False signal

might be iron in the ground i find a lot of sand stone around here with iron in it drives me nuts
 

Did you "x-mark" the spot with your coil before digging ? Ie.: criss-cross in an x pattern, to make sure you weren't on the edge of a larger signal.

Do you have a pinpointer ?
 

no big roots not will cause false signals. that being said, your machine detects something metal. sometimes you can hear a big piece of metal very deep, but the detector says its only six or eight inches down. sometimes the machine will tell you a good target is there, but you have removed the ground that should occupy the target, only to find a rusty nail a few inches over. the key to eliminating these errors is to learn your machine and the pinpointing method of your machine. before you decide to dig the target it should be repeatable and solid. solid is hard to describe, but as you pinpoint the sound should be clear and definite. if it pinpoints all over the place it prolly a big target deep. if you hear a good signal, but it pinpoints several inches over, it prolly the old rusty nail. practice is the key. re-read the insrtuction book of your detector, this can be helpful, because when you read it the first time, you didnt have any experience. now that you have used it, now you understand better what the book is saying. be patient, go slow, think before you dig, have fun learning your machine. hope this helps david
 

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robgwv said:
I'm very new at this and have been dig'n in the woods,found shell cases,modern bullets,button (F2 guess ometer says zinc) But in several spots I get hits dig and dig But find nothing...Can big roots cause false signals???
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I ran into similar issues today. I got a solid hit and dug through roots and rocks for 20 minutes. The dang detector kept saying it was a 50 cent piece at 2 inches. I didnt have the proper tools to go real deep but i know exactly where to dig next time. A normal garden trowel just wasnt up to the task.
 

me too!!! solid high 90`s on the F75 just 2-3 inches down.......after elbow deep with a Garrett PP I gave up. Moved on and found a strong zinc signal and dug up six pennies!

ho well, the life of a digger.....
 

Large pieces of iron near by can give false signals too. Small bits on the surface can drive ya nuts too. I run my pin pointer over the spot first to make sure that I'm not picking up surface items.
 

I got some serious falsing today with my AT Pro. Never had an issue with my A250 but, figured out it was caused by power lines and a transformer that were about 15' above where I was swinging.

Jay
 

There is a "field-curving" effect caused by large, conductive objects that is nearly impossible to predict. That may or may not be your trouble. Basically, your machine keeps doing everything that it normally does, but the objects in the ground change the shape of the EM field around the coil. The detector (by far most detectors) average out the field state into a single value somewhere on the conductivity (discrimination) scale. That means that you could hit a small, near-surface target and some huge, deep object at the same time, and the big object will pull the field to the side, so you end up digging right between them. It's generally more of a relic-hunting problem, but can happen around any large, conductive object when there's a second signal around.
 

Redug where I had "false signal"....fired 22. bullets and BBs are hard to locate... Thanks for all the responces.
 

There are lots of situations that can cause this (many people have already given examples). The most common one that I've seen is when a rusty iron object (like a nail) is disturbed and you have your discrimination set to reject iron. When iron rusts in the ground it can produce a "halo" around the object in the soil that allows it to be detected despite having iron rejected through your discrimination setting. When you disturb the ground by digging, the halo is destroyed and the object seems to magically disappear. Technically it didn't. If you went to an all metal mode it would still be there. But if you stay in a discrimination mode then it isn't detected.

Of course, this is not the only way this phenomenon can happen. But this is a very common cause that is sometimes hard to identify in the field because it isn't necessarily intuitive. The next time this happens try switching to all metal mode to see if the signal can be detected again.

Also, if you don't have a pinpointer you would be doing yourself a big favor by getting one. The Garrett ProPointer is an excellent option.
 

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I have a pin pointer..But, plan to up grade to the garrett soon as i can
 

Jay In NewKen said:
I got some serious falsing today with my AT Pro. Never had an issue with my A250 but, figured out it was caused by power lines and a transformer that were about 15' above where I was swinging.

Jay
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Power lines or cell phones or any strong emf whatsoever cause chattering. Not falsing.
 

You can get some falsing, depending on the kind of interference. I've noticed that really thick gravel beds are a signal jungle for my MicroMax Silver because the ground is literally packed with millions of irregular crystals and zones of density. That kind of chatter can cause false signals, but you can usually tell that they are false because they are surrounded by an ocean of choppy signals and they are rarely repeatable. So, that's annoying, but not a real problem.

I've noticed that I can stand under a residential power line (less than 10 feet above me) with no ill effect to my metal detector. I can also get quite close to the power lines themselves (they are the highest off the ground for a lot of reasons). I can't get within 30 feet of a transformer, though (the kind that steps down line current to residential current). The AC fields around those things are huge. Get anywhere near a pole with a transformer on it and the effect on your metal detector will be far worse than being inside.
 

I was having some today, dig the hole and the signal would dissapear. I would still hear it pinpointing, but not detecting it. It ended up being a button, but I think that the machine can discriminate a target as the dirt around it moves.
 

olfacere said:
You can get some falsing, depending on the kind of interference. I've noticed that really thick gravel beds are a signal jungle for my MicroMax Silver because the ground is literally packed with millions of irregular crystals and zones of density. That kind of chatter can cause false signals, but you can usually tell that they are false because they are surrounded by an ocean of choppy signals and they are rarely repeatable. So, that's annoying, but not a real problem.

I've noticed that I can stand under a residential power line (less than 10 feet above me) with no ill effect to my metal detector. I can also get quite close to the power lines themselves (they are the highest off the ground for a lot of reasons). I can't get within 30 feet of a transformer, though (the kind that steps down line current to residential current). The AC fields around those things are huge. Get anywhere near a pole with a transformer on it and the effect on your metal detector will be far worse than being inside.
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The emf from power lines is usually smaller because they are essentially straight conductors. The transformers on the other hand are filled with coils that act just like the coil on your MD by transmitting emf signals. So what you are saying makes complete sense.
 

Good sensitive tecters chatter in houses and near power lines and other tecters and cell phones and stuff. Falsing is usually due to improper gb, too high sense, user inexperience, or any combination thereof.
 

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