GPZ7000 - Deeper LARGE TARGETS

Hi GPZ7000 owners

Have you found any large targets?

I read a lot of small bits are found with the 7000, I know the other units can find large gold, but I was hoping the 7000 may have picked up large specimens at depth where the 4500 - 5000 will not detect.

Morning Aussiefind don't own one myself but do know others that have taken the leap but none have spoken of large deeper finds, or maybe there just not telling???

Captn

Apart from the odd gram/multi grammer here and there,I personally haven't picked up anything in the likes of larger slugs or specimen gold at extreme depths Ausiefiend,but judging by the depths I have had over gold in the past,I have no doubt that if the larger slug of gold or specimen,were there,just out of reach of the GPX 5000 (using a similar in size coil to that of the 7000) the gold would be found with the 7000.
Overall,half my finds so far,would have been well within reach of the 5000 using a similar in size coil to that of the GPZ. The GPZ 7000 is no miracle detector,but it does find gold,or certain types of gold,at depths where others fail to.
The key to the GPZ's success is going "Low and Slow".
I also agree with the Capt.here,that not everybody reveals,what they have found and at what depths they had found it in,using the GPZ 7000.
Lets face it,we might all be buddies out in the field,but the moment the detectors switched on,its every man for them selves no?  

Cheers Kon.

In the Vic diggings over Easter I dug out a piece of Brass around 1oz in weight around 60cm+ down and 5000 (smaller elliptical coil) could not hear it, later on found a 8gm or maybe 12gm similar depth ditto bolts similar depth was very impressed at it depth finding abilities, which suggested to me should be great in WA, where the topsoil has levelled off deep ground, but gold I found was nearer the surface and found on Hi Yield.

My theory at the time was the 7000 at the bottom of the dig hole and angled out at the bottom could find gold that the miners missed, but signals create a lot of digging and sweat. Used a 45 with small coil for pinpointing along with crowbar etc.

Peter

my most notable find of 73gram down a bit over a foot, screemed at me, lifting the coil more than a foot above ground,it was still obvious, damn near didnt dig it, though it had to be rubbish just under the surface. needless to say the other machines would have found it also, but before digging it was very obvious at over 2 foot (being one foot of air)

second noticable dig was a 8.3gram, very obvious sweet signal at 16 to 18 inches, in general, difficult, but with sensitivity at 19 and volume at 15, with max volume at 10. the signal was so good i was guessing it to be a few grams at about a foot deep. that was impressive.

at the same spot, a confusing broad ground noise had me remove several inches of what looked like fine whitesh ash from a burnt stump, the signal remained confusing and not a "dig me" yet. several more inches off the top, i finally had a obvious dig me sound, located a rusty tack, plus a half gram nugget in the soil after down six more inches or so, but there was still a strong signal in the hole. it turned out to be a flat 2gram nugget that had to be down somewhere about 16 to 18 inches in total. with so much activity in the one hole, i cant say for sure what attracted me to it first off, other than to dig anything until you discover what it is, glad i did.
i have been back to a spot where i have found plenty of small nugs before, the largest being a 1.5gram down over a foot with the 7000 in high yield, normal, sensitivity 19, target volume 15, max volume 10, with smoothing low. (previous best gets here with the 5000 was a ,6grammer at about 10 inches in general normal with a 17x11 mono coil NF). ... so i was back again to run the 7000 in general, normal, sens 19, target volume 19, max volume 10, smoothing off. going slow, as you would with a good spot, i got a 2.2 and 2.0 pair of nugs down over 15 inches. that was very impressive. sleeping on that, saw me back the next day to try the spot in DEEP, normal, as there is no gravel bed or bottom to this soil. i got a 5.1gram nugget down over 15 inches, again under some charcoal that was on the surface. i have learnt to test any undistrubed charcoal, as that is still virgin ground that a lot of fellas, and a lot of machine cant handle.

hope the above gives you confidence that it has for me, that the 7000 is indeed a bloody good machine ... kev

Hopefully even better,with the introduction of the new software-update Kev.

Cheers Kon.

kevlorraine2 wrote:my most notable find of 73gram down a bit over a foot, screemed at me, lifting the coil more than a foot above ground,it was still obvious, damn near didnt dig it, though it had to be rubbish just under the surface.  needless to say the other machines would have found it also, but before digging it was very obvious at over 2 foot (being one foot of air)

second noticable dig was a 8.3gram, very obvious sweet signal at 16 to 18 inches, in general, difficult, but with sensitivity at 19 and volume at 15, with max volume at 10.  the signal was so good i was guessing it to be a few grams at about a foot deep.  that was impressive.

at the same spot, a confusing broad ground noise had me remove several inches of what looked like fine whitesh ash from a burnt stump, the signal remained confusing and not a "dig me" yet.  several more inches off the top, i finally had a obvious dig me sound, located a rusty tack, plus a  half gram nugget in the soil after down six more inches or so,  but there was still a strong signal in the hole.  it turned out to be a flat 2gram nugget that had to be down somewhere about 16 to 18 inches in total.   with so much activity in the one hole, i cant say for sure what attracted me to it first off, other than to dig anything until you discover what it is, glad i did.  
i have been back to a spot where i have found plenty of small nugs before, the largest being a 1.5gram down over a foot with the 7000 in high yield, normal, sensitivity 19, target volume 15, max volume 10, with smoothing low. (previous best gets here with the 5000 was a ,6grammer at about 10 inches in general normal with a 17x11 mono coil NF). ... so i was back again to run the 7000 in general, normal,  sens 19, target volume 19, max volume 10, smoothing off. going slow, as you would with a good spot, i got a 2.2 and 2.0 pair of nugs down over 15 inches.  that was very impressive.  sleeping on that, saw me back the next day to try the spot in DEEP, normal, as there is no gravel bed or bottom to this soil.  i got a 5.1gram nugget down over 15 inches, again under some charcoal that was on the surface.  i have learnt to test any undistrubed charcoal, as that is still virgin ground that a lot of fellas, and a lot of machine cant handle.

hope the above gives you confidence that it has for me, that the 7000 is indeed a bloody good machine ... kev

kEEP UP THE GOOD FINDS

yep kon - just finished downloading the upgrade. had a talk with one of the developers in SA about three weeks back. he told me about it but swore me to secresy. my discussion with him indicated that my ongoing complaint about the unstable threshold (which has caused me to run in "bogene" settings, that is, with threshold at 1.) was about to be corrected. hope it does allow me to now try and use the machine as intended.
funny thing is, my couple of months use of the machine enabled me to find plenty of gold, i definately know it is a lot more capable than the previous offerings even WITHOUT USEING THE THRESHOLD it will be interesting to see if i can now do as good keeping the machine running quiet with the threshold in play... kev

Fingers crossed Kev,the new software upgrade,is and does all that is said of it. By the way,just to let you know,your 7000 wasn't the only one with a slightly erratic or unstable threshold.Its just that I/we tolerated & put up with it as you had. The threshold though I found,was not the main cause of instability,as much as was the slow auto ground tracking,causing unnecessary ground noise/falsing when swinging the coil to fast,before the auto tracking had time to kick in and cancel most ground noise/falsing out. That's why any 7000 operator,who picked up on this early,realised that Low & Slow,was the only way to go towards achieving a constant,stable threshold/ground balance when in Auto Tracking. Hopefully all this is put behind us now,with the new software upgrade.
Now,Minelab,surely we're one step closer to the introduction,of that new,larger "Super Deep" coil hey?  C'mmon Minelab.You Can Do It.  

Cheers Kon.

kon61 wrote:
Now,Minelab,surely we're one step closer to the introduction,of that new,larger "Super Deep" coil hey?  C'mmon Minelab.You Can Do It.  

Cheers Kon.

Jeez Kon, how deep do you want to go for those horse shoes.

Now,now there Harry. I have warned you to stay away from those large mullock heaps & old timers holes. At the rate we've been extracting old horse/donkey shoes out of the ground lately,it be only a matter of time,before we discover part of the horse or donkey still connected.
Look on the bright side Harry,by taking away the old horse/donkey shoe,we are contributing to keeping the gold fields Iron free.

Cheers Kon.

Horseshoe at 22 inches. I thought that after 12 inches I was onto something good as it was hard compacted conglomerate type stuff, and looked like virgin ground, but at 22 inches, a rusty stain and their was my disappointing find.

Sounded good at the surface and all the way down.

Rob.

Youll see Tremain and I both dig some nice sized slugs and 4 leaders that were out of reach of the 5k in the next few vids that we are editing right now.

Now that will be something to look forward to. Good on Goldhound,I'll be waiting with anticipation.

Cheers Kon.

GoldHound wrote:Youll see Tremain and I both dig some nice sized slugs and 4 leaders that were out of reach of the 5k in the next few vids that we are editing right now.

Are they ready yet? I need some gold porn bad   ......what about now ...ready yet?...........huh?  are they?...... huh?? .....are they done yet? can we see them now?? .......are they done yet?........how about now?....are they done yet?

Wayne.

Digginerup wrote:

GoldHound wrote:Youll see Tremain and I both dig some nice sized slugs and 4 leaders that were out of reach of the 5k in the next few vids that we are editing right now.

Are they ready yet? I need some gold porn bad   ......what about now ...ready yet?...........huh?  are they?...... huh?? .....are they done yet? can we see them now?? .......are they done yet?........how about now?....are they done yet?

Wayne.

Where's your manners Wayne?      What do we say? Hmmm?  That's right, we have to say pl_ _ s _, now go sit in the corner.

One is rendering as I type this.
But then I have to post it to dave to put up as my internet is limited

GoldHound wrote:One is rendering as I type this.
But then I have to post it to dave to put up as my internet is limited

Hi mate, look forward to receiving it Nicki just got us hooked up to the NBN network so it should upload alot quicker this time around.

Hi Aussiefind.  I have used most of the earlier Minelab gold detectors over the last 20 years or so. The 7000 has led me to dig some large targets at depths over 60 cm. All were 1860's trash but not large lumps of iron, sought of 10cm x 1cm iron pieces and a small chisel end. I believe the 7000 hears deep targets in moderate/high ground noise soils better then all earlier minelab models. The SDC is also good in hot ground...but its design is for shallow gold only...no depth.  

I continually notice how deeper and bigger the holes are I am digging with the 7000 compared to the 4500 for gold from 0.5 gram to 1/2 ounce size- I have had the crowbar out about 6 times with the Zed to dig deep holes. If you own a 7000 you do need a crowbar in your vehicle.... Actually keep a crowbar handy if you have any Minelab gold detector.

The 7000 definitely detects specimens at depths far deeper then a 4500/5000 can find them at, and of course it sees small shallow specimens with dispersed gold in them that the 5000 just doesn't see.

I have just discovered that if I swing the 7000 ultra slow with a higher sensitivity/gain I can make out broad weak signals on very deep targets. The signals usually sound like barely discernable broad ground noise, and a few of them are ground noise, however some have been 4-5 gram nuggets at around  60 cm deep and large nails at bigger depths. The trick is I am scaping a few inches off and often finding it was only ground noise, but some were targets. The target signals were initially just so subtle in their response, just a variation in the threshold sought of.  All these targets were in ground that has been covered with coils by me and others many times.

I will say that I am happy with the performance of the 4500/5000 and if you have these detectors then its a matter of the users skill, research and perseverance that will make you successful and probably more successful then a 7000 user who is just learning....unless they are on very small shallow gold.

With the 7000's ability to find shallow small nuggets and not so shallow small nuggets, its edge over other detectors on specimens at depth...and as per you query...its abilty to hear deep targets in noisy ground... the 7000 has my vote on the best gold detector available(despite the design flaws, shaft to short, support pads that break, cigi socket charger leads that are too thin and break etc. now I'm ranting.

tributer

good report tributor,
i discovered this ultra slow trick a few months back, but until just recently hadnt realised what i had discovered.

a meter square patch that had produced a small nug, filled in, redone, a nug again, filled in, and redone again, another nug. all over a few days, as it was just beside where i sat on a log for lunch.

i was in the habit of restarting the machine, getting it running good, and testing on this small patch. on reflection, i was going VERY SLOW to confirm the machine was running good, and each time i was left mistified how i had missed that nugget before.

this beast, the 7000, is not as simple to use as we had hoped. there may not be many dials to fiddle with, but we have to develop alziemers on how we used the gpx machines. (fortunately for me, at being 70, i may already have some degree of advantage LOL).... kev

Thanks for that report Tributer. Low & slow is the general rule with any detector. It is amazing the signals you get when slow & low. Often I wonder how I missed them at earlier times over that ground. They just seem to really stand out. It is hard to keep slow when on ground that you are prospecting that gold hasn't been known to have come from. The old try to cover more ground quicker until you get a positive hit will often lead to missed signals...that is for sure, as many signals are VERY subtle & they WILL be missed at speed.

Good luck out there

JW

Tributer wrote:
I have just discovered that if I swing the 7000 ultra slow with a higher sensitivity/gain I can make out broad weak signals on very deep targets. The signals usually sound like barely discernable broad ground noise, and a few of them are ground noise, however some have been 4-5 gram nuggets at around  60 cm deep and large nails at bigger depths.

tributer

Good post tributer.
I found this out after doing some in ground depth testing several months back.

The 7 was getting targets way deeper than the X.
BUT the signal volume was so very weak it was almost inaudible. This is very frustrating as I'm convinced that the software function controlling the audio processing could easily distinguish these weak signals from the threshold and amplify them a whole lot more.

I think Minelab should rewrite the audio dsp function and fix it up as I'm convinced a lot of people are missing these targets, especially many older folks with hearing degradation.

I'll be soon testing a compressor/amplifier circuit aimed at expanding these minute but significant signals. If it works well and Minelab don't come to the party on this, and fix up the code, I'll post a how-to in th DIY section. Possibly offering a kit for those less able with circuits.

Cheers.

Hi Alchemist,
Your new amp project sounds very interesting, myself, being one with less than optimum hearing, so please keep us up-to-date on progress.
Many thanks, AUoptimist.

Will do AUoptimist.

I'm only just coming to grips with deep targets, none big yet, but it's only a matter of time in the field.

What I find interesting is that the 7 doesn't give the old "whee whoo" on deep small stuff, but more of a "hear me" and when it's a bit EMI noisy only the "me" seems to stand out, and even then is easily missed until you get your ear in tune.

Of course this is edge of detection stuff. I need to optimise the compressor frequency response to accentuate the higher frequency "hear" component, and just maintain the down note "me".

The bigger stuff will likely be a more wide "me here" response, so will need to do quite a bit of testing when I can get out of town again, so that all sizes are covered.

Cheers.

Hi Alchemist,
Thanks for the up-date, yes the 7000 is certainly a different kettle of fish compared to the 5000, my first detector.
So, keep up the R&D on the amp, I'm sure there will be quite a few 7000 owners both keen and greatfull to see what you can come up with.
Cheers, AUoptimist.

Alchemist, I am planning a similar project, I was surprised to read this! I have a couple THAT Corp chips waiting on my porch for when I finish up my prospecting trips end of next month.

I agree it seems like the audio functions should be able to emulate a compressor but they fall short. Taking the volume limit way down and then boosting the volume itself up to max should expand the lower dB range but it really doesn't for some reason.

I'm also going to try out a visual approach in addition to the compressor (bear with me here), which would let me "see" the subtle changes without having to eliminate all the upper volume ranges just to hear the lower ones, like with audio compression. The old style detectors with the little analog needle are interesting to use because you can actually see a target wiggle the needle that is not discernable in the speaker due to the non-linearity of human hearing and our inability to really pick out the differences between subtle changes in volume (hence the logarithmic decibel scale, etc).

Anyways, looking forward to seeing how your project progresses.

It surprises me a bit that you blokes who have been searching for serious gold and will spend 10,000 dollars on the ants pants of gold detector but don't spend a few bucks on something that will ID heavy deep iron  gold field relics.
A magnetic compass, a Dip Needle, almost any non motion vlf t/r discriminator with push button tune rest,(used in reverse disc mode) a Garrett Scorpion, a second hand Infinium, a strong magnet on a string........This stuff can save a lot of unnecessary digging.............But then again that deep iron tone might be coming from a buried stage coach strong box chockers with gold bullion. ....So yeah, forget all that other stuff and Dig It All.

Hi Jason,
                 I enjoy reading your posts, they are very catalytic in that they get one thinking about new possibilities. You seem to have a fresh perspective on things, keep it up and don't let apathy stifle your meditations.

I'm cheating and using the old SA571. I'm rehashing a circuit I made for my Eureka Gold, another Minelab machine that was less endowed in the audio department.

With my compressor installed the gold tally and deep shotgun pellets went up exponentially.

I'm using a couple of LiFePO4 cells in an AA package which I believe have a protection circuit that kicks in too late, so an 8 pin micro injects a little ditty every 30 seconds when they near an end-point I feel is more appropriate to longevity.

After the 571 I have a MC34119 low voltage differential driver audio amp.

If the results are good I may even attempt a soft solution on a dsPIC instead of the 571.

What gets me is the 4500 has really good audio with a super limiter. I could tweak that machine much more than the 7000. Going back to the 4500 occasionally has been a boon as I am used to the talkative 7 so cranking the 45 up has produced some nice pieces.

My first detector was a Ground Hog and I remember how I relied a lot on what that needle was indicating. It might be interesting to convert that needle into a 3d graphical histogram that alters shape and color depending upon travel direction, acceleration magnitude, and historicity. Expressed on an OLED display fine details could be added to emphasize target response characteristics.

See what you do to people, I don't have time to explore this and it's so frustrating life is so short.

HH.

Prototype 7k compressor

Sharp board! Do you have a place make them from schematics or do them yourself? SMT components even, nice.  I'm just an amateur tinkerer, your stuff is way better than my rats nests of junk I make on perfboards.  

There are some interesting microcontroller developments lately making software solutions compelling, have you seen the Raspberry PI Zero? It's an entire computer half the size of a credit card with analog and digital inputs for $5.... Some interesting times coming in the future. I've done a bit with old 8 bit PICs but I haven't tried out the dsPICs yet, they look powerful though.

I agree with the 4500 audio too. For cleaning patches I would use the audio processing as a compressor of sorts. I tried explaining the concept to a few people in the field and it just wasn't chooching so I was going to make a video on how to do it with the GPZ earlier this year and discovered it wasn't working the same. So thought I'd make a hardware compressor to do it instead, and glad to see I'm not the only one thinking along those lines!

Anyways, looking forward to updates on your project. The one question I have is wether the GPZ audio is digital or analog. Because with digital the signal may just dissapear at some point no matter how much the lower dB range is expanded. But with analog audio as long as the noise floor is low enough and we have enough amplification then in theory we can just keep expanding and zooming in on the little mouse squeeks. Am I thinking about that right?