Metal Detecting 101 -- Got Questions?
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245 posts in this topic

Hey all!


A few of us got off on a tangent over on the World Coins Board about Metal Detecting, and instead of continuing to roll off-topic over there, I thought I would start a thread here on the Tangents board. The place across the street has a dedicated forum to the hobby of Metal Detecting, and we don't have that over here, yet, so this seems to be the best place for it for now.


If you have any questions about Metal Detecting, Detectors, etc. feel free to fire away and I will do what I can to answer them.


I have 15 years of field work experience with Detectors in many different situations and locations, and I know there are a few others here that also like to "Swing the Coil" and are willing to share some knowledge with those that are interested.


Metal Detecting and Coin Collecting go hand in hand -- you won't find a slabbed Silver Eagle in your backyard unless you bury it first, but I have added some really nice specimens to my collection for nothing more than my time and the initial investment in the Detector. To date I estimate that I have found about $6000 in total finds since I started. I have sold off quite a bit, mostly Civil War artifacts, and converted that cash into coins from more traditional sources... it's all good.


So, to get things started I will offer a few of the most frequently asked questions I get asked about Metal Detecting:


Q. How much did your detector cost?

A. Personally I paid about $800 10 years ago for my current detector, it was the top of the line model at the time -- the Garrett GTA 1000. BUT -- you don't have to throw down almost a grand to get started. Just like computers, Metal Detectors have gotten better and cheaper over the past decade. There are quite a few brands on the market, and all have entry level detectors that are more than enough to find some really cool things deep down. I'm partial to Garretts, so I will recommend the ACE 150 or 250 if you are looking for an entry level machine to get started. You can find them on eBay for about $200 New, and a bit le$$ used. I would stay away from the Wal-Mart and Radio Shack detectors, they find metal, but they tend to be a bit squirrely as far as ground balancing and pinpointing -- go the extra few bucks and get a nicer one -- Garrett, Whites, Minelab, Fisher, and Tesoro are good ones in no particular order, except that I always put Garretts first.


Q. How long did it take you to start finding coins?

A. My first detector was a Fisher 1210 that I got used out of the newspaper for $50, not a great machine, but it was a solid entry level rig in the early 90's. I walked out of my back door, and within 5 mins I had found my first Wheatie -- a 1925 in about VG 8.


Q. Don't you dig a lot of junk? Bottle Caps, pull tabs and nails?

A. Sure did at first, but after some experience you learn to figure out what a good coin sound is and what junk sounds like. The newer Detectors have excellent discrimination capabilities that filter out the pop tabs and nails and graphic displays that will tell you what the target probably is and how deep you are going to have to dig. I have gotten so good at reading the display that I can tell you with about 90% accuracy if a target is a clad or silver before I dig it... and that is with a 10 year old detector!


Q. How deep can you find coins?

A. Depends on a lot of factors including soil type and how the coin is laying (flat or on edge). The deepest coin I have found was a Seated Half at about 10 inches. Generally, the bigger the coin, the deeper the detector will find it. Deepest Mercury Dime I have found was at about 8 inches. Buddy of mine found a small cannon ball at 26 inches. Again, my detector is a generation back, the newer ones claim to go deeper.


Q. Aren't the coins you dig all screwed up from being in the ground?

A. Some of them are, but I have pulled some AU coins too -- depends on how much it circulated before it was lost, soil conditions, and what the coin is made of. Fertilizers and certain kinds of soil eat copper coins... fast. Salt Water is also a killer to some types. This will make some of you nuts, but I use electrolysis to clean most of the heavily encrusted coins -- the same basic method that they use to "clean" coins found in shipwrecks. Yeah, it's not ideal... but as I said, some coins come out clean and don't require it, others just need a rinse under tap water and a bath in some denatured alcohol.


Q. Seems like a lot of work just to find some wheat pennies and mercury dimes, you ever find anything that made your heart stop?

A. Yes. A gold ring with a diamond worth $2k. It was inscribed and I tracked down the owner. She had lost it while at a local swimming spot and left contact info with the people that run the park. Her husband owned a bar at the time -- I didn't have to pay for drinks in there until they sold the bar a few years later. I don't think I downed $2k in beer, but I sure tried... burp!


Q. How do you find places to hunt?

A. I talk to older people. I read local history books and old newspapers. I tell everyone I know that I have a Detector and I'm not afraid to use it. Just about everyone on this planet over the age of 12 has a treasure story to tell. Sister lost a ring, Granpa died and used to bury stuff in the yard, Uncle has a Civil War battlefield or camp on their farm... it just goes on and on... I have more places to hunt than I have time to get to them, but I have the advantage of living in one of the original 13 Colonies -- your mileage may vary. Keep this in mind, though: Any place that had significant human activity before 1964 has silver in the dirt.


That should get the ball rolling, what else would you like to know?


Other Detectorists should feel free to chime in with comments or advice, that's what the boards are here for -- sharing info!

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I metal detect myself. I upgraded to a Garrett1500 a few months ago from a garret300. Big difference. I don't find alot with it. Not that it doesn't work. This thing will pinpoint a coin within an inch. very nice detector. I've gone to a couple city parks,I found probably $3 dollars worth of coins. The oldest is a 1919 wheatback. I love to detect just not too many places that I know of to go. As for junk, I really don't dig much up. I know there's alot of junk in the nickel ranges of these and I may be losing a few nickels to avoid it but I tried and dug so much junk that it really isn't worth it. I stick to the silver and copper. thumbsup2.gif

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Parks are fun to take the kids with you to do some light detecting and practice, but they tend to have been run over by other detectorists over the years and can be played out at times. Not to say you won't find anything, it is just the obvious place to go hunt, and more than likely someone else has been there... multiple somebodies in most cases.


I like to work private yards in the older parts of town, the "richer" the area, the better... they are almost always untouched, and where I find my best coins. (The aforementioned Seated Half comes to mind...) the trick is not screwing up someone's grass.


That can be done a number of ways:


Using a coin probe and a "popper" to extract the target does virtually no damage to most lawns, but you can really scratch a coin up if you don't do it right.


Personally, I cut a V shaped plug in the turf and fold it back on the "hinge" that is created on the open end of the V. If you keep the plug attached, the grass will be fine after you backfill the hole and tamp down the V. If the grass is really dry, I go back over the cuts with a garden hose or bottle of water (I keep 4 or 5 2-liter bottles in the car when I go hunting) to help the healing process along.


There are also "Plug" type diggers, but I find them to be too damaging on the grass we have here in South Carolina. Might work better in other areas, but Centipede is the grass of choice around here, and the V plug works best.


Leaving a bunch of brown circles in someone's yard is an excellent way to never be allowed on that spot again, and shunned by the neighbors after word gets around.. and it does. I have been turned away a few times because of someone else's carelessness, and I don't push the property owner, I just apologize for the prior digger's inconsideration or inexperience and move on... they usually stop me before I get to the car and say it's cool if I don't cause any damage.


People are curious about what might be in their yard -- I always show them what I have found and offer to give them whatever they want from the pile, if they let me take a picture of it first. Sometimes they take a coin or two for show and tell, most of the time they just see a pile of dirty coins and don't give a flip about them.

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Q. How deep can you find coins?

A. Depends on a lot of factors including soil type and how the coin is laying (flat or on edge). The deepest coin I have found was a Seated Half at about 10 inches. Generally, the bigger the coin, the deeper the detector will find it. Deepest Mercury Dime I have found was at about 8 inches. Buddy of mine found a small cannon ball at 26 inches. Again, my detector is a generation back, the newer ones claim to go deeper.


I'll just lurk on this thread for the next 6-8 weeks or so. We have about 24"+ of snow on the ground. After that I'll pick up a detector and let you know if I found any treasures.

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I knew gedis3, that as soon as you started talking about a V-plug and all that you have never dug in TX ground. This ground is so hard that I usually dig my finds out with a jackhammer. Of course if I can get a small hole started, a small stick of dynamite sometimes works better also. 27_laughing.gif

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I knew gedis3, that as soon as you started talking about a V-plug and all that you have never dug in TX ground. This ground is so hard that I usually dig my finds out with a jackhammer. Of course if I can get a small hole started, a small stick of dynamite sometimes works better also. 27_laughing.gif


lol! Oh, I have been me.. not in that famous Texas "Dirt" (it's really just bedrock with grass on it -- lol), but we have this red clay thing in some places in SC (you Georgia Peeps know what I'm talkin' about...) that is pretty much what they make bricks out of... and they don't have to do much to it to make it into bricks, if you get my drift.


Fortunately, most of the time when I run into hard ground like that, it doesn't have grass on top of it, and the old US Army entrenching tool comes out.. I have one of those suckers with the "Pick" spike on the back. If it is totally bricked in, I'll mark a target (those flags on a wire that they use to mark underground cables and such are great for this), pour some water on it, and continue my pattern -- then come back 10 or 15 mins later to dig.


If you do have grass on top of the hard stuff, I usually find the target laying right on top of the clay strata and under the topsoil, often a coin won't work it's way down into the hard stuff unless it gets really wet for a long period of time.

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I was escorted, by two security guards from a City run park because they said it was not allowed. I argued with them that what I was doing was a recreation and that is what parks are my doctor tells me I need to get out and exercise, but all they did was put their thumbs in their belts and flared their hips...oh, oh, Mr. Magnum.


If I would have had a cell phone on me, I would have called 911. When I got home, I was so frustrated, I called the City Parks Dept. and they assured me there was nothing on the books that said I could not metal detect in the city wide parks.


I gave them the name of the guards that threatened me...well, their pistolas convinced me to move along, and asked that they be informed...dang Mall Cops


Best place I found was a park where they have had 4th of July fireworks for decades. Everyone sits on the ground...coins fall out of pockets, blankets are shook out...yeah, lots of pop tops and whole soda those get 4" deep still puzzles me.


Nothing significant as of yet, pocket change, silver/clad a few rings, a gold necklace, spent bullet casings, charms, machine parts and a host of other junk.


I've probably spent more on batteries than what I could ever recover...then I got smart and got rechargable batteries. Good post...last time I was out was two weeks ago at the Sonic Drive in resturant outdoor volley ball court...$2.75 and a cheapo ring (sterling)

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Good idea to start this it felt wrong to be talking about it on somones post !!


A little note about replaceing turfs


If you are detecting on grassland/pasture remember to turn the turf upside down as grazing animals Cattle/sheep and the like will pick them out as soon as you turn your back.. as i found out in the early days .. Lets say the farmer was not a happychappy .. but he did find it funny waching me fill all the holes back in from his landrover.. insane.gif

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Something not mentioned about hole digging:


Have a little tarp or something of the like to place the dirt on. Makes it easier to replace.


Yep, I was all psyched up with my MD purchase. I made a nifty sifter and was ready to go. Guess that I got discouraged before I made any finds. As mentioned before, I did find a zinc cent and a CO2 cartridge and lots of nails. There is certainly a huge learning curve. What frustrated me the most was all of the erroneous readings the detector was giving me. I just thought a top of the line Garrett should be more accurate about the depth and denomination. It even did it in loose soil calling a nail a half dollar at X inches.

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'tis all in the set-up, EZ_E.


Different amounts of minerals in the soil, even the amount of moisture in the soil can require adjustments to the standard Garrett programs. I had similar problems when I first moved from the old "analog" Fisher to the Computerized Garrett.


I figured "Hey -- this thing is super duper, I can just run it wide open and it will tell me all I need to know with no need to use my own ears as another level of discrimination."


I was wrong. You gotta take the info on the screen and then add it to what you are hearing -- dig a few questionable signals to see what is what with the display, it might be reading high or low depending on soil conditions. Play with the depth and threshold a little, make sure you ground balance after you make adjustments.


With my Garrett, here is the best method I have found to lessen the amount of junk you dig:


If you find a possible target, keep sweeping over the target as you walk in a circle around it, if the display and the tone stay constant or "locked" as you circle it, it is probably what it says it is. If the tone changes as you go around, or the display starts showing different values, you probably have found an imposter.


If you still aren't sure, or it is good most of the way around the circle, switch to pinpoint mode. In PP mode, you want the peak of the signal to be strong and concentrated, the display and tone should drop off quickly as you slowly move it away from the target, in at least 4 directions.. make a cross over the target in pinpoint mode and listen carefully, if the signal drop is tight, fast and equal in all directions -- that's a good indication it is a coin, or at least some round metallic object. If it is a nail or a large piece of junk calling itself a coin, it will sound "longer" on one axis compared to another in pinpoint mode most of the time, or the depth indicator will show a different depth on one axis compared to another. The Garrett will almost "lock" on the target when it is a good one and you circle, it will sputter different tones and the indicator will jump around when it's not. When it is marginal, you have to consider where you are and what the other trash in the area sounds like.


I have not been out for about 3 weeks, and all this talk on the boards got me itchin', and it's 70 degrees here today -- so I hit my own yard with the kids for an hour. House was built in 1977, so there isn't much chance of anything major, so I really never searched the yard except for some ground balancing passes as I played with some of the programs.


Total take in one hour this afternoon:


1 Sardine Can -- 5 inches down. Was saying it was a penny at 2 inches -- jumped around a little as I went around, but it wasn't jumping too much, so I dug it.


1 Vienna Sausages Can -- 4 inches down. Same deal.


1 Dollop of Solder about the size and shape of my thumbnail -- registered as a nickel and was a solid signal. Some junk is just gonna fool you, ain't no way around it.


Those were the first 3 things me and the girls dug, pretty frustrating so far, oldest daughter (11) losing interest fast... starting to play with the cats. Younger daughter would dig in the yard all day long if I let her, even if we only found sardine cans.


So, I decided to play with the sensitivity a little -- cranked it down a few notches.


Next target, tight lock on penny, it was a... 1977 Cent!


Next, 1995 D Dime...


Then a 1979 Cent...


Next up, 2 Dimes next to each other -- was a freaky signal by the tone, but the display locked on dime and wouldn't let go, in pinpoint mode I deciphered that I had 2 targets.


The hits kept coming... Ended up with 1 Quarter, 4 Dimes and 3 Cents -- all moderns, but 68 cents is 68 cents... gets me a third of a gallon of gas, give or take, not bad for an hour in the yard spending time with the kids.


After I had cranked the sensitivity (the GTA1000 calls it "depth") down a mere 3 notches, the *spoon* targets went away as if by magic, and only coins were dug from that point on. That small adjustment was all it took to get the Garrett to calm down a little and avoid the junk. It was still there, and I saw it showing up on the display, but it was registering in the iron and foil range where it belongs, not up in the cents and nickels notches, which might cause me to dig it up and get cheesed.

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I'll just lurk on this thread for the next 6-8 weeks or so. We have about 24"+ of snow on the ground. After that I'll pick up a detector and let you know if I found any treasures.


I'll be watching and waiting -- your property has TONS of potential for good finds, I'm sure you will find something that will be worth the effort, probably lots of somethings.


Sounds like you have the research/history bug already too, which is great for passing time when the ground is frozen and you can't dig. Spend the winter researching and scoping out potential spots, then hit the ground running after the spring thaw!


20% or so of Metal Detecting is finding the spots, if you can do that part when there is no way to dig, it leaves you more time to hit the field when you can.


See if there is a Metal Detecting club in your area. There isn't one where I live, so I "Lone Wolf" it most of the time -- but finding a buddy to show you the ropes, and maybe even lend you a detector to try out, might make the learning curve a bit less steep. Also some good Metal Detecting magazines on the market -- look for "Western and Eastern Treasures" and "Lost Treasure" at the newsstand... they are chocked with tips, and seeing other people's finds will keep you fired up.

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. If it is a nail or a large piece of junk calling itself a coin, it will sound "longer" on one axis compared to another in pinpoint mode most of the time, or the depth indicator will show a different depth on one axis compared to another. The Garrett will almost "lock" on the target when it is a good one and you circle, it will sputter different tones and the indicator will jump around when it's not.


Yep, that sums up my experience pretty well. blush.gif


And.......70 degrees?! This is a picture I just took outside. About 4" of snow today.




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Yep, that sums up my experience pretty well. blush.gif


And.......70 degrees?! This is a picture I just took outside. About 4" of snow today.


Snow? What the heck is that? Is that some kind of cold flaky rain? I had heard stories about it... thought they were just legends... insane.gif


Freakin' azealeas and daffodils are blooming here... time for the old allergy thing to get rollin'...


HUZZZAH! Spring is near! Hand me the Allegra D!


Remember -- March 2nd is Metal Detectorist's Day -- all Metal Detectorists get up at sunrise and go out on the front porch naked, if they see their shadow it means six more weeks of research, if they don't -- early Wheat Pennies!


...and once you figure out what a nail sounds like, you have my permission to quit digging them. grin.gif

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Today's Metal Detecting 101 Topic: Beach Hunting!


What?!?!?!?! Beach Hunting? Are you insane? It's 30 below zero!


I didn't say Ice Fishing (my personal terminology for those hard core NE Detectorists that go beach hunting year round...) I said Beach Hunting! If I can't wear shorts, I don't go. If you have to use an ice pick and a blow torch to get targets out of the sand, go to Florida, people... they got shipwrecks down there too -- Sheeesh!


Seriously -- They do it in the cold up there for one reason and one reason only -- the big winter storms that strip the beaches of sand and therefore uncover targets that would be too deep the rest of the year -- because the sand builds back up. I can understand that -- I don't condone it, but I understand it. I'm a Southern Boy raised by Ohio Yankees, and I likes my heat and humidity -- never had to shovel it out of my driveway, either.


So, back to Beach Hunting -- let's just imagine that the weather is warm and sunny...


There are 2 main categories of Beach Hunting -- Fresh Water (FW) and Salt Water (SW), and they require slightly different techniques. Sub categories of FW and SW include Dry Hunting and Wet Hunting. The difference between those is pretty obvious, isn't it?



Not all detectors are water proof -- most of the brand name detectors previously mentioned are water RESISTANT with a waterproof coil. This means you can get the coil wet without causing damage, but get ready to write a check if you manage to submerge the control box. There are some specialty detectors that you can dive with up to 30m, but they tend to be a bit pricey... the flip side to that is that they work on land too, so if you plan on doing both, spend the extra bucks up front instead of on repair costs.


Standard digging tools work on the beach, but since you are dealing with sand most of the time, there are some specialty tools that make the digging easier...


"Sifting Scoopers" are really handy and they come in both long and short handled versions. If you plan on working in the water, get a long one -- if you are staying on the beach, a shorty will do.


Don't forget the sunscreen, sunglasses and a hat. The really old guys like to wear black socks, Cuban barber shirts and pastel polyester shorts pulled up to their armpits, but I tend to stick with cargo shorts and a Hawaiian shirt with Teva sandals... no need to look like a total Dork -- you are already carrying a metal detector and wearing gigantic headphones, right?


Locations: Salt Water

Living in central South Carolina, I am only a short drive from the coast -- Charleston is 2 hours -- (no history there, horrible place to detect -- don't go there... ROFLMAO!) Myrtle Beach is 3 hours (Tourist City -- Jewelry, Jewelry, Jewelry) Savannah Ga. is about 3 hours (No history there either -- don't bother!)


Now, the cool thing about public ocean beaches is that they are public -- and very few have regulations against metal detecting. These are usually well marked, and the reasons vary as to why you aren't allowed to dig there... in my area it usually has to do with the fact that Sea Turtles have been using those beaches to lay eggs about 3000 years longer than we have been here, so they get "dibs". Most of the turtle spots are within State and National Parks, and you can't detect there anyway.




Also, Sea Oats -- those clumps of grassy looking things on the dunes, don't mess with those either... they keep the beach from moving to the middle of the ocean, and there are laws in most areas that protect them.


Turtle Nests and Sea Oats are up in the dune line, and unless you are working a beach with Civil War artifacts, (ever see the beach scenes in "Glory"? -- that was in the Charleston area) you won't be working that high up on the beach, because no one really hangs out there unless they are doing "The Nasty", and anything washing up from an offshore wreck probably won't make it over the dunes.


Setting up your detector to work properly on a salt water beach can be tricky at times -- some of them have salt water programs built in, but different kinds of sand and different amounts of salinity require different settings. It's one of those things you have to play with in the field for a while to get squared away. You will also have to readjust as you move further up the beach away from the wet sand and into the dry. Start at the low tide line and work your way up. No need to go over the dunes unless you want to find foil condom wrappers. (Now you old geezers know what "The Nasty" is, don't cha?)


Get some landmarks in your mind, or drag a piece of driftwood to mark a section of beach and work it back and forth... when on the beach, I dig almost everything -- for a couple of reasons. Gold jewelry, specifically necklaces, almost always show up as trash. Gold rings can also fall down in the lower Nickel, foil trash area of the display depending on size. The Sand is usually easy to dig, I have a sifter and the holes are easy to backfill... may as well dig it to be sure. Oh yeah, this is where I remind you to fill your holes... always.


Don't get frustrated with the trash -- there is nothing wrong with clearing the beach of pull tabs and other sharps -- might be your kids or grandkids that step on it. Grab all the glass fragments you see too -- same reason. Even if you don't find anything worthwhile, you will get a warm fuzzy feeling knowing you helped clean the beach a little and maybe prevented someone from cutting the bejesus out of their foot.


Do some reasearch to find the best beaches in your area. There are spots in Florida where Spanish Silver is found after storms, washed up from offshore shipwrecks. Tales are told that back in the 60's after a hurricane, people where picking up flat black rocks off the beach and skipping them back into the surf for fun -- turns out they were encrusted Pieces of Eight. D'OH!


Rehoboth Beach in Delaware is another hotspot -- there is a circa 1700's English Shipwreck offshore, and English coins from that era have been found after storms.


Outer Banks in North Carolina... Virginia Beach... the list goes on. Do a little reading to pinpoint the areas you need to work.


Locations: Fresh Water

Living in Columbia, SC I have another advantage. It gets hot here, almost unbearably so for those that weren't born into it, and people tend to hit the lakes and ponds to cool off... and they have been doing that for a really long time, since the area was settled in the early 1700's.


Swimming Holes abound, both public and private, and they are refreshed with a new load of Jewelry and Coins every summer. I happen to live about 10 minutes from the main swimming beach for Lake Murray, the biggest lake in the area, and it is packed from the first day of opening to the last day before school starts. Problem with that is, you can't detect efficiently with all those people laying around, so you gotta go when the weather is nasty and no one is out. Also helps if you know the park ranger -- sometimes they will let you in after the season is over if you don't go in the water. The ring I mentioned in the original post has done a lot to help me get in the gate after hours. I always check with the Park Attendant to see if they have any reports of lost jewelry before I start, and promise to return anything that I can if the owner can be contacted. They just remodeled this beach, added tons of sand and worked it over all winter while they were building a backup dam and new flood gates -- it's gonna be pretty dead for finds for a season or two.


Other places to look: Rivers, Ponds, Campground Ponds, even larger Creeks. Look for signs of human activity, most swimming spots have been in the same place for a long time... but don't be afraid to do a little research and find that long lost swimming hole from the 1950's... very productive and usually less trash than those currently in use. Don't forget to check over your head for remants of rope swings -- frayed rope or "Indian Burn" on large branches that overhang the water where the rope rubbed back and forth are really good signs.


You don't generally have the same setup problems on fresh water spots that you do with the salt water, but you do get more trash -- so you probably want to run a little less sensitivity until you figure out how much junk you are dealing with. Pull Tabs are the bane of your existence at swimming holes. I keep them all -- my kids donate them to the Ronald McDonald house as an ongoing Girl Scout project, where they get recycled and help sick kids -- another warm fuzzy offshoot of the Metal Detecing Hobby... treasure is where you find it!


That's all I have time to write up this morning (don't worry, I type at about 70 wpm -- about the speed you read it...)


As always, if you have any questions, don't hesitate.

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very interesting article George . keep it up - i do read some of the articles across the st. also, Ive done dectecting myself usually with son alot of the time during the summer. We hit schools around the area and he helps (of course i get to keep only the pennies) . Usually find quarters and dimes at the play grounds. real easy to kick the bark out of the way. Tried at a couple different sites along the Erie canal here in NY but no luck.


question - how come nickels give off tone sounds different than clad dimes and quarters even though they are 75/25 copper-nickel compostition. i know that the clads have a pure copper core and the nickels dont. Is it that reason.


Thanks Jeff

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question - how come nickels give off tone sounds different than clad dimes and quarters even though they are 75/25 copper-nickel compostition. i know that the clads have a pure copper core and the nickels dont. Is it that reason.


Thanks Jeff




Thanks for your kind comments, and your question. I'll try not to prattle on like an electronics geek (which I happen to be...) and explain how detectors (or detectorists if they don't have a computerized display) tell the difference... but you pretty much hit it on the head.


For the sake of discussion I will be referring to how VLF (very low frequency) detectors work as opposed to PI (pulse induction) detectors. Check the link at the end of this post if you want to know more about how both kinds of detectors work. Knowing how your machine works really helps you figure out what it is telling you, adding another level of target discrimination -- in your brain -- and some people insist this is the best type of discrimination, and it only comes with experience in the field digging both good and bad targets until you start to associate how your specific machine reacts... now on to the answer to your question:


The conductance and size of a target determine how much of a phase shift occurs as the target passes through the detector's electro-magnetic field, and the modern microprocessor based detector knows from it's programming that a given phase shift value (simplified here as: conductance + size = target value) is a given target by matching that value up with a known target value and gives you an indication on the display of what it "thinks" it is. Older and less expensive detectors convert the shift to audio output and maybe a strength meter, and you get to do the "processing" to determine what the target might be.


Since the detector signal passes right through the coin, clads with a copper core have a different reflected conductance value than those with an amalgamated composition like nickels, even though the total percentage of the different metal types may be the same. Don't forget size is also a big factor -- nickels are thicker and bigger than dimes, so they have a different size value. The detector "sees" these differences in the equation and reacts accordingly on the target indicator.


I'll take it one step further for you -- a silver dime will have a different target value than a clad dime based on composition alone -- since the size is a constant, it is only the difference in conductance between copper/nickel clad and 90% silver that causes the difference in total value. After you work an area for a while you can almost tell whether a dime or other coin is silver or clad before you dig it, but there are also other factors that have an effect on the signal, such as ground mineralization and depth, so it takes a good bit of experience in a specific location before you start to see and hear the subtle differences.


I hope that answers your question, if not -- feel free to post a follow up!


If you want to dig deeper into the subject, I recommend the website "How Metal Detectors Work" by Mark Rowan & William Lahr

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I have recently picked up metal detecting but I am having trouble researching places to detect. How would you go about doing this? Would you reccomend the library and historical society as a good starting spot? What types of documents should I be looking for? Thanks.

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What Dooly said is a VERY good tip -- I get my best clues on places to hunt from the older folks in a given area. They know everyone, and they know everything... start with family members if you have older ones local to you.


Old Local Newspapers can be found on microfilm at most main library branches for a given county or area. Librarians are also a good source of info -- tell them what you are doing, turn on the charm a little and see what happens. Look for stories about big community picnics or events. Check the days right around large holidays -- 4th of July is a Biggie -- people lay out in the park and watch the fireworks. When they get horizontal, stuff falls out of thier pockets.


Look for stories about hotels or the like burning down and are now forgotten -- most of them had outdoor recreation areas that are good to search.


Once you get in the mode of hunting for treasure leads, you will be amazed at the wild tangents your mind will take you. Ideally you want to find a spot that had a lot of people being very active -- preferably before 1964.


There are numerous books in and out of print. Kellyco ( has an extensive library available for purchase, and you can find them on eBay too.


The United States Treasure Atlas by Thomas P. Terry comes to mind immedately, it comes in multiple volumes that cover various states in each volume and can be purchased seperately... Volume 8 covers Rhode Island. (Also covers South Carolina -- the series is broken up alphabetically by state.) They list ghost town locations and details treasure legends for that state that have been accumulated over the years by the author from various sources. It has been in print for quite a long time, so I suspect that most of the places listed in it have been hit pretty hard by other hunters, but with detectors getting better and better all the time, going back over "played out" spots can still be very productive.


Here's a small sample of how the information is presented in the USTA, broken down by county in each state:



20. The pirate Captain Kidd reportedly buried $40,000 in gold on Patience Island.


22. After a winter storm in 1923, a local fisherman found a number of Spanish coins dated from the 1700's on Hope Island in Narragansett Bay. More may remain.


...and the listings continue on like that. Get a copy, you won't be disappointed, and it will give you ideas on where to hunt.


Check your local laws, always get permission from the land owner, and fill your holes -- Happy Hunting!

Edited by gedis3
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smile.gifCheers for that gedis3 smile.gif

Been out detecting this morning hear is what i found 893scratchchin-thumb.gif Can you ID them some are harder than others + there could be one from the US.. Can you spot it ? 893scratchchin-thumb.gif



Edited by dooly
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Dunno... can't spot it right off, put those crusty suckers in the electro-bath for a few hours and ask me again!


You UKers just kill me with that 1000+ year old silver laying in the dirt...


Sigh... back to digging wheat pennies... did find a 1934 Mercury yesterday tho...


I love finding the Mercs!

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hi.gif Yu are right it's not clear in the scan but the top Penny looks like a bungtown/contemp/forgery in the hand..


Do your copper/bronze coins come out as bad as the ones over here.


Date range of coins: Edward I/II1272-1327 to George VI 1941

I 27_laughing.giff it aint silver its bin fodder! 27_laughing.gif

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I suppose just like over there in the UK -- it depends on soil conditions as to how they look when they come out. I have the advantage of living in a fairly sandy-soil area, and those usually come out OK. If I'm in a farm field were fertilizer has been spread, they are usually pretty roughed up.


Thanks for showing us your finds!


Hopefully I'll get a little time this week to hit some older spots and have something to show off as well.

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Horse looks Celtic in origin... seems like I recall the "VEP" on some bronze Celtic coins in one of my treasure hunting magazines from a while back...


So, I'll slowly put my 2 wheat pennies on "Celtic Silver" and cross my fingers.

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Not bad !! i will give the "total" awnser tomorow as i must get some shuteye as its 00:30 over hear


Ps have you seen the coin i have listed on the recent finds in world coins you should have a go at ID on that one as well as you were good at this one


all the best dooly hi.gif

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