gpz7000 signal - just disappeared

Just asking, we had a couple hrs with the 7000 and after digging lots of lead we got a signal that was a 'dig me' signal. When i passed the coil over the spot again there was no signal. I thought that was strange so swing coil on some ground adjacent to spot then swung it back over the spot again with another good signal. When i swung coil back again signal had gone. I was in dificult and high yield, so i changed to general and swung back over spot with a signal again but then subsequent sweeps there was nothing. Tried different settings and all the same.
so we dug about 2"of surface and then there was constant signal so kept digging with signal getting better and better.  We got to about 8" and by putting coil in hole so 2oclock was in bottom of hole it was overloading.
we opened hole up larger and signal still there.  We dug to about 10 to 11" deep and then signal seemed to be not as strong and the further we dug down the weaker it got. Then seamed to dissapear. We could not find signal in overburden and after lots of boot scraping to mebe flatten out a flat target we never got another signal. Ended up filling in the hole with nothing found.
What tha!!!!   A ghost signal that we really thought was a definite target. Even the ground went from topsoil to the good quartz gravelly material that in this area was where gold had been found.   This is in adelaide hills.
can anyone shed some light on whats happened?   TG

The machine requires a good wide hole when your target is deepish, more than the 5 needed.
Had a few of these myself, usually hot ground well defined by the 7 , it is a frisky unit.
gravel

I just could not believe the signal we were getting then it is gone. One would assume that the target was out of hole sitting in the onerburden. Not the case. And when the signal started to get less that made no sense.  TG

I've had a similar signal a couple of times, but only about 5 inches deep. It turned out to be a concentrated shotgun blast of fine birdshot. The gun must've been discharged very close to the ground to have such a tight spread and depth. Could also be a decomposed specie ???

Will be interested to see how you get on travelergold.
cheers.

Yep had one of those last weekend myself. 10 inches down and overloading, my mate and I thought we were on to a winner but like you it just disappeared. We were pretty dismayed and aall edIit quits after that.
I have some video of another day where there were dig me signals everywhere on an old patch. All were ground noise. Pretty frustrating.

well fellas i have to relay my testing on a 12gram flat nug in a 9x9 inch posthole 18 inches deep, i dug in the middle of hot pink shale hotrock spot in gold country.
in high yield, difficult, sensitivy 20, threshold 10, no smoothing, volumes 10. in auto ground balance.(yes i know, sens too high and threshold too low, but that is not what this experience is about)
i was getting a signal that would have pulled me up, but with about eight broad swings across the hole, the signal dissapeared. moving around for about 10 meteres detecting, back again to the hole, it was back again, but disappeared with some continual sweeps. it consistantly disappeared with broad sweeps over the hole????

so went prospecting for ten or so meters, found heaps of ground noise to cancel out with the quick track button held and pumping up and down, reducing their signal. back at the hole, the 12gram nug was obvious again. so treating it like a ground noise and quicktracking OVER it, it got louder! for several sweeps, then disappeared with continual sweeping.

it did this several times. were the hotrock surrounds overpowering the target signal? balancing over the target made it louder?

according to the manual for the 7000, pumping the coil in quicktrack, upsets the ground balance, and should be swept.
JP says differently. this experience says, there is something to what JP is saying, but the big surprise for me, was pumping up and down OVER the target, increased it response for a few swings, but reduced the response from groundnoise.

dont know if you followed all that, i am more confused then ever. bloody z is going to drive me grazy ... kev

So maybe there is something to putting the GB into manual when working a target?  Someone suggested that in the "early" days but then the experts said that the Z will not track out a target.  Worth a try in the situation encountered.

Thanks Kev for posting that test, certainly food for thought.

So many faces to this machine. Knowing the strengths and weaknesses and then working within them should be our goal, but first we need to define them, your post is one more piece of the puzzle.

Cheers
Kev.

pablop wrote:So maybe there is something to putting the GB into manual when working a target?  Someone suggested that in the "early" days but then the experts said that the Z will not track out a target.  Worth a try in the situation encountered.

I've been thinking about this too pablop. There's been quite a bit said lately about having metal on ones body interfering with the 7k target retrieval. I wonder what is all this metal, i.e. pick, WM12, watch, cellphone, spectacles, wallet, belt buckle etc., doing to the GB if left in Auto? Surely it must be messing with it since it's such a temperamental little brat.

I think that new pick JP uses is stainless steel?
Stainless doesn't maintain eddys like carbon steel so I would expect could be carried closer to the Zed without upsetting it.

But I've decided from now on to always engage manual GB before I put the Zed down to start digging a target. Not with any fear of tracking the target out but simply maintaing a clean GB record. It takes so long to supposedly obtain the ground matrix data, why corrupt it and possibly miss future targets by introducing spurious metal targets?

Cheers.

I sett my user button to toggle between Manual and Auto ground balance.
The 7k is alot better at not tracking out a target than the 5k but it is not infallible.
My testing proved that it can indeed track out a good target! even a larger one!!
So I just flick into fixed when I recover a target, which is easily and quickly done when you program the user button to the ground balance menu.

I also avoid repeatedly swinging over a potential target!
Insead I swing over the target twice then swing around near the target for a couple of swings then check it from a different angle and repeate the process of swinging away from the target.
Then if I'm still interested I flikck into Manual.

If the target dissapears in Manual you know it was just a ground noise that are quite common on the 7k.

I configured my user button the same after the early discussions, and use as you do Goldhound, just to be on the safe side and haven't "lost" a target using this process.

Yes thanks Dale, I appreciate you've been advocating this procedure for a while now and I think I'm a full convert.
I did have the user button set for GB function but after a full reset it was gone, and I never got around to reprogramming it.
Darn pain that is trying to remember in the field to set everything back to how you like it.

Cheers
Kev.

Thanks for the replies. Next time we go up there will take the 4500 and recheck that hole. Goldhound, i can see what you are doing / suggesting, but my target initially i could only swing over once and when i swung the coil back over the spot signal was gone.  The signal only become really good as we dug it then as stated was gone - vanished.  Like some posts this machine seems to have its little quirks and one has to learn and decipher it.  I am not knocking the machine as have picked up small lead shot that my 4500 would have never seen. A large learning curve with it. May have to see if can do a day course with nenad to pick up finer points. TG

The same thing has always happend to me with all previous detectors travelergold.
Its just part in the parcel of detecting in a gold field with varying soil conditions, anthills ect.
I have found the 7k to be much quieter than predecessors and less susceptible to ground noises than the predecessors.
It just takes a bit of getting used to and once you do in certain ground types that masked alot of gold it is suddenly detectable in the right settings with the 7k some of the gold is larger and shallow too, but masked by the soil conditions.
The same gold is undetectable no matter the coil or settings on the 5k.

alchemist wrote:

But I've decided from now on to always engage manual GB before I put the Zed down to start digging a target. Not with any fear of tracking the target out but simply maintaing a clean GB record. It takes so long to supposedly obtain the ground matrix data, why corrupt it and possibly miss future targets by introducing spurious metal targets?

Cheers.

This is the other reason and the main reason why I use Manual for targt recovery, I have eluded to this previously in other posts early on just after its release.
But I dont belive its effected at all by spurious targets but rather I think if the detector sits idle for too long that it is recording no ground signal data over good gb data and this throws out the ground balance.

Goldhound, yes the machine is so much quieter. And is more sensitive as well i believe. In WA we got what we called ghost signals on a regular basis with the 4500 and found if we tipped a half cup of water in hole the signal was gone, but never tried it the other day here. I will go back there with the 4500 and see what that does when i am having a good day. just to check. TG

GoldHound wrote:
but rather I think if the detector sits idle for too long that it is recording no ground signal data over good gb data and this throws out the ground balance.

Interesting thought's there Goldhound, without questioning your finding's is this something that others have noted?

Peteren wrote:

GoldHound wrote:
but rather I think if the detector sits idle for too long that it is recording no ground signal data over good gb data and this throws out the ground balance.

Interesting thought's there Goldhound, without questioning your finding's is this something that others have noted?

Not that I know of.
I think about every aspect of what I do and assess the variables and then test for effects by eliminating or adding the variables one at a time.
Lots of work but it gives me the upper hand when making a decision on how to ATTACK!!!!

travelergold wrote:Goldhound, yes the machine is so much quieter. And is more sensitive as well i believe. In WA we got what we called ghost signals on a regular basis with the 4500 and found if we tipped a half cup of water in hole the signal was gone, but never tried it the other day here. I will go back there with the 4500 and see what that does when i am having a good day. just to check. TG

That sounds like accumulated salt's, by wetting them you redistribute the salts as they are highly water soluble.
They are common in flatter areas common in central Australia and WA.

GoldHound wrote:

Peteren wrote:

GoldHound wrote:
but rather I think if the detector sits idle for too long that it is recording no ground signal data over good gb data and this throws out the ground balance.

Interesting thought's there Goldhound, without questioning your finding's is this something that others have noted?

Not that I know of.
I think about every aspect of what I do and assess the variables and then test for effects by eliminating or adding the variables one at a time.
Lots of work but it gives me the upper hand when making a decision on how to ATTACK!!!!

Cheers Goldhound, I'm with you on the "attack" methods.

On a side note, can I pm you regarding SA info?

Peteren wrote:

GoldHound wrote:

Peteren wrote:

GoldHound wrote:
but rather I think if the detector sits idle for too long that it is recording no ground signal data over good gb data and this throws out the ground balance.

Interesting thought's there Goldhound, without questioning your finding's is this something that others have noted?

Not that I know of.
I think about every aspect of what I do and assess the variables and then test for effects by eliminating or adding the variables one at a time.
Lots of work but it gives me the upper hand when making a decision on how to ATTACK!!!!

Cheers Goldhound, I'm with you on the "attack" methods.

On a side note, can I pm you regarding SA info?

You can pm me but don't assume that I'll tell you any of my spots or prospective spots.
I never share that type of info with outsider's.