Lost Signal

[Gravity]

Hey guy's was hoping someone could help with this question,

Was in the G.T last weekend and had a great low signal from the Z, after about a foot down I had to turn the volume down as it became very loud and I was convinced that I was onto something but still no target, I dug another foot out of the hole by this time the Z was going insane as if I was on top of my pick and was certain it wouldn't be long before I had my target out...Wrong all of a sudden nothing ? I checked everything , my settings and all the dirt out of the hole it was gone
I filled the hole and moved on bitterly disappointed.

My question is what my have caused this am I missing something ???

 

[Mike70]

Any chance it could have been mercury? small amount of it maybe thrown into some old diggings, and when you uncovered it, it simply evaporated, or just spread into tiny molecules. Just my thoughts on how a big signal can just vanish.

Mike70.

 

[BigWave]

I've had two of these with my 4500.
The first at Dunolly last year was a screamer, that suddenly disappeared. I noticed small gravel disappearing down a large spiders hole (I think it was at least). I marked it with a stick and left (needed to head home). It was driving me crazy, so went back a few weeks later with mardymoose (a PAer) and lady friend with a pit bar purchased for the job. We were down around 6 to 8" in hard ground before Mardy's 5000 picked up the signal again. Finally, out popped a 3.83g nugget. We were sweating!
Another similar was at Talbot. Was getting very loud and sharp. Went into pin-pointing mode, the detector made some strange noises, quickly getting weaker until it too disappeared. I again noticed many small holes (too big for spiders this time though) as we were digging, so again I assumed that it had disappeared down one - hence the strange noise as it started tumbling down. Unfortunately we (daughter and I) never found that one. Was one of the only holes we've left un-filled as she insisted that we return another day to keep digging (even if only for a bullet/slug). We went back ~ two weeks later to resolve, but eventually gave up and filled it in. Pretty sure we know what happened, but will never know for sure.

 

[Gravity]

Thanks BigWave, It's been eating away at me so much so that I have to go back to try to solve the puzzle...
The signal was just way to loud the detector was screaming louder than hovering over tin or metal , now just have to wait till some of this water subsides as more rain is on the way.

 

[Old Fred]

Had 2 holes in nth qld same thing . Returned next day with bigger digging tools and could not find any thing one hole and a 2 gramer in the other

 

[Nightjar]

Maybe a long shot Gravity, and not knowing anything about the Z.
Could it be you have not pinpointed correctly and you have heaped the soil from the hole on top of your target?
With the first use of a 20" NF on my 4500 I did once make a mistake and the back of the coil was where the target was?

 

[old hand]

Yes I cannot speak for the Z but have had this with the 5000s and the 4500s not sure if its related to the wet ground or not regards john

 

[Gravity]

Maybe a long shot Gravity, and not knowing anything about the Z.
Could it be you have not pinpointed correctly and you have heaped the soil from the hole on top of your target?
With the first use of a 20" NF on my 4500 I did once make a mistake and the back of the coil was where the target was?

The thought did cross my mind, at 2 foot down I hit clay that stuck on my pick...I do remember giving it a wipe as I was wearing gloves It could be that the target was stuck inside the clay that I tossed away...Oh no would that be it

 

[nuggetino]

Have had this happen with wet pockets of clay but also in dry ground at depth. Their make up is like that of a hot rock I'd imagine. As the layer is dug through the signal quickly disappears. BTW if you're lowering the coil into the hole and do not have much room for coil movement you can pick up false signals that won't GB out. In another instance I've actually managed to not only dig a target out of the hole but somehow fling it a few feet clear of the pile. Filled in the hole scratching my head then found the target as I started detecting again.

 

[Gravity]

Think your right, when I lowered the coil into the hole there was no room to move and lost the signal, I should have widened it out and ground balanced again.
I'm just going to have to make the 6 hour round trip again to find out , the thought of having potentially lost my 1st Z nugget is eating away at me.
Lessen learnt.

 

[Old Fred]

The great thing about this forum is others have had the same thing happen .U probably right i may have lost target off me pick in a lump off half dried clay i wiped of with my hand clear of the hole . I dont remember running my detector in a sweep around the hole to see if this is what happend . It was in a very remote spot and i have a gps on the hole .(lucky i had not deleted it ) .I will check it out next month when i go to Ravenswood cos it proberly sitting near surface . One of the good things about prospecting in remote areas not any other prospectors covering u ground

 

[Swinging & digging]

Hey guy's was hoping someone could help with this question,

Was in the G.T last weekend and had a great low signal from the Z, after about a foot down I had to turn the volume down as it became very loud and I was convinced that I was onto something but still no target, I dug another foot out of the hole by this time the Z was going insane as if I was on top of my pick and was certain it wouldn't be long before I had my target out...Wrong all of a sudden nothing ? I checked everything , my settings and all the dirt out of the hole it was gone
I filled the hole and moved on bitterly disappointed.

My question is what my have caused this am I missing something ???

The Z will occasionally react to carbon, old burnt out stump from years ago!
Or maybe mineralisation? was the ground a very rusty red colour?
I have been told that were lightning has struck the ground it can do weird things with certain minerals.
I had similar situation to you around a year ago and dug up some very strange red coloured rusty rock after breaking it down and crushing it with my pick signal vanished?

 

[Nightjar]

I'm just going to have to make the 6 hour round trip again to find out , the thought of having potentially lost my 1st Z nugget is eating away at me.
Lessen learnt.

Not wanting you to have sleepless nights BUT in my years of detecting have personally witnessed a clean 35g nugget, a large iron stone specie with 42g AU AND a large quartz specie with 53g of AU come out of holes left open by previous prospectors.
How they walked away from these targets will never be known?

 

[Teemore]

When using the SDC I will always detect over other peoples holes, filled or not, haven't had a great year but would say 1 in 10 pieces recovered comes from a previous hole, on a couple of occasions have recovered 2 pieces.
Think the GPX/GPZ"s may pict them up initially but then lose them in the scrapings.
Thanks, I'll take whatever is there.
Cheers T.

 

[Dignit]

My bet it will have been wet clay. I've had many of these of late. First couple fooled me but now have a couple of things to check. Sweep the coil over the top of the hole. If you are not still getting the signal it's probably wet clay. I've found the signal remains strong and can even get louder, but more often than not, only when the coil is in close proximity to the bottom of the hole. At normal ground level it goes. If it was a nugget by all accounts you should still hear it. Also check the soil coming out. Is the coil reacting to that? I've been finding in situations like this it does. I also widen the hole and ground balance in the hole. If signal fades or goes I consider it wet soil. And normal if you ground balance in the hole the sides then react. I've tried ground balancing out nuggets and have never been successful. With all this wet weather in the VIC GT this has been a regular occurrence for me. This was with a 15" Evo and 4500 so would say similar to the Zed.
Cheers

 

[Moneybox]

I rarely use a magnet but I've seen Mrs M get into strife with it from time to time. She uses the SDC so it's never deep but she'll have a strong signal disappear and when I check there's usually a thin bit of metal stuck to the magnet on her pick. It hides there in the fine iron dust that the magnet collects. I prefer to go without the magnet and actually find my target even if it is a bit of steel. I did get caught on our last day of detecting where I dug up somebodies pick magnet and when I lost the signal I eventually found it stuck to my pick.

I've also had those beautiful signals in the rich red soil that I eventually realise are in the dirt pile as well. Some detectors react differently but my mate with the GPZ7000 has a lot more trouble with bad ground than he ever had with the GPX5000 working the same ground.

 

[Mickkat12]

I'm currently battling the same thing near a tree , the sound came back and disappeared in the middle of old diggings going back for round 3 with the z

 

[Minelab Gold]

You will also notice in some instances when sweeping across a tree root that is exposed on top of the ground when you swing across ways it can return a false signal much like ground noise, then when you swing parallel along the root the noise will go away - this is a void in the ground the detector doesnt know about the root it only processes mineral content. I had this the other day digging between 2 tree roots very hard because the tree roots were roughly 100mm in diameter and only had maybe 90mm between the roots - I had a solid faint signal and put it down to the high iron content mineralized clay - even ground balance the sound was still there - but the only way I could get a clear swing was across the tree roots - so my conclusion was this void mixed with the red clay was the reason. Many nuggets under tree roots over the years

In regards to the target - I had this the other day when I found a small piece - the target sounded solid and clear like a 303 piece of lead about 4 inches down - when I scraped it got slightly louder, when I was down 6 inches the sound was screaming - I knew by pinpointing it was close to the top so I dug around 3 inches and removed the target - when I looked in the pile nothing - absolute nothing in a 2 meter radius around the hole - I opened the hole wider - nothing again - it was puzzling, I scraped dirt back into the hole and searched the dirt and heard a little faint signal and managed to find a target - but the target was not screaming like originally and I couldnt replicate the sound no matter what I did - it was a flat 0.5gram piece of Gold and even when flat or on the side I couldnt replicate - I couldnt even hear it at 2 inches below the coil so how could this be the target. I dug out a further 4 inches just to make sure it didnt slip down a crack in the ground

We know of the Halo Effect but how much does it effect the target and how many times have we had this halo but too faint to tell because we usually get all of our targets out

 

[ROB 65]

Hi Mi kkat12 have found pleanty of signals close to trees when digging and finding roots cut them with pick and signal disappears. Making sure your ground balance is correct helps. And Changeing gold modes will help. keep digging.