• If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Announcement

Collapse
No announcement yet.

Mine Detector

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Mine Detector

    I never had one of those "minesweeper" demolition sets as a kid.


    When I see them these days in person, they're usually non-functioning, have parts missing and/or they're broken.
    If they're in good condition and functional, they're priced way out of my comfort zone.
    I always wondered how they worked.


    I looked online to see how it worked... searching for descriptions or schematics and the like; I didn't find much.

    Then I ran across this little kit online... a "metal detector."
    Click image for larger version

Name:	Mine1.jpg
Views:	1
Size:	103.5 KB
ID:	6023
    It was tiny. Ran off a 9v battery. Hmm... it might work for Joe!
    I forget what I paid. $9? $14? I forget. But it looked cool, so I thought I'd try it. The kit was easy to assemble (maybe 15 minutes, max), and I tested it out. It worked great!

    When you get the coil near metal, the LED lights up. There is a provision for a little buzzer on the board, but it wasn't included. I can always add it later if I feel like it. IMHO the red LED light is fine.
    I built it just like the picture you see on the box above.

    But that wasn't the right "form factor" for a Joe mine detector.
    So I added a 4-wire extension cable between the circuit board and the pickup inductor.
    The length of the cable was carefully chosen, because it was the only set of wires I had in my junk box.

    Click image for larger version

Name:	Mine2.jpg
Views:	1
Size:	131.2 KB
ID:	6024
    Now I needed to find a way to put it in a backpack.
    All of my soft backpack ideas didn't work out. Gutting a field radio wouldn't have given me quite enough room.
    So I opted for a little box; it's a plastic box that some .311 bullets came in.
    It was the size of a fat backpack, but would hold the circuit board and a 9v battery nicely.

    Click image for larger version

Name:	Mine3.jpg
Views:	1
Size:	86.8 KB
ID:	6025
    You can see I made the LED poke out the top of the backpack. The wire bundle exits the pack just behind Joe's right shoulder.
    I added a SPST power switch to the top.
    Not visible in the pic are the slots I cut to thread an elastic fabric for shoulder straps (like the field radio has).

    Although it wasn't finished yet, I sized it up on a Joe, and liked the size and look.
    I tested it out again after all of my modifications, and it still worked great (so I didn't goof anything up).

    Click image for larger version

Name:	Mine4.jpg
Views:	1
Size:	54.3 KB
ID:	6026
    Obviously I'm going to have to fabricate some kind of wand-sweepy-pizza-boix-on-a-stick for it.
    I found a thick straw that was a perfect length laying in front of Joe in the pic above.
    Figured I can thread the wires down through the straw and to the inductor.

    But before I do that, I need to figure out what kind of disk I'll put on the end of it to house the inductor.
    I may have to scratch-build something out of sheet plastic (a rare substance --- almost like Unobtanium!).
    Maybe I'll find something I can recycle. Anti-freeze container lid? Small mustard jar lid? I dunno. It has to be plastic, though.

    Click image for larger version

Name:	Mine5.jpg
Views:	2
Size:	45.2 KB
ID:	6027

    The mine detector is only held on Joe's back with a rubber band for now.
    I need to put together an elastic for shoulder straps, but this rubber band was fine for my mock-up and for testing my "proof of concept."


    The coolest thing is that this actually works -- and it works VERY WELL!
    I can bury "mines" in the sand out back and sweep the inductor over it, and the LED lights up brightly.
    I've tried it with fender washers and tin can lids. Both work pretty well.
    Maybe we'll use fender washers for anti-personnel mines and the tin can lids for anti-tank mines (modern openers cut the lid off without sharp edges, so they're kid friendly).

    It's not finished, but all that is left is the fiddling (backpack straps and finishing the "sweepy pizza box on a stick" cosmetics).

    Then I'll give it a coat of flat Olive Drab paint and declare victory!

    - ATC






  • #2

    One more angle of the prototype:

    Click image for larger version  Name:	Mine6.jpg Views:	2 Size:	37.6 KB ID:	6032

    Here's the pizza stick I still need to fabricate:

    Click image for larger version  Name:	mineguy.jpg Views:	1 Size:	45.3 KB ID:	6033

    And here is an AN/PRS-1 from late WWII:

    Click image for larger version

Name:	an-prs-1.jpg
Views:	1
Size:	70.9 KB
ID:	6034
    It looks like it has a straight inductor rather than a pizza shaped one.
    Hmm... maybe I'll go that route instead.
    It'd be easier to disguise my inductor as a can than a flat pizza!
    :-)
    - ATC
    Last edited by ATC; 05-05-2023, 08:54 PM.

    Comment

    • #3

      None of mine work.
      - Scott
      PH and Proud
      Bulletmann - Hyatta
      See photos of my collection on my Pinterest Page https://www.pinterest.com/scottbeckmann/gi-joe/

      Comment

      • #4

        Looking good so far. I never had a mine detector, but I would love to get my hands on one.
        The Joe Collecting "Geek".
        Visit my online art store for some cool art prints:
        www.etsy.com/shop/geekdragonart
        Also follow me on Twitch for some video game goodness at:
        www.twitch.tv/miketheretrogamer
        Want to see my collection? Check out my Instagram:
        www.instagram.com/miketheretrogamer
        Want to see my new art? Check out:
        www.instagram.com/geekdragonart

        Comment

        • #5

          As near as I can tell, the original mine detector was just a flashlight. There were prongs on the sweeper, and when you touched the prongs to the metal "mine" it would complete the simple circuit to make the little light come on. Incredibly primitive, but I guess transistors weren't a big thing yet when the Joe mine detector came on the market. It was LONG before integrated circuits (ICs) were a thing, My mine detector just uses 3 transistors and a couple of scramble-wound coils to light an LED... and it's a REAL metal detector, not just a flashlight. I think it's pretty cool. I'm scrounging up options for the sweepy pizza box part. No luck yet, but I'm sure something will present itself sooner or later. :-)
          - ATC

          Comment

          Working...
          X
          Back to Top