Signal Disappearing.

Hi Guys, yesterday I was out and a strange thing happened to me, maybe because I do not have enough experience, perhaps happens more often than I thik.
I was using my 4500 with the 14 "x 9 " NFA, when I heard a very weak signal through the headphone, so as I always do, I scraped two or three inches of top soil, I tried again and the signal grew stronger, so I started to dig, every now and then try again with the metal detector and the signal was getting stronger, I tried even with the probe (Coiltek), the signal was coming from the center of the hole in the meantime was about 15 inches.
I continued to dig for another 10 inches and all of a sudden the signal disappeared, so I thought that the target had to be out of the hole, I tried and tried in all directions but no signal, was gone.
Now I wonder if anyone has had the same experience and how it can happen that a time signal is very strong there and the next moment there is no there any more. Thank you.
Cheers
Goldquest

Hi Goldquest,
First a question; do you have a magnet mounted on your pick?
I had the exact same problem a couple of weeks back, could not find the target anywhere, spent ages looking for it.
After a while I remembered the magnet, and there was the target, a 12mm nut and part of a bolt, I don't think I will get caught again.
Good luck, AUoptimist.

AUoptimist wrote:Hi Goldquest,
First a question; do you have a magnet mounted on your pick?
I had the exact same problem a couple of weeks back, could not find the target anywhere, spent ages looking for it.
After a while I remembered the magnet, and there was the target, a 12mm nut and part of a bolt, I don't think I will get caught again.
Good luck, AUoptimist.

Hi AUoptimist, yes I do have a magnet on my pick, I will check next time, it will save me a lot of digging.
Cheers
Goldquest

Sometimes a ball of clay can be highly mineralised compared to the ground around it and will give a positive response.When you dig it out the signal disapears as the clay is broken up.Often you notice the target seems to be shifting sideways as you are digging it.

Hi
Yes it happens on my place and it turns out when you dig up a hot rock it breaks up and the single breaks up with it
Regards Neale

G'day goldquest

I think you have been a victim of ground noise (false signal). A genuine target that is very faint from the surface like you said, by the time you have dug down 15" it should be really screaming on the 4500 with the 14 "x 9 " NFA and then after another 10" of digging you should have been nearly able to see it if it was a real metal target.

Try this next time it happens or you think it is starting to happen. Re ground balance the detector "correctly" on the dirt you have removed from the hole, (you may need to spread the dirt out a little bit flat to do it) when you have a good ground balance re check the target in the hole. If it is still there as strong as it was dig a bit more and repeat the process.

Mostly if it is just ground noise or a bunch of miniralized soil etc the signal will get much weaker if not nearly disapper altogether. If this is the case you can be confident that it is not a metal target.

Ground balance is one of the most important things you can do or not do correctly.

cheers dave

davsgold wrote:G'day goldquest

I think you have been a victim of ground noise (false signal). A genuine target that is very faint from the surface like you said, by the time you have dug down 15" it should be really screaming on the 4500 with the 14 "x 9 " NFA and then after another 10" of digging you should have been nearly able to see it if it was a real metal target.

Try this next time it happens or you think it is starting to happen. Re ground balance the detector "correctly" on the dirt you have removed from the hole, (you may need to spread the dirt out a little bit flat to do it) when you have a good ground balance re check the target in the hole. If it is still there as strong as it was dig a bit more and repeat the process.

Mostly if it is just ground noise or a bunch of miniralized soil etc the signal will get much weaker if not nearly disapper altogether. If this is the case you can be confident that it is not a metal target.

Ground balance is one of the most important things you can do or not do correctly.

cheers dave

Thank you Dave for the explanation, next time I will do as you told me, propably will save me a lot of diggings.
cheers
Goldquest

Hi Goldquest,
Am assuming you were searching with the machine in Enhance?
If not, next time try switching to enhance and if it is ground noise it will probably disappear.
As already mentioned ground noise signal usually shifts as you deepen the hole. Try approaching the hole from different directions.

Cheers
Peter

I have had that happen and its turned out to be an old cigarette packet.
Looses its signal when unearthed and broken up.Starts off good.

Alan

I've had it happen to me, faint signal, pinpoint from different directions, start digging, still there keep digging, getting louder, then gone, detect all over the dirt I just removed and nothing, Throw the hands in the air in frustration, fill the hole back in and the signal is back? Came back to this spot at the end of the day and finally revealed a small pin!
When I detected the dirt outside the hole the first time the pin must have been standing on it's end? Wish I never found it in the first place!
The good the bad and the ugly.
Cheers~Chris.

Hi Goldquest
I,m currently using the same setup and have experienced the same thing.The cause of the initial signal was due to the ground balance already being out and not an actual target even though it appears as one.You have likely wondered onto an area of hot ground.As you dig it seems even louder until the offending section of ground is removed or the detector is ground balanced to it.

kingfish wrote:Hi Goldquest
I,m currently using the same setup and have experienced the same thing.The cause of the initial signal was due to the ground balance already being out and not an actual target even though it appears as one.You have likely wondered onto an area of hot ground.As you dig it seems even louder until the offending section of ground is removed or the detector is ground balanced to it.

Thank you kingfish, you're right 100% because it happen again in the same area.
Cheers
Goldquest

Gday

A few times over the years I had dug a definate solid sounding signal only to have it dissappear completely , this is most annoying and frustrating when it happens as you start to think things like maybe you hit it with the pick and its shot away somewhere, and you start detecting around the place and wondering where it got to.

Anyway a couple of trips back I dug a good solid signal on getting the signal out of the hole and into the heap it started to break up, when I scraped the heap flat to better pinpoint it and then ran the coil over it was gone, I ran the coil this way and that but nada! not a squeak.

So now I was determined to work out what this was, put the detector on the ground and got on to the hands and knees for a closer inspection of the dirt, and there it was, tiny fragments of foil, very old and very nearly dust, my guess is that when the foil was in the ground it was probably in a ball and when disturbed and scraped over it just fell apart and crumbled away thereby not leaving enough mass to generate a signal from the detector.

It could have very well been the foil lining out of a cigarette packet, as ealier suggested, as they have been about for some years, I doubt it would have been ali foil as that is thicker and I think a more recent invention, but also ali foil when burnt in a fire crumbles as well so who knows, but anyway this particular mystery was solved, and after seeing that I would have to conclude that this might have been the same signal source that tricked me on other occasions as well.

Its not uncommon to dig hot little pockets of dirt out and then the signal dissappears also but most often than not the signal is iffy from the start and not quite so solid and definate, also you can get this from ant nests and carbon particles, decomposed charcoal, as well, and when dug out and broken up the signal is gone.

cheers

stayyerAU

G'day Ladies/Gents.

Apart from what StayyerAU has mentioned,I believe that both the concentrated halo surrounding the target,as well as the targets density play a role as to why that strong sounding target signal in the ground,upon being dug out,brought to the surface and dispersed,tends to fade out upon dispersion,to the point where the target can barely or no longer be heard. Picture a mass of concentrated iron or magnetic ironstone particles,gathered together in a clump or cluster,which tend to give off a strong and positive response to the coil when in the ground,but when dispersed and spread out on the surface,lose signal strength.
Aluminum foil,such as that from the top of a cigarette pack,although having very little density in terms of weight,when left on or near the surface flat and unscrunched gives a good broad signal(due to its large surface area),yet when the same piece of foil is scrunched and rolled into a ball or has weathered and dispersed in that one spot over time,can barely be heard when swung over by the detector coil(due to its lighter density and smaller surface area).
In your case Goldquest,I'm stunned.I just cant see how a "positive" target sound can keep getting stronger as you get closer to the target and then all of a sudden disappear.Normally mineralized target responses stay pretty much constant in signal strength until removed from there resting place and dispersed.

Cheers kon61.

Hi just been reading about disapeering signals. We had this happen numerous times in WA. in the end got so frustrated that on one hole we had dug I had a leek in it and then swung the detector over it again, signal gone, we then always tipped a bit of water in hole if signal got no better when digging up signal. phantom signals we called them. and all in hard virgin ground. Most times ground was a lighter colour chalky but very hard ground. the crowbar would just bounce of it.
Cheers travelergold

kon61 wrote: G'day Ladies/Gents.

Apart from what StayyerAU has mentioned,I believe that both the concentrated halo surrounding the target,as well as the targets density play a role as to why that strong sounding target signal in the ground,upon being dug out,brought to the surface and dispersed,tends to fade out upon dispersion,to the point where the target can barely or no longer be heard. Picture a mass of concentrated iron or magnetic ironstone particles,gathered together in a clump or cluster,which tend to give off a strong and positive response to the coil when in the ground,but when dispersed and spread out on the surface,lose signal strength.
Aluminum foil,such as that from the top of a cigarette pack,although having very little density in terms of weight,when left on or near the surface flat and unscrunched gives a good broad signal(due to its large surface area),yet when the same piece of foil is scrunched and rolled into a ball or has weathered and dispersed in that one spot over time,can barely be heard when swung over by the detector coil(due to its lighter density and smaller surface area).
In your case Goldquest,I'm stunned.I just cant see how a "positive" target sound can keep getting stronger as you get closer to the target and then all of a sudden disappear.Normally mineralized target responses stay pretty much constant in signal strength until removed from there resting place and dispersed.

Cheers kon61.

That is why I am asking the expert for some answer.

G'day Guys,

When I get an iffy signal, that does sound like a solid target, I will dig a few inches out and then swing the coil over the hole at the original ground level. If the signal is still as strong as it was originally it is most likely a valid target, if it has weakened it is most likely a ground noise. Try and balance your detector on the dirt you have removed from the hole and then test the hole again.

Cheers Mick