. In fact I stand it on a suitable surface at the right height.
    
    I have powered the averager from a separate power supply to check it and for the fun of it, but do not use it in anger for sights.
    
    The power arrangements were designed for use with the aircraft fuselage mounting and power supply when connected of course.
    
    Douglas Denny.
    Chichester England.
        
    
    
      


    --~--~---------~--~----~------------~-------~--~----~
    NavList message boards: www.fer3.com/arc
    Or post by email to: NavList@fer3.com
    To unsubscribe, email NavList-unsubscribe@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