How do you tell the difference between ground noise and a true target signal?

[davo85]

Aha, whenever I was in a clay area today, I just walked away and went to the more gravel areas. Sounds like I had the right approach.

It's only the clay that's hurting my brain. I'm very confident of digging up something in all other circumstances.

 

[20x]

You would think that for $8k minelab would have solved this problem. The funny thing is I can pull tiny bits and tiny lead shot out of loud and WET clays with the gold monster using sound response and visual reading. Maybe they need to create a hybrid..

 

[davo85]

Yeah, it's the only trouble I'm having. It gives off a very convincing sound too. I don't mind digging up pellets all day, but it get frustrating digging up nothing. Luckily for me there is lots of gravel here in certain areas.

 

[Hawkear]

When the clay is wet and/or giving off lots of target like ground noise, maybe that is when we should be doing target testing to see if our ears can tell the subtle difference.
With the earlier GPs & GPXs, I seemed to be able to pick the difference purely by ear. Never felt I could do that with a 7000 or 2300.
Still don’t know if I imagined it or whether it was something to do with more signal “processing” by the modern electronics.

 

[davo85]

When the clay is wet and/or giving off lots of target like ground noise, maybe that is when we should be doing target testing to see if our ears can tell the subtle difference.
With the earlier GPs & GPXs, I seemed to be able to pick the difference purely by ear. Never felt I could do that with a 7000 or 2300.
Still don’t know if I imagined it or whether it was something to do with more signal “processing” by the modern electronics.

Hello Geoff. After today, I know exactly what you are saying. I found several sub gram pieces today, and I can definitely now tell the difference most of the time. I've noticed if it's gold, it's a short mellow sound. If it's clay, it's still mellow, but it's a longer and more drawn out sound. I still got fooled a couple of times today, but nothing compared to before.

 

[Hawkear]

Hello Geoff. After today, I know exactly what you are saying. I found several sub gram pieces today, and I can definitely now tell the difference most of the time. I've noticed if it's gold, it's a short mellow sound. If it's clay, it's still mellow, but it's a longer and more drawn out sound. I still got fooled a couple of times today, but nothing compared to before.

Appreciate that follow up Davo.
Do also remember that larger deeper targets can also “broaden“ the signal. So even an expert trusting his ears can occasionally be mistaken.
It’s all about time management, and in damp conditions like the present or in certain grounds that we sometimes encounter you just can’t dig everything and you have to select your best targets in the time you have available.
That means more time with your detector detecting, not digging, not target isolating, as I’ve seen many spending excessive amounts of time doing, just more effective swing time to find those real targets.
If you start finding gold you can always go back and re-examine those more marginal signals.

 

[Nightjar]

it the tree is a stump, I've probably been there & thrown my junk finds into the trunk

Have found where someone had dug a stump and removed it from the ground. "Lot of back breaking work."
Swung my 4500 over it and got a clear/loud signal.
Buried in the trunk was a number of 303 bullets, someone in years gone bye had used the trunk to display a target.

 

[davo85]

Appreciate that follow up Davo.
Do also remember that larger deeper targets can also “broaden“ the signal. So even an expert trusting his ears can occasionally be mistaken.
It’s all about time management, and in damp conditions like the present or in certain grounds that we sometimes encounter you just can’t dig everything and you have to select your best targets in the time you have available.
That means more time with your detector detecting, not digging, not target isolating, as I’ve seen many spending excessive amounts of time doing, just more effective swing time to find those real targets.
If you start finding gold you can always go back and re-examine those more marginal signals.

Thank you. I'll keep that in mind re deeper targets. I feel I've done way too much digging, and I like the idea of spending more time detecting.

 

[Hawkear]

Have found where someone had dug a stump and removed it from the ground. "Lot of back breaking work."
Swung my 4500 over it and got a clear/loud signal.
Buried in the trunk was a number of 303 bullets, someone in years gone bye had used the trunk to display a target.

A mate once spent a fair amount of time digging down alongside and under an old stump. The result apart from a couple of near herniated discs was a beer can that had been dropped down the hollow in the stump. I’m pretty wary now of hollow stumps like that for all the rubbish people seem to like dropping in them.
Another can episode was in WA, when one of our group had a good signal coming out of seemingly solid rock. After we had spent some time helping him chiselling down (fortunately not overly long), I noticed a slight depression a couple of feet to one side. Clearing the top, it turned out to be an angled drill hole and the signal my mate heard was a can someone had dropped down it.

 

[user 12139]

Have found where someone had dug a stump and removed it from the ground. "Lot of back breaking work."
Swung my 4500 over it and got a clear/loud signal.
Buried in the trunk was a number of 303 bullets, someone in years gone bye had used the trunk to display a target.

.. poor fella, must have thought for a moment he finally found a money tree.
Wasn't me NJ, I lived in WA for 17 years but foolishly never did swing a detector there, still kicking myself

 

[Nightjar]

.. poor fella, must have thought for a moment he finally found a money tree.
Wasn't me NJ, I lived in WA for 17 years but foolishly never did swing a detector there, still kicking myself

Bungarras have a taste for the dregs left in cans cast out the window, they drag them down into their holes and become a great signal for the unwary prospector.

 

[user 12139]

Bungarras have a taste for the dregs left in cans cast out the window, they drag them down into their holes and become a great signal for the unwary prospector.

pea plant slugs love beer too

 

[Dave's Office]

pea plant slugs love beer too

So do I

 

[user 12139]

I suppose we should get back to the real topic here.. how do you tell ground noise from targets?
Well for me, I'll swing over the target in 2 directions like this +
Generally one direction will be more definitive than the other with ground noise whereas a target more often than not will be equally definitive in either direction... but as they say dig all targets

 

[Gregyem]

I've dug heaps of charcoal signals, I'm awake up to them now and have finally worked them out.

Any idea what the physics/chemistry is that makes charcoal interact with the detector field ? In the old days they used to make carbon resistors for electronics. Is it perhaps this weak conductivity of electricity that is at play hear. But if so, I wonder why fresh charcoal seems to be noisier than older stuff.

 

[Dave's Office]

I'm sure Goldierocks can answer that question ☝

 

[user 4485]

Any idea what the physics/chemistry is that makes charcoal interact with the detector field ? In the old days they used to make carbon resistors for electronics. Is it perhaps this weak conductivity of electricity that is at play hear. But if so, I wonder why fresh charcoal seems to be noisier than older stuff.

Charcoal is made up of carbon & carbon is a conductor (although a poor conductor) so that is what causes it.
I've always assumed it's only the charcoal that is of a very high carbon content that reacts due to a lot of charcoal I've passed over not giving any signal at all. More ash & other residues rather than high carbon charcoal left behind.
I don't think carbon degrades?
Lower oxygen fires apparently leave a charcoal that is higher in carbon too so the type & intensity of the fire may also make a difference to the reaction.

 

[19.3]

Ever been around a tree got a target then as you dig you start to suspect ground noise but it sounds too good & ground balancing doesn't seem to work? It can end up being a root! (GPZ 7000 are good rooters (not necessarily talking about the owner - but in my case))

My fix for this scenario is to wave the coil across the trunk of the tree if it sounds like what you're digging STOP DIGGING!

I had a small, dead tree once which gave off a very strong signal, first at the roots, then all the way up the trunk. It was a very strong signal- and left me quite stunned at the time. And no, it wasn't hollow.

 

[Hawkear]

Charcoal is made up of carbon & carbon is a conductor (although a poor conductor) so that is what causes it.
I've always assumed it's only the charcoal that is of a very high carbon content that reacts due to a lot of charcoal I've passed over not giving any signal at all. More ash & other residues rather than high carbon charcoal left behind.
I don't think carbon degrades?
Lower oxygen fires apparently leave a charcoal that is higher in carbon too so the type & intensity of the fire may also make a difference to the reaction.

I‘ve also wondered why charcoal patches seem to give a signal some times but not every time.
Maybe as suggested could be more to do with the burning of the clay around a burning root. This would provide a mechanism for altering the soil mineralization around the charcoal patch.
When detecting I often encounter ground noise from a small patches of deeper coloured clay associated with charcoal clearly present and I just assumed it was the charcoal responsible. But then I can also remember encountering ground noise from the same reactive clay patches of a similar burnt colour without any significant charcoal around. Maybe I didn’t inspect hard enough.

 

[Nightjar]

This covers it pretty well

This is one of the best demonstrations regarding ground noise and overcoming it.