Prepping: Metal Detecting 101

In Saturday’s column I hinted that I would wade a little deeper into the idea of “hobbies that can make money” for you…and by the title, you ought to know where this one is going.

For the gold!

Bit of personal background:  When I lived in the PNW – and even when I was on my sailboat – I often carries a small 10-12″ plastic pan to do a “little sniping” for gold.

Problem up there is that most of the good places to pan are either a) already someone’s claim, b) owned by people who want nothing to do with miners, and even if you get through all that there is still c) environmental regulations.

A few times up into Canada I tried some “sniping” on the mainland side, but honestly, the best I ever saw were a few flecks of ‘color.’

Surely, there has to be a better way?

Then about five years ago when we were out looking for this & that, I happened to spy a used metal detector.  Put it into the storage shed – where I have a nearly unlimited supply of incomplete projects lined up – and didn’t think any more about it until a month or so back.

Then the “gold bug” bit – and bit hard.

I figure I could use a new hobby about now:  After living on a sailboat for more than 10-years, rebuilding a homestead in the wilds of East Texas, flying our own plane on transcons…oh, and marrying the most wonderful mate in the world…perfect ham radio collection, antenna farm, ideal (for my needs, anyway) shop…..anyway, what more can a fellow do?

To find the 40-pounds of gold stolen by outlaws back in 1852…yeah, that’d be the peach, huh?

In keeping with “economic reality” – which hobbies should conform to – my choices can down to a) building a “rat rod” or b) hauling out the metal detector.  It was a harder choice than you might think:  eBay is full of pricey rat-rods and I’m pretty sure I could build a tricked-out ride that would fetch a decent price and profit.

Except for one thing:  Suppose the market continues its nose-dive.  Do I want to be stuck with a 2-ton whale that eats gas and insurance?  Nope.

I didn’t know anything about detectors when  I picked up this one.  It’s an old Treasure Tracker, model DX-5000.  Set me back about $30-bucks.

After looking into detectors a bit, I figured there were three main types.

First are units like this one – which is a VLF (very low frequency) oscillator type.

The second class is more spendy – and use a process called “pulse induction” to detect metal and minerals.

The last class – and possibly the best – is the high-end multi-frequency detectors.

Theory or Operation

I’ll keep this simple.  They eat batteries and (sometimes) find useful bits of metal.  I’ve gotten exactly one penny with it so far…

Once I get the battery cover replacement cobbled-up…

The VFL models use an oscillator which uses (as part of its circuitry) an inductance  – a coil – that is swept over the ground.  The ground has a certain electrical property so when you “ground balance” the unit, and adjust the discriminator just right, any change in the field under the loop changes the electrical properties of the  circuit and the unit makes noice.  The general frequencies of most retail machines nowadays is in the 15-20 kilohertz range, but my old one looks like it’s down in the 6.5 kHz range.

VLF machines are inexpensive to make – only a few dollars worth of electronics… but the physical parts still cost money.

Pulse-Induction (Pi) machines are more graceful.  They generate pulses which drop into the ground and offer a change in the return which is also picked up by the search loop.    Think of this as a “baby EMP” and listening for a return…not quite, but a useful visualization of pulse induction systems.  These are your second level up in the pricing food chain.

Multi-Frequency machines are the top of the food chain units – and from here about all the further you could go would be a ground-penetrating radar – which I’m also noodling!

The MF machines are essentally two VLF machines, operating on different frequencies.  Maybe you have one operating down around 6 kHz and a second loop (hence, four-wire loops) may be using 18 kHz.  Using a comparator chip, and some not terribly complicated logic, the builders of such machines figure:

If the lower frequency circuit goes up in frequency, but the higher frequency unit only goes up by this proportion, not something else, then it’s likely (fill in the material; gold, copper, or another damn pull-tab!).

Now you’re talking real money.

ROI Considerations

So far, my “investment” in this hobby is the $30-bucks at a sale long ago.  Toss in some Gaffer tape, and a case of Amazon Best 9-volt batteries, and that could be it.

Except (you know me) is is nver enough!

So I picked up a unit from England called a Surf PI 1.2 and in a further epistle, I run you through radical design and re-forming the terrible form factor of most units.

This should get me into the area of super performance as there are a couple of sites on the new which do a fine job of walking people through how to build a Surf PI, but they aren’t as good when it comes to making something “Old Man Friendly.”  (Biting my tongue not to get deeper into the design part, but seriously, another morning for that…)

What’s the return on investment?  On $35 bucks who cares?  If you get a $5,000 machine, then you damn-sure better be retied AND be living in an area where there are lots of places people drop thing!  (Under bleachers after Little League games, I hear, works out sometimes….

The Historical Information Quest

My son has also taken an interest in treasure hunting.  Like me, he’s had a lot of serious adventures.  How can one base jump and not be an adrenaline junkie?

What has him fascinated is – because he does things like hike the Pacific Crest Trail (PCT) in modest slices, as time permits – ghost towns.

That’s what I’m talking about.  I fet out in some of the most wild country but you’ll find places that humans have been before.  That’s why i’m interested…plus if I could fine a place where there was some loot stashed from a bank robbery in distant history, well, that’d be fine too…”

Elaine and I have been slowly “circling” a couple of areas that our research into “America’s Lost Treasure” books have gotten us interested in.  One is a supposed stash of gold to the southeast of us an hour’s drive, or so.  The other is a hundred miles west/northwest of us.

The point is there are two ways to look at this hobby:

Approach 1:  Get a modest detector and then spend endless hours our in public parks, ball fields, playgrounds, beaches…anywhere there are people because people are always dropping things.

Your odds of getting “rich” this way are thin…but there are enough coins to be found that in an urban area, you might be able to keep up with battery consumption.  Then, it’s only a matter of time (though the Law of Large Numbers is at work) before you luck into something of real value.  it doesn’t take too many $400 rings to pay for the hobby…

Approach 2:  Use half your time in the hobby to get out and do some real detecting.  But, be more selective and careful about where you go.

Take the other 50-percent of your available time to study the hell out of local history.  Old battlefield and ghost towns are first-rate prospects and the odds are fair…if you dig deeply-enough into history books…that there will be a site, or several, that have never had a thorough detection plan applied.

Here, we can see how the results from the hobby “sort out.”  You may have the “fair weather amateur” OR you can go off the rails in the other direction, buried in topo maps, Google Earth shots zoomed in, and books from the dustty “State History” stacks of the regional library.  Many of these will never be digitized…because Librarians (like my older sister) have a very good sense of what the public wants and libraries all operate on a budget.

Between Google Books, SribD, some state-by-state Kindle books, and yes, even the old Louis L’ Amour books are useful because he actually went out and walked almost every inch covered in his books.

One last point:  If you’re fortunate, as we are, and have some old foundations or piles of rock around property that just “shouldn’t be there” then old foundation remnants like this one out in our South 16 become great afternoon projects to test your skills…

A special note to Santa and Mrs. Klaus:

Three units to think about in a variety of price ranges:

Under $140 try the Bounty Hunter Discovery 3300 Metal Detector.

If you’re in the $230 class maybe a Garrett ACE 250 Metal Detector with Submersible Search Coil Plus Headphones.

Up the food chain (and just down the block from the poor house)? Try the $18,365  Zxh 3D Imaging Detector Underground Metal Imager.  Small enough to fit in the boot of the Rolls….

Time to warm up the soldering iron, I have a Surf PI to complete…

Write when you get rich (or the buzzing sounds increase, lol)

author avatar
George Ure
Amazon Author Page: UrbanSurvival Bio:

23 thoughts on “Prepping: Metal Detecting 101”

  1. I have the Bounty Hunter. Mine does not eat batteries. I have recovered over $5 in coins which gives me a way to go for breakeven, but I have located items I dropped in the grass & arrows that sunk into the ground after a miss. Also, I have meet a bunch of grumpy people who complain when you dig that you are destroying the area & have been asked to leave even though I replace the dig so you don’t even notice it,

  2. Great Idea, great hobby, next thing you know you will be looking for ship wrecks and Grand Canyon gold. Any ideas there?

  3. I have a cheap one, bought it used off ebay some years back. I’ve used it to find some old poptops & a rusted can. I lent it out to find a lost ring and twice I’ve used it to find rebar property corner markers left by the surveyors many years ago.

    There was a fair amount of digging with that poptop!

  4. George, Since you have decided to be a swinger, it is only fitting that I dig up and send you a membership card. The club is the Treasure Trove Club. Dates are 1938 to 1988, when the founder, Raymond Dow, died. Your card was printed in the mid thirties.. Since we may time on our hands, I would suggest a Rutus Alter 71, Polish machine, which Mike Hare rated number 2 in the world. The Deus at number one because it has waterproof in rain… Since the ground is frozen in Ohio, I can always offer to loan you it.. Re, the club, most of us are long gone… The secret, is to dream, enjoy the outdoors, and not get greedy. Of course it is required you leave no holes or evidence of your passage.. Forgetting school yards, you can go to virtually any town of 10 K, buy breakfast, and gas within an hour or two, maybe find a good ring several times a month.. I use the Rutus to kook for Native American copper (museum donations). Last cent, found, 1801, worn, but the date fits with the settlers arriving in the early 1800’s, so a museum offering. Never found anything of value , but I have some nice pictures, and memories.

  5. Have seen a fellow who made his own device for panning gold. It looked like a small staircase that gyrated by means of an electric motor. Poured sand with water on top of the staircase, gyrations caused sand grains with larger stones to fall off the stairs. What ended up at the bottom of this staircase was black powder with gold flecks. Figured this deposit was taken for later processing. Suspected black powder was iron. Tried to talk to this fellow, but I could see he was not interested in any conversation. Could tell it was a homemade contraption, so don’t blame him not wanting to talk about it. Sure beats “panning” for gold the old fashion way. I am sure there are different home inventions that make panning an interesting and profitable hobby. If it is a successful hobby, no one writes about it. If it isn’t, they write a book hoping to strike gold that way.

  6. George, I noticed that the detector unit that you have seems to use two 9V batteries – probably in series. If so, you could easily rig a modern 18 or 20v battery from whatever line of tools you’re currently using. Li-ion would be best, and a couple of dropping diodes would match things if the voltage was a bit high. You could detect all day or until your back got tired. I’d do it except for the million other projects I have here.

    I am wondering how difficult it would be to detect a cast iron sewer pipe from the house to the septic. It’s iron from the house – I’m sure, but once it gets out into the yard all bets are off. I’m not sure how hard it would be to thread a transmitter into the pipe without getting it stuck somewhere, and cast iron would largely kill the signal. Passive detection would be best, from the top, but digging here is a chore and I’d rather be right first time. Depth is unknown – likely less than 4 feet.

  7. “Problem up there is that most of the good places to pan are either a) already someone’s claim, b) owned by people who want nothing to do with miners, and even if you get through all that there is still c) environmental regulations.”

    Years ago.. When I was very young..
    There was an old hermit.. And while camping on a family weekend getaway he told us kids a story of when he was a young man.. A bunch of bandits attacked a pay role wagon heading for a fort out west. They sent for help and he was one of them sent. They got into a skirmish and chased them to a spit near the campground. The bandits hid twenty thousand dollars in twenty dollar gold pieces. He hunted his whole life there trying to find it.
    Years later I would go out while the kids would be playing and searched myself.
    Obviously I didn’t find anything ..
    My old boss would get upset at my reading and someone had passed away the family threw the library bosses tossed a book at me saying why don’t you read this one..home fires burning…every couple of pages there was a fifty..those that went through the collapse of the thirties would put gold and silver coins in mason jars and bury them.
    Also panning for gold..sweep off the sidewalk outside jewelry stores then pan that.

  8. i have a cheap old one i use on my 7 acres,Never found the 1 carat engagement ring the bride to be threw into the woods during a heated argument.Have found my own wedding ring twice,I have recovered arrows too that at 6 bucks a pop add up find was 100s of bullet brass,m1 garand and m1 carbine.someone brought a few things home after the war.what is really stunning is how deep a coin from the 1980s can be a foot or more is a long way to sink in 30 something years,

  9. There is a trunk of treasure somewhere hidden in New Mexico or Colorado. A guy wrote a book about it giving hints. Look it up. 2 people have passed away while looking for it, maybe more. That would be quite an adventure seeing you and Elaine and your son putting your noggins together locating that trunk of treasure. You could combine it with a 2 week seekers trip made up of Urban Survival participants. That would be an awesome array of talent. I volunteer to be chief bottle washer and organizer of base camp.

  10. My best year was 69 precious metal finds coins rings Tokens of stores bars pool halls merchantile paid the best 400.00 for three tokens. Paid for 1600.00 machine in three years. People get nuts about gold creeks have been worked for 150 years so have to go where they couldn’t. Got 9 oz this year Pretty it is. A claim track hoe dump truck wash plant

  11. I live near/on water beaches etc I have often thought of coupling psychic abilities with well as historical research It’s an interesting idea. We should put together a club as someone else mentioned. I am really interested in this pursuit

  12. Hey bud,took a little hiatus. Metal detecting kicks azz. U need a discriminator n depth finder. Got a mid line bounty hunter (350) years ago. Some hints. Unknown or by a whim,start with the oldest lookin tree n move outward. Now digging a hole they can’t bitch about, get a stout 10-12 inch soils knife. After u x the target out,make cone. Remove grass,put dirt into Frisbee, continue. They dont bitch at me for respecting there dirt anymore.

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