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: Test your magnetic compass.
    From: Ken Muldrew
    Date: 2012 Nov 16, 16:01 -0700

    On 2012-11-16, at 2:55 PM, Bill Morris wrote:

    Can some physicist or power engineer explain how an alternating current can produce a constant magnetic field? Could corona discharge really account for the observation or must we postulate rusty joints in transmission towers acting as rectifiers?

    AC power lines produce AC magnetic fields, but you have to be within about a meter of the line for the strength of the B field to equal that of the earth. DC power lines are becoming more popular due to advances in power engineering. Currently there are only about one or two hundred DC high voltage lines worldwide but this number will increase soon (at least power companies seem to be marketing the safety of DC lines pretty aggressively, and they do make sense for technologies such as wind power).

    Ken Muldrew.
       
    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