Connect with us

Metal detector recommendations?

Discussion in 'General Electronics' started by Bruce W...1, Oct 20, 2003.

  1. Bruce W...1

    Bruce W...1 Guest

    I've always wanted a metal detector. Not so much for treasure hunting
    but for utility purposes like maybe tracing a buried wire, tracing a
    conduit in a wall, finding the bolt I just dropped in the lawn, that
    sort of thing.

    I know more about ground penetrating radar than I do about consumer
    metal detectors. On ground penetrating radar I know that, for my
    purposes, I can't afford it.

    Metal detectors, to my knowledge, were first used in WWII. From an
    appearance standpoint I don't see much difference from current consumer
    model. Has there been any evolution?

    I find metal detectors that sell from between $50 and $300. Is there
    much of a difference? Do lots of LED's or analog meters serve much
    purpose? Can they really detect different types of metals?

    What is the state of the art of metal detectors? What do they do well,
    and not so well? What is their detection range in dirt?

    Can you make any recommendations on a good model? Does one stand above
    all others today?

    Thanks for your help.
     
  2. Robert Baer

    Robert Baer Guest

    There are various designs, crudely put into 2 classes:
    a) transmitter coil perpendicular to receiver coil, typically a harness
    over the shoulders is used, with one coil in front, and the other in the
    rear. I think Fisher was the first with this design, and this is good
    for pipes and other large objects in the ground and goes fairly deep as
    i understand.
    b) both coils are in one circular "pad" at the end of a stick ling
    enough to use as a ground scanning wand.
    This is the class of detector you want, but there are many variations,
    from low frequency to unstated but not low frequency. Some use square
    waves, some use pulses, and some use sine waves.
    Many of the modern ones use a microprocesor to interpret phase shift
    and signal loss in order to better "discriminate" between one metal and
    another.
    The two best makers are White and Garrett.
     
  3. a good starting point may be :

    http://www.thunting.com/cgi-bin/geotech/pages/common/index.pl?page=main&file=main.dat

    a lot of stuff and schematics are there

    Best regards
    Tsvetan
     
  4. P A U L

    P A U L Guest

    Do metal detectors based on 360deg. rotating magnetic pulsed fields
    (in several individual transmission loops surrounding the receive
    loop) to find direction exist?

    In fact what i think of is a transposed magnetic principle of the
    system used in radio location "doppler scan antenna direction finding
    system".
    Several magnetic transmission loops (8) on the outside (switched in
    sequence) and a central reception loop overlapping halve the
    transmission loops (to avoid as much as possible transmitter/receiver
    signal interception).
    The relative phase of the outside loop switching versus the received
    signal provide the metal sloop distance direction.

    Paul
     
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-