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: Timekeeping in the post-WWV/post-HF world
    From: Murray Peake
    Date: 2018 Sep 25, 23:49 -0700

    On the subject of high-accuracy watches, I bought a Longines VHP 1000 Oe Quartz watch a few years ago (secondhand online) , and when I checked this morning it was 32 seconds slow - it's at least 4 years since I set it, so it is within spec.

    A very cheap option available until recently was the Texas Instruments eZ30 Development Tool which is a bit of circuitry TI packaged as a sports watch with the interesting features that it has a wifi interface and programming capability. Out of the box accuracy was poor - mine drifted 15 seconds or so a day. However there was a project which I followed and implemented where a third party programmed the Version 3 HAQ-ezChronos firmware which allowed the watch to be calibrated at a number of temperatures, a parabola fitted to the quartz frequency against temperature, and the watch display adjusted to compensate. Setting was by wifi from a PC with recently set internet time. I did a rough compensation and the accuracy was very acceptable. Mechanically the watch was a bit primitive (it was just a development kit) and mine didn't survive a battery change. Interesting idea though.

    Regards

    Murray

       
    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