Metal Detectors - Find Junk or Treasure?

[Web Monkey]

I've played with a couple of UW metal detectors, but gave up because they were detecting every piece of junk hardware (nails, screws, beer cans, etc.) I came across, and I ran out of patience digging everything up.

I know this sounds bizzare, but are there any that will discriminate based on shape (rings and watches) or metal (gold/silver/etc. but not iron or aluminum)?

Is this a pipe dream, or actual technology?

Terry

 

[RadRob]

I had a White's detector and it could be "tuned" to only signal on items you are looking for. It wouldn't give a false signal on bottle caps or tabs. Mine actually told you on the display what it was that was beneath the surface. How it knew, I don't know. But I never proved it wrong. For as much as I paid for that dang thing (over $2000) I expected it to dig up the item for me. But I never figured out how to get it to do that.

Out of curiosity, what brand were you using? Top end, middle, or low end detector?

 

[cummings66]

I've got a Whites as well, but it works by detecting the type of metal and allows you to discriminate against junk. I rarely use it because most of what it finds is junk to me anyhow.

Note, mine is not for diving and is waterproof only to a limited amount so I can't get the entire thing under water. Probably good to 3 or 4 feet only.

 

[Web Monkey]

Sorry, I don't know what brand it was. I borrowed it to play with it for a while.

Terry

I had a White's detector and it could be "tuned" to only signal on items you are looking for. It wouldn't give a false signal on bottle caps or tabs. Mine actually told you on the display what it was that was beneath the surface. How it knew, I don't know. But I never proved it wrong. For as much as I paid for that dang thing (over $2000) I expected it to dig up the item for me. But I never figured out how to get it to do that.

Out of curiosity, what brand were you using? Top end, middle, or low end detector?

 

[fire_diver]

I've played with a couple of UW metal detectors, but gave up because they were detecting every piece of junk hardware (nails, screws, beer cans, etc.) I came across, and I ran out of patience digging everything up.

I know this sounds bizzare, but are there any that will discriminate based on shape (rings and watches) or metal (gold/silver/etc. but not iron or aluminum)?

Is this a pipe dream, or actual technology?

Terry

There are two basic types of detectors in use today. One is a VLF (very low frequency) and the other is a PI (pulse induction). Each is designed for different environments.

The VLF machines (some are single freqs, some use multiple freqs) work best on dry ground or fresh water. They can discriminate targets based on the type of metal (conductivity), and some machines can show you a size range the target falls into. ALthough this latter feature isn't really needed. You can tell target size by the 'size' of the signal when you pionpoint it. VLF machines arent very good in the salt water environ becuase the salt-water is a conductor and reduces the performance of the machine. The multi-freq units (like the Minelab Excaliber) can handle the saltwater better than the single freq units. You pretty much get what you pay for with these, so a good machine aint cheap!

Then you have the PI units. These machines suffer no interference from conductive salts, and therefor have GREAT depth capability. Their drawback is that they can not discriminate the type of target underneath. The cost base on these is more based on the manufacturer or the depth capability. None of them are cheap, but they dont get as expensive at some of the land units.

FD

 

[metaldector]

I have an Excalibur which can discriminate different metals. I can dial out ferrous materials, but I don't. A beer can sounds exactly like gold. I've dug up a beer can only to find better stuff underneath!
My buddie got a solid ferrous hit, and uncovered a conch shell fused to a piece of iron about 3" long, but attached to that was a beautiful silver piece of eight! A great looking coin minted in 1714. It hadn't thinned or oxidized. We figured the iron was a catalist and kept the coin perfect. I actually have a number of nails dating from 1700. What's junk to one is treasure to me.

 

[Web Monkey]

Great explanation! Thanks!

Th UW metal detectors I can rent are apparently not the kind that can avoid the beer cans and broken screws.

If I wanted to buy a good UW detector, is it possible to find enough cool stuff to recover the cost of the detector?

Terry

There are two basic types of detectors in use today. One is a VLF (very low frequency) and the other is a PI (pulse induction). Each is designed for different environments.

The VLF machines (some are single freqs, some use multiple freqs) work best on dry ground or fresh water. They can discriminate targets based on the type of metal (conductivity), and some machines can show you a size range the target falls into. ALthough this latter feature isn't really needed. You can tell target size by the 'size' of the signal when you pionpoint it. VLF machines arent very good in the salt water environ becuase the salt-water is a conductor and reduces the performance of the machine. The multi-freq units (like the Minelab Excaliber) can handle the saltwater better than the single freq units. You pretty much get what you pay for with these, so a good machine aint cheap!

Then you have the PI units. These machines suffer no interference from conductive salts, and therefor have GREAT depth capability. Their drawback is that they can not discriminate the type of target underneath. The cost base on these is more based on the manufacturer or the depth capability. None of them are cheap, but they dont get as expensive at some of the land units.

FD

 

[Web Monkey]

Not much chance of finding conch shells in the local lakes around here.

I was thinking more along the lines of rings and old coin lost by local boaters.

Terry

I have an Excalibur which can discriminate different metals. I can dial out ferrous materials, but I don't. A beer can sounds exactly like gold. I've dug up a beer can only to find better stuff underneath!
My buddie got a solid ferrous hit, and uncovered a conch shell fused to a piece of iron about 3" long, but attached to that was a beautiful silver piece of eight! A great looking coin minted in 1714. It hadn't thinned or oxidized. We figured the iron was a catalist and kept the coin perfect. I actually have a number of nails dating from 1700. What's junk to one is treasure to me.

 

[phoneman]

I have a fisher cz20 that is not cheap but is very tough and easy to use. It detects every piece of trash on the beach but I have learned to dig on everything. One of the first good finds I had was what looked like a piece of coqina rock that the dectector indicated was iron. When I got it home and broke it open there was a coin in it. It turned out to be a Conneticut Copper one of the first official coins minted by our government! I have found an area on the beach that contains a wreck from around 1920 that is heavily worked over by md'ers who don't dig anything thats not gold or silver. You might want to check out the Treasurenet.com forums for more advice on buying metal detectors.

 

[scubabear6]

Not much chance of finding conch shells in the local lakes around here.

I was thinking more along the lines of rings and old coin lost by local boaters.

Terry

I use a Tesoro Tiger Shark a great detector for finding small gold rings and chains in freshwater. Unforunatly yes a beer/soda can will sound like a good target sometimes but I would rather dig a 100 of these then to miss a gold ring or chain.