Question For The GPZ Experts

[zortan]

Hello all,

After a long day of working on getting skunked and just before sundown I changed my detecting technique from a very Gerry way of detecting to a very Lunk way of detecting. ( rather fast vs. like a turtle). When I did this I started to find nuggets again, small guys like .1 and .2 grammers but hey, gold is gold right?

my question is two fold, does a large deep target sound the same as a very small shallow one?  Does the fact that I started to find targets again have more to do with coil control or does the GPZ need time to charge up the ground or something like that?

[jasong]

A few things happening.

The slower you swing a coil, the more time your coil is over a target and thus the "wider" (longer duration) a target signal sounds and the wider a target signal is, the less it can be confused for EMI. The faster you swing the detector, the less time the target is under the coil and so the target response you hear gets shorter until it becomes almost indistinguishable from EMI, so tiny targets get missed.

Tiny nuggets already have a "narrow" sounding signal due to being small targets. So widening that signal out by slowing down your swing can make them stand enough to determine they are good targets.

Re coil control: If your coil is angling up 1" at the ends of a swing and your detecting range for micro nuggets is only 3 or 4 inches, then you can be losing 25%-33% of your depth with just slightly bad coil control. It's easier to keep the coil flat at all points in the swing when going slower. Or, if the ground is uneven then you can keep the coil parallel to the surface much more accurately going slow. Also, the slower you go, the more you overlap swings and poke the coil into all possible areas around obstacles.

To answer your second question: a large deep target can sound the same as a small shallow one in so much as they can both be faint and not very "wide" signals. But sometimes a shallow, small target will give a double blip as it passes over each straight section of the D's. whereas a deeper, faint target will be a single response at the center of the coil.

 

[LuckyLundy]

Z,

A slow and steady swing of any detectors coil, is a major factor in finding nuggets.  If I’m swing on and old patch or a juicy looking spot, my coil is real slow.  I’m not so much of a believer of a machine charging the ground, it’s giving the little extra time for your detector to send your ears then brain to comprehend as a target, with a slow swing.  Your next slow coil target, give it a test, swing your coil over it faster...lots of times you won’t hear this target at your normal coil swing speed.  Remember, this slow swing isn’t what you want to do Patch Hunting, your only looking for one shallow nugget when out hunting new ground.  You find that one and back off a couple notches and slow your coil swing to help establish if you stumbled onto a patch.  Your deep sounding nuggets sound vary and most will sound just like a little dink nugget...you always hope with each swing of your pick that it’s a deep one which will get louder as your hole gets deeper!  Keep on swinging!

LuckyLundy

[Gold Catcher]

I stick to JP's mantra: full range of motion swing (but slow) and strict coil control. The full range of motion coil swing has actually helped me greatly and I always try to remind myself of doing that. I have missed targets by not allowing the coil to sample enough ground to make the target stand out. Shallow targets give often a high/low response with double dip, whereas deep targets often give a low/high response with some lead time, meaning that the coil could already have passed the target) a the response is being generated. It's a SuperD, so the highest sensitivity are the two vertical lines on the coil (where the two receive D-loops are)

[zortan]

Thank you so much for the answers.  I got a flat tire today on the way out to the goldfield so my day got burned fixing that fiasco but I can’t wait to try the tips you guys gave me tomorrow!  It’s been a huge help and makes perfect sense.

 

[Gold Catcher]

Oh that sucks! I hope this did not happen in the middle of nowhere. Good luck with the GPZ. Btw, try out the swing arm. It makes all the difference for coil control and detector handling in general. I use it all the time without exception. I keep the clamp low on the shaft close to the coil.

[jasong]

Detecting slow is kinda the golden rule of accurate detecting. You can't really go wrong sticking with low/slow and digging everything. But, it's not the full picture with the GPZ.

Caveat: you can pretty much ignore everything I'm about to type for your entire detecting career and you'll still do just fine. If you are just starting on the GPZ, you should probably ignore all this for a year or two haha...

1. There are times when swinging faster will actually find you targets you missed going slower because the wide, slow target response blended into the wide ground noise.  Sometimes you want to widen your target signal, sometimes you want to narrow or sharpen the signal, and that determines what your swing speed should be. Sometimes I swing slow, then do a 2nd faster swing over a suspect target, sometimes vice versa. 
2. In Auto ground balancing, a similar effect can often be accomplishied by jabbing your coil in and out over a target, and so you can keep your swing speed the same (easier on my elbow). You get used to how the ground coupling changes as you lift your coil throughout the day, and it's usually not the same as how the coupling between a target changes. The target coupling will stay sharp, the ground coupling will often vary with each jab. I can "feel" it.  I jab-jab-jab almost all my targets subconsciously after swinging over them first to get an idea if a signal is target or mineral, it speeds up detecting greatly for me. I've been lectured on this, but I don't care, it works.
3. Jabbing your coil in and out over a target (aka: bad coil control according to some) can also sometimes force a normal sounding solid tone target to flip and do the warble when you are in Normal and in mild ground. So too can "nosing" the coil into a target. I always thought of it as a tone curl though, because the goal is to smoothly curl the tone over and back again like a whammy bar on a guitar, not so much a discrete warble fluttering. Targets may or may not curl by jabbing, but hot rocks almost never do. That is often useful information because I dig 100% of tone curl signals.

When I detect with the GPZ I feel as if the mag field emitted from the coil is like an imaginary extension of my hand reaching into the ground. And intentionally changing the coupling between the mag field and the ground/target is like moving my fingers around in the sand to use my sense of touch to try to guess what is hidden down there. 

Detecting purists watch me work, clutch their pearls and fall onto the fainting couch in abject horror.  

[Gold Catcher]

All good points. Everybody has their own way of detecting styles and that is the beauty of it. Amazing actually, the GPZ seems to make philosophers out of their owners, me included...I don't think any other detector comes even close of doing that ?

[Gerry in Idaho]

Great post and and answers already provided.

Just wanting to clear up a few things.  My Settings are totally backwards of Lunks, but yet we both do much better than most and we are actually pretty close on nugget hunts/counts.  He might get a couple extra than I on one day and then I'll do the same the next.

Proper Coil Control is MOST important and we both are spot on.

Sweep Speed - This is an interesting one as Lunk does sweep slower than I do (all the time).  Even when he's looking for new patch, his sweep speed is slower than me.  

I adjust my sweep speed based on the situation (as most folks should do) and when looking for Patches, yes I am faster than Lunk.  When hunting a site we have hunted before, I feel I am still faster than Lunk.  Now put me in a small wash I know there is still a few pickers left, and I could spend 20 minutes in a 20' long by 8' wide wash.  I go much slower at that time as I am also scuffing every little broken/change of the threshold.

Here's what I tell the customers at Rye Patch.  If you know nuggets have come from a certain wash, it is best to slowly and methodically work it and not worry about covering a lot of ground.  You are better off to go slow, keep the coil on the ground across the complete sweep width and only worry about how well you cover that piece of ground, not how much ground to cover than day.  

If you are in an unknown area, (driving down the road and see some good looking terrain), you make a decision to test it, then going so slow as mentioned above, is not as beneficial, so I would swing faster and cover more ground.

Here is where Lunk/I and most other well known and Successful GPZ users stand.  We all have found hundreds of nuggets (some of us thousands) and we have trained our our bodies, coil control  and ears to hear a certain signal and nothing but time and experience can do that.

I'll use a simple example that might make sense:

2 guys fishing side by side with same rod, same line, same bait and one guy catches trout so easy and the other guy can't seem to catch even 1.  The guy catching the trout knows the feel of a slight bite vs the bait hitting the bottom.  He has perfected his skill and all the other guy can do is watch, listen, ask questions, learn...and if he keeps at it, the 1st of many will happen.

You are on your way to great things, as long as you don't give up on yourself...and continue to perfect your skill.