Annoying Phantom Signals and Roots

[rakoom2002]

Hello everyone. Im pretty new to metal detecting, I bought a Bounty Hunter Tracker IV and went out once and then came home and upgraded to a
Garrett Ace 250 because of the good reviews. I've been running into a couple super frustrating issues.

1. Phantom Signals: Ill be scanning and get a really good signal, keep going back and forth, moving different angles and directions and keep getting a solid signal, ill dig my plug and then scan the plug and nothing, scan the hole and surrounding area and nothing. A variation of the prior mentioned experience is when Ill do the same thing but scan the plug and itll ring up again with a solid signal, and then ill start tearing into the plug and partioning it. Ill then scan the pieces again and the signal disappears, rescan everything, the sod, the dirt, and the hole and the signal disappears. Its very odd and happens pretty often. I've tried turning down the sensitivity even and it still seems to happen fairly frequently.

2. Roots: Ive noticed that roots have set off the detector more than once for a solid coin signal (cant remember which one) but the signal is always super strong. Ill dig down and get into some super tough dirt because of thick roots. Ill go to the point where ill completely dig all around the roots and scan the root and itll continue to set off the detector. Its very odd. Im afraid to scan near trees now because ive been burnt by this so many times even though ive heard trees are good areas to scan because people sit against them when its nice out.

Anyways, I would greatly appreciate any light you guys could shed on this. Thank you!

 

Amazon Forum Fav 👍

Family Maps of Hinds County, Mississippi, Deluxe Edition - Grab it through Amazon!

[taz42o]

You may have mineralized soil. Rub a good magnet in the soil and see if it pulls anything out.
Im not sure what to do about it as the 250 has fixed ground balance.



Mineralized soil is soil that contains stuff to which a metal detectors search coil reacts, that is not a buried target. There are two distinct types of mineralization stuff that is magnetic and stuff that is electrically conductive. Soil most often contains a mix of magnetic and electrically conductive material. The more mineralization there is in the soil, the more mineralized is the soil. Soil with a lot of mineralization is often called bad ground.

Mineralization material that is just magnetic always produces a VDI number near -95. Mineralization stuff that is just electrically conductive always produces a VDI number near 0. The grounds VDI number would range between about -95 and near 0 based on the relative mix of how much magnetic stuff versus electrically conductive stuff there is in the soil.

Soil that has a mix of magnetic and electrically conductive material in roughly equal proportions would have a VDI number reading roughly halfway between -95 and 0 (around VDI -47). The more magnetic stuff versus electrically conductive stuff there is in the ground, the closer the VDI reading will be to -95. The more electrically conductive stuff versus magnetic stuff there is in the soil, the closer the VDI reading will be to 0.

The grounds VDI number only gives an indication of the ratio of magnetic stuff in the soil versus the amount of electrically conductive stuff in the soil. The grounds VDI number does not indicate how much mineralization stuff is in the soil. A fifty-pound bucket of soil that contains 10 pounds of magnetic mineralization stuff and 1 pound of electrically conductive stuff would be very bad ground. The same bucket with 0.1 ounce of magnetic stuff and 0.01 ounce of electrically conductive stuff would not be bad ground. Both buckets of soil would have the same VDI number. Both buckets would have magnetic stuff in a 10:1 ratio to the electrically conductive stuff.
The grounds VDI number does not indicate how bad the ground is. It does not indicate how much mineralization stuff is in the ground. It only indicates the relative amount of magnetic versus electrically conductive stuff.

 

[Wyomingmedic]

I have been having some of this as I learn my new detector.

Do you have a pinpointer? If not, get one. It will DRASTICALLY help. Plugs and holes where you are getting a signal but cannot find the object are annoying. On a lot of mine, I found that I was simply missing the target. The pinpointer made all the difference with that.

WM

 

[TreasurePirate69]

There is a very common problem with iron objects creating a "halo" effect that can be picked up by your detector but then disappears when the ground is disturbed. Essentially, this happens when a metal detector is set up to discriminate out iron. The rust of the object leaches into the dirt around it which allows it to be detected when in non-iron mode. When you dig around the item this rusty halo is broken up causing it to disappear. The original iron object is technically still there but is now undetectable because the halo is gone and you are in a mode that discriminates out iron.

A possible "fix" is to switch to an all metal mode when this happens to see if the target magically appears again. If so, this tells you that the object was detectable for a short while in your discrimination mode but that when you started digging the object's attributes changed so that it was no longer detectable with discrimination on. This is a very common problem that may not seem that intuitive at first. People think of objects in the ground as being constant but they are not. There are many factors which can cause an object to no longer be detectable in your current settings (or even at any settings). That's the nature of metal detectors. Trying different settings (all-metal modes, higher/lower sensitivity, higher/lower discrimination, etc.) when an object disappears is a good step in trying to understand what has really happened.

Of course this is just one theory of what could be happening. There are many other causes as well including mineralization as mentioned above.

 

[OUTCOME1]

get a dd coil for your ace 250. it will help with soil conditions and better target sepration

 

[TreasurePirate69]

Just to follow up and present other common occurrences that can cause this, here are a few other examples. The point of these examples is to show that there are many factors which can be at play. Any time you disturb the ground or alter the orientation of the target you are changing the original parameters under which the target was detected.

1. Imagine a small, copper rivet (like you find on Levi's jeans) sitting on top of the ground. Your detector rings out with a solid hit. You dig a plug 4" deep and pull it out, setting it upside down on the ground (dirt side up). Your detector tells you there is nothing in the hole. You swing your detector over the plug and it gives you no signal. Why? Because by turning the plug over you just put 4" of dirt between your detector and the target. Being small, the target is no longer detectable at that depth. Simple? Yes. Intuitive? Not always. Especially when your detector is wrong and tells you the target was likely a penny buried 4" deep.

2. There is a piece of foil sitting close to the surface. Your detector is setup to discriminate out foil but this piece is just large enough and has a shape such that your detector fails to eliminate it. You go to dig a plug but you have done a poor job of pinpointing. Your digger slices through the foil cutting it into several pieces or crushing the shape so that it is no longer detectable. The foil is still there but your detector cannot detect it in it's current condition due to the new shape/size and your discrimination settings.

3. A small iron rivet has completely rusted into a pile of rust dust in the ground. However, this pile of dust is very compact and concentrated allowing your detector to detect it as if it was still whole. You go to dig it up and the surrounding soil crumbles causing the rust to break apart leaving nothing of any real consequence. As scattered rust the rivet is no longer detectable.

4. A large object is buried fairly deep in the ground. Your detector detects it so you dig a plug. Digging the plug results in changing the conditions under which the target was detectable. There is now a layer of air over the target where there used to be soil. Air and soil have different electromagnetic conductivities. Before, the signal was traveling through potentially several feet of unbroken soil. Now the signal is traveling through a combination of soil and air. If you had dug a hole such that your detector coil could fit down into it you would have been able to continue detecting the target. But having dug a small plug, your coil is still just as far from the target as before with a poorer conducting medium in between. Your detector may not be able to detect the original object now if the original signal had been right on the cusp of not being detectable.

I could go on and on. One thing I have noticed over the years is that if a signal disappears then it likely wasn't a very good target to begin with. If you change your detector to all metal mode and the target is still not there (and you've flipped your plug, etc.), it is usually best to just forget about it and chalk it up to being trash.

 

[Roger Mn.]

Maybe your shoes have metal in them and can be picked up a foot away from the coil.

 

[TreasurePirate69]

Maybe your shoes have metal in them and can be picked up a foot away from the coil.

I've had that happen to me. Except for me it was my bag of junk/trash that I had tied to my waist. It was filled with large aluminum cans which would set off my detector every time I swung it to my left side.

 

[Frankn]

OK, let me first explain that the higher up the line you go on a manufacturers units, the less of this problem you will see. The higher units have more 'electronic help' shall we say , built in.
Now here is what I suggest you do, pick an area of ground with no signal. Place a dime on the ground. Adjust your sensitivity so that it just picks up 6" above the dime. Now go and detect. Frank...

 

[rakoom2002]

Awesome. Thanks for all the replies everybody. Will take everyone suggestions in consideration and adjust accordingly. Just a few comments.

I do have a pin pointer but its the one from bounty hunter and it really sucks lol. I literally have to be about 1/4" - touching the object for it to go off. Im gonna get the garrett one.

Will look into dd coil. thanks.

I think treasure pirate is right, this seems to happen when im discriminating iron. I will definitely try switching to all metal mode if this happens again.

Good idea frank, will try it out.

Again, thank you everybody for your input. Really appreciate it.