The mystery of the disappearing coin

[BillF]

Went out yesterday. Picked up 6 silver dimes and 45 wheats plus a handful of assorted coins and tax tokens.
I would get a signal that said coin, flip the plug and then nothing. Sometimes if I stomped the plug flat it would be in the plug. Usually if I get a signal and open the hole and the signal goes away it means nail or bottle cap but these were good, coin sized signals so I scanned the hole with my pin pointer and sure enough there's a wheat in there. I've had this happen a couple times before but yesterday it happened quite a bit.
For you guys that are new to this, don't fill your hole back up and move on, check it. If its junk, then oh well, but don't leave a good coin behind.
Not certain why this is happening. The part that brothers me most is not getting a signal in my plug, especially after flipping it over. That puts the coin so much closer to the surface and my 705 isn't picking it up?

 

[7centsworth]

I have that happen a lot relic hunting.

 

[BillF]

Travis, I'm starting to wonder about my Digger coil. Went back tonight and found 5 more wheats but they were very scratchy and only good in one direction. Everything tonight was very strange.
Went to a large house with a large yard built in 1901. Searched for an hour and found...nothing! Well, not nothing. 5 stupid zincolns.
Might have to switch back to the 10.5. Starting to wish I had my stock coil back, I love the 10.5 but my torn rotator cuff hates it!

 

[Mark in S.E. IA]

Bill, I've had the same thing happen to me with the X505 and the 10.5 DD coil. Sometimes I've noticed it will do that when I pinpointed wrong and the target is off to the side of the hole.

If dealing with that pisses you off then do not buy a Etrac, it does it alot and most times it's on targets that are really deep.

Oh yea, congrat's on the silver and wheat's

pictures, pictures, lol

 

[BillF]

OK Mark. Here you go. There's 4 stacks of 10 of wheats with 5 loose ones at the top of the pic.
And its not really upsetting me as much as unnerving me. I don't want to miss anything. Good hunting spots are hard to come by here. As I was hunting here another gentleman showed up to hunt across the street.

 

[7centsworth]

What did those tokens come in at?

 

[7centsworth]

I think u got a stick coil I don't use. I would give you a great deal on it.

 

[BillF]

The tokens come in at 42, always makes me think I have a quarter. Normally silver dimes come in at 44, the ones this weekend all came in at 40 which just adds to the wierdness of the hunt and reminds me again not to rely on numbers alone for Id.
I'm not sure I can afford another coil so close to the holidays but what do you think you'd want for it?

 

[digginLa]

Was there anything different about the soil? I've had numbers change on me when I've found coins in the sand around playground equipment and even in the wood chips. Not sure about the other issues your having tho.

 

[BillF]

No, very nice dark soil, although GB numbers were 18-20 but that's pretty typical for my area.
I usually always run with tracking on so I don't have to worry about changing soil conditions.

Was there anything different about the soil? I've had numbers change on me when I've found coins in the sand around playground equipment and even in the wood chips. Not sure about the other issues your having tho.

 

[Old Longhair]

First, I want to say that it could be a bad coil, but also that not many have gone bad. So it's not something to rule out entirely.
Beyond that, I would consider it a prime opportunity to see if Tracking Offset could be of benefit. As I noted in my initial review of the "Digger" coil, ID tends to run about one segment higher than I was used to, and that remains true. I do tend to run a little offset, and I'm convinced that it enhances certain aspects. In my experience it can and has stabilized and improved ID and audio response to where good targets sound good, and trash sounds like trash.

 

[BillF]

I had every intention of doing just that but got caught up in all the signals and forgot.
I didn't quite realize I was having a bit of an issue until I went back and focused on iffy signals that turned out to be good. By then it was dark and rainy and I had enough.

 

[7centsworth]

I think u got a stick coil I don't use. I would give you a great deal on it.

That was suppose to say I think I got a stock coil I don't use.

 

[hotrod53]

Bill, are you using a pin pointer, I think that helps a great deal. I have also found over the years not just with my Minelab, but back when I used Tesoro, that a coin on edge is easy to miss. That coin laying flat could now very easily be laying on its edge once the plug is pulled and laid on the ground. I have had many cases of disappearing coins and I have missed that elusive second coin in the hole. I make it a point of scanning the hole again with my detector
and my pin pointer before I consider it an empty hole. You also have to consider that a good coin may mask the existence of a second coin and you never knew it was there without a second scan.

 

[Furious T]

I dont live in the USA, but I've sort of picked up that wheat cents are fairly old coins. Being older,it probably means that when you find one, it has been in the ground a long time. From what I've gleaned, they are made of copper, and are not clad. I've found, over time, that copper coins, when left undisturbed in the ground for a long time develop what some of us call a "halo effect". This is caused by metal from the coin leaching into the ground around it, and it will develop so long as the ground is not disturbed. The effect of this is that your detector signal senses a larger object than is actually there, and can give a good signal on a deep coin. When we dig a plug, we disturb the soil (in the ground as well as in the plug) and so a coin does not "look" the same to the detector as it did before the ground was disturbed. If the coin is deep, your detector may not pick it up if it is at the bottom (or deep in the side) of the hole. The same thing can happen if the coin is still in the plug, and the plug is a big one. The coin has lost its halo, and the detector cant "see" what it did before. This is where a pinpointer can help, because you can put it into the hole, whereas you may not be able to put the coil in the hole. Sometimes you may have to destroy your very carefully removed plug, and a pinpointer can help there too. HH BTW, this phenomenon occurs with many vlf detectors.

 

[Sevenpiece]

I have had the same problems listed above,every one of them with a 505, Safari, ETrac, and now with my 3030. Silver is tough sometimes, gold and nickels are even worse. I've seen a freshly buried Merc not id at all with a Etrac. Why you may ask ? your guess is as good as mine. Oh I must say I have over a 160 silver coins, unknown amount of silver jewelry and 6 gold rings this year, one gold ring found with my XTerra 505 15" WOT 3 khz.

 

[BillF]

As with most things in life, metal detecting is about learning and adapting. So many times I've had a signal disappear after digging a plug and just assumed it was an old nail or other price of iron that lost its "halo" when I disturbed it. Sure wish I would have spent more time scanning the hole with my pinpointer. Live and learn, I won't make that mistake again.

 

[Furious T]

One other things we can do when a signal "disappears" is to check around the hole, 12" - 24" in diameter in all directions...targets can come out of the hole in a multitude of ways e.g. stuck to our digger or with some small amount of dirt which can "fly" out when we are levering or generally extracting the main part of the dirt. Targets can fall off or go where we really dont expect them to go. It's all part of the fun. HH

 

[Dirty Nails]

Years ago, I don't remember what year but man was it dry in Tennessee. I caught myself several times digging that hard dirt and while prying with that saw tooth gator digger ,the dirt would pop loose and a coin or whatever would land 10 or 15 feet away. Sometimes when that plug suddenly breaks loose like that, the target will come out of the ground so fast that you can't see it.

Rickey

 

[BillF]

I always found the coins, they didn't get flipped out of the hole....they just disappeared. I had to use my pinpointer to find them,which opened my eyes to a problem I didn't know existed before. In the future, if I get a disappearing signal that i was certain was a coin I won't just assume that its old iron.