Learning Your Metal Detector Using a Coin Garden

The Coin Garden for Metal Detecting

The Coin Garden for Metal Detecting  (click for larger version to print)

Metal detecting takes practice and patience – and one of the most important things you need to do is learn what sounds your metal detector makes for different types of metals in the soil.  This recommended approach would be appropriate for most medium to high end detectors, including the Garrett AT-Pro that I currently recommend for beginners.

Nature is variable and metal detectors are not perfect.  They may occasionally say that a pull tab is a coin, and visa versa.  But statistically speaking, learning your “tones” will lead you to dig better targets, more consistently while leaving the junk in the ground.

I’d like to introduce one of the mainstay methods for learning a metal detector in the turf – The Coin Garden.  It takes a couple hours to set up but it can give you a consistent “classroom” for listening and learning your machine.  Don’t let the name “Coin Garden” fool you… you will also learn how to find jewelry and other items along the way – trust me!

What a Metal Detecting Coin Garden Can Teach You

  • The distinctive double-grunt of nails and fence wire.
  • The crisp, clear squeak of silver.
  • The crisp high-tone sound of copper.
  • The low, clean tone of gold and nickels
  • The scratchy sound of rusted pop tops
  • How similar gold and pull tabs sound.
  • How your detector may mistake a folded pull tab for a coin.
  • The different signals for different types of pennies.
  • How to pinpoint the target using the metal detector’s pinpoint mode.
  • How to determine depth of a target.
  • How differently your detector sounds on targets on the surface versus 6″ down.

Coin Garden Supplies 

  • your metal detector and (ideally) your pinpointer
  • headphones
  • a digging tool
  • An area of turf around 20′ x 20′ ideally with as few roots (tree or bush) as possible.  There should not be any pet containment fences nearby, and you should try not to put it directly under powerlines.   Also consider where your Cable TV, heating oil, phone lines, etc. are routed.  You don’t want to cut them making your garden!
  • A very small package of white or yellow plastic golf tees (bigger, longer ones if possible)
  • A fine tip sharpie
  • A small can of grass seed (optional)
  • 11 “targets”:
    • 1 Silver dime (pre-1965)
    • 1 Silver quarter (pre-1965)
    • 1 Nickel
    • 1 indian head penny (1859-1909)  (88-95% copper)
    • 1 wheatback penny (1909 – 1959) (95% copper)
    • 1 modern, zinc penny (1990+)
    • Pop top from a beer bottle (Ideally a rusty one.)
    • 2 pull tabs  (one folded over into a coin-shape, and one spread out lengthwise)
    • A small iron nail and a large iron nail (ideally rusty)
    • A small solid brass item no larger than a matchbox  (antique is best)

Everyone can benefit from a coin garden!

Everyone can benefit from a coin garden!

Steps to Create your Coin Garden:

  1. Choose a space, ideally not too close to trees, bushes or where a drive way used to be (roots and gravel make for tough digging)
  2. Mark the corners of your garden somehow.   Landscape flags are great, but ugly long term.  Bricks or brick-sized stones work great as long as the mower can clear them.
  3. Put your metal detector in “all metal” mode and completely clear the area of all targets (dig everything, however faint!) so that your garden starts clean.  Make absolutely sure that you have your discrimination OFF (Zero / All Metal Mode) and your sensitivity at around 3/4-4/5ths maximum.  If possible, it would be great if a more experienced metal detecting friend to clear the space as this step is essential.  Use your pinpointer everywhere.
  4. Recheck every hole and pile of dirt for signals before refilling.  Often, targets hide in the dirt clod!
  5. Divide the space into a rough grid, leaving distance between “spots” and the edge of the garden (see illustration)
  6. Sketch your empty garden on paper.
  7. Dig a 6″ deep hole in each spot – neatly piling the dirt next to the hole.
  8. Assign a hole number to each spot and add that number to the top of the golf tee and your paper sketch.
  9. Get your bag-o-targets and put one them flat in the bottom of each hole – and put this information on your sketch.  The order of the item from the list above is not important.
  10. Insert the appropriate, numbered golf tee into the center of spot – low enough to be clear of lawnmower but directly over the target.
  11. (Optional) Sprinkle grass seed throughout the garden – add water as needed.

You now have a “coin” garden, with a variety of targets buried at a typical 6″ depth, and the notes to help you remember what is where.

Using your Coin Garden

  1. Turn on and put your metal detector in coin mode, or choose settings as recommended for a beginner from the owner’s manual or online sources.
  2. Spend time on each target, noting how differently they sound.  Some detectors will have less sophistication here.
  3. Pay attention to:
    1. The frequency of the tone – high, med or low
    2. The “crispness” of the tone – is it “tight” or “sloppy”
    3. The differences between each type of target.
    4. The VDI number on your display (if applicable.)
  4. When to use the garden:
    1. While you’re learning (of course.)
    2. Before each hunt season
    3. Before each hunting day.
    4. Anytime you’re trying new settings (avoid too many changes.)
    5. When you get a new metal detector.
    6. When you’re teaching.

Troubleshooting

I can’t hear any targets or I can only hear the larger targets
Check that your detector is working for items on the surface.  If so, you may have your sensitivity too low.  Turn it up until the detector has “chatter” and then turn it down until it’s gone.

I can hear the silver coins but not the nickel
You probably have a discriminator setting that filters out low conductivity items.   Try putting your metal detector in “all metal” or “zero descrim” mode to make sure it can hear the targets.

Everything sounds the same – the nails, nickel and coins are identical.
You may accidentally have your metal detector in pinpoint mode.  Turn off pinpoint mode and try again.  This is VERY common mistake.
Your detector may not set up properly.  Please consult your owner’s’ manual and try to find a good beginner mode  (I cannot tell you how since there are so many detectors.)   Many times the best mode to start out in is “Coins.”  This should set your discriminator properly for the coin garden.

The metal detector is making lots of strange pops and clicks
You may need to change frequencies, ground balance, or reduce sensitivity.   You may also be near electrical interference, such as a pet-containment fence.

The metal detector is acting strange and inconsistent
You may need to ground balance – it may be automatic or require a small procedure – but proper ground balance for each location is critical.
You may accidentally have your metal detector in pinpoint mode.  Turn off pinpoint mode and try again.  This is VERY common mistake.

 I hear targets that are not under my golf tees
A new target may have been dropped into the garden.  Find it and remove it – it should be on the surface.  The other issue might be that the garden was insufficiently cleared out before starting.  You may have to sweep the non-teed areas of the garden again (not as easy now with your seeds in place.)

 

Good Luck, Happy Hunting!!!!

 

Scott