Jonathan Porter

Steve I for one am looking forward to your insights on the use of the inbuilt GPS of the GPZ 7000.

Paranoia is situation normal with gold finders, especially with their hard won nugget patch info, but like you said the odds of someone actually hacking and then collating the data are extremely small. To my mind the biggest risk would be friends and associates loaning or having access to your detector, at the end of the day it comes down to plain old common sense.

JP

Hi Steve definitely was not trying to criticize, and your methods are sound. I was just wanting to impart some of my experiences on undug targets that proved to me there are aspects of General that need to be taken into consideration if maximum depth is sought on larger targets.

For the record I spend most of my time in High Yield too because that provides me with a steady income stream while I patiently wait for a larger coil to become available, then General will be getting a thorough work out.

JP

On 6/9/2015 at 8:13 PM, Steve Herschbach said:

.........High Yield is best on one ounce and smaller nuggets. General is better on nuggets weighing several ounces or more. I am pretty confidant I will hit them anyway. 

Steve I've seen larger than ounce pieces give poor responses in the High Yield modes so it pays to go over the deeper sections in General to be sure a big piece is not lurking there somewhere, especially the more solid type gold.

The Gold modes will liven targets up differently, High Yield is brilliant on disseminated gold and nuggets from around an ounce but more particularly around the 10 gram mark and down. General is the best outright depth on larger than 1/2 ounce right through to mega size unless the target signal is very fast time constant (specimen or irregularly shaped gold). There is also a corresponding increase in ground signal with the use of High Yield which can counteract the response of very deep targets.

JP

Hey Chris, its great to see you out and about doing what you do best. Can't wait to see how you go with the GPZ.

JP

Salt should not be confused with Saturable ground, they are different but sometimes are together in the one place such as in WA where the ironstone is prolific in the salty areas. Lifting the coil will not assist a real lot with strong salt signals (you can hear the salt signal right up to waist height), so it is much better to just slow the sweep speed down and use a Gold mode that is less impacted by it, going from High Yield to General to Extra Deep or Severe. 

Severe was developed for highly saturable ground types not salty ground but it does help a little.

Hope this helps,

JP

Crow is code for "Minelab does it again"... well done on the lump Klunker. Every individual target is unique to the Tx and Rx of the GPZ, some excite it no end others less so but overall there is definitely an advantage over previous tech. Discovering the GPZ edge can be an individual experience dependent a lot of times on your particular level of skepticism.

Have a little faith people, Minelab are leaders in their field for a reason.....the GPZ 7000 is very much part of that story.

JP

There are real advantages to being the first bloke on the ground with new technology!

Steve just for the record and to avoid any misunderstandings, I was the first guy on my OWN ground not anyone else's.

JP

A picture is always worth a lot of words, this nugget was 2 1/2 ounces at a measured 2 1/2 feet. I tried every timing configuration possible on the GPX 5000 including Sharp with a 20" monoloop coil and could get zero response. The GPZ with 14" Super D coil could easily see this target in all Gold modes and Ground Type modes, in General Difficult I could lift the coil 5 to 8 inches above the target and still hear it.

JP

Have a video on Audio Smoothing up on the Minelab YouTube channel for those interested.

Hope this helps

JP

Prior thread in subject

My take this early in my use of the GPZ, it will balance out small nuggets. To prove this get a 0.5 grammer or smaller, and after half hour or so of using GPZ without touching the tracking, ie GPZ is GB for where you are, place small nugget on ground pump up and down over it and listen to the signal get fainter. I think it might have been JP who early in the piece advised setting the user configurable button to manual GB, I have done that and feel it is the way to go. I went through a very frustrating time on a patch of small pieces, (but fun) trying to locate once dug out, by setting the user button to manual GB getting piece then going back to auto tracking the GB setting the GPZ had reached before going to manual GB seems to be not affected.

But I stress this is my take, it is early days.

JP

http://youtu.be/2Qf_MUQKyjo

Worthy of printing out and keeping in the truck, good explanation.

 

One question I have is during the initial startup phase when you only see the Minelab logo on the screen, is the detector actively sensing ground information and calibrating itself? Or does that only begin once the threshold becomes audible and the modes/options screen comes up?

Detector has a lot of initializing to do before transmission begins, if interested have another detector nearby and listen to its audio at switch on, once interference begins you will know at what point the unit is live.

JP

In the past I've sold a lot of large pieces to an Australian buyer at spot because he will eventually donate to a museum, nuggets sizes ranged from 20 ounces through to 83 ounces. Otherwise unless the piece is beautiful or jewelry quality into the melting pot it goes to fund the next prospecting trip.

Seems harsh but I made a decision long ago that the lifestyle was of more value to me than the bragging rights of still having the gold sitting in the dark in a bank vault somewhere. 

JP

On 4/6/2015 at 9:35 AM, Steve Herschbach said:

The Minelab GPZ 7000 audio Smoothing function was directly derived from the Stabilizer control used on the GPX series. From JP at http://www.detectorprospector.com/forum/topic/715-gold-i-found-in-victoria-with-the-gpz/?p=6424

"On the subject of Audio Smoothing: Off on the GPZ = 20 on the GPX 5000, Low equals 15 and High equals 10."

JP at the link referenced obviously prefers Smoothing to be left off.

My public comments always come from what I feel are a basis of solid field experience, in the case of Audio Smoothing it has come from many hours of discussions with Bruce Candy and Minelab's PD team, if Bruce tells me a way to get maximum performance out of his technologies then I'm all ears because in this particular case it was Bruce.

JP

PS Upon reflection, a tip for people reading the methods described when using Audio Smoothing as a ground controlling tool.

Audio Smoothing is a filter and as such will filter out a certain amount of ground signal as well as a lot of the target signal especially the deep faint targets, hence if you can tame the ground signal somewhat in ground that is not too mineralised then you can continue detecting in a Normal Ground type mode instead of reverting to Difficult.

Difficult Ground Type removes ground signal and at the same time also removes target signal responses as well, so in less aggressive ground types, such as is in the US, using the Audio Smoothing as a ground signal filter when using Normal Gold Type mode makes sense, however keep in mind the operator needs to get the Volume levels correct to save on retraining their ears to the volume level differences between OFF and High, because although it sounds great going higher on the Smoothing it will be painful coming back again!!

A sad day and a big loss to the very rich history of metal detecting.

Condolences to his family and friends.

JP 

Is there any chance these two guys could come on the forum and do a question/answer session about some technical aspects of the detector and settings?

 

In particular some kind of clarification on General mode would be great. From Minelab various sources we've now heard "5+ grams", then "medium to large", then now "a few ounces" regarding the point where General should be used over High Yield.

 

I understand every nugget is different and it's very difficult to quantify these sorts of things (the White Paper scatter plot data point spreads as a good example). But this 5g, medium to large, and a few ounces defintion is far to vague and broad for me to get any kind of meaning out of it.

 

But even in the white paper it seems that on average even on larger nuggets that High Yield is still outperforming General, or at least staying up with it despite wether the 5000 was in Normal or Fine Gold.

 

Since Phil comments in the video that General is "pushing the technology to it's limits" I am trying to understand this, seems like we should see something more definitive in the results.

 

Also, I'd be very curious to hear wether there will be the ability to add on via software updates, additional timings or other features into the programming. A slider for audio smoothing comes to mind. I have a whole slew of them which aren't really relevant to this gold mode thread but I'd love to ask.

Phil is right about pushing the envelope with the General Gold mode both in Normal and Difficult, the Go To mode for outright GPZ performance is General. However the Go To mode for the regular finding of gold with the GPZ 7000 will be the High Yield Gold mode as it livens up those nuggets that previous PI machines have missed especially the Fast Time Constant ones, those nugget sizes are more plentiful so will be targeted more often.

High Yield offers up superior performance on nuggets up to 15 grams or finely disseminated gold specimens or roughly shaped nuggets, this is very dependent on ground signal response as High Yield can generate more target masking ground noise especially in the Normal Ground Type mode. The sweet spot for High Yield/Difficult compared to General/Difficult for nuggets at depth is around the 8 to 10 gram mark with a marked increase in signal strength, however generally, everything from that size down using High Yield has a much stronger signal strength but obliviously depth decreases proportionally as the size decreases.

In a nut shell, each and every target is unique to the transmit/receive of the GPZ particularly when using High Yield, however if you want outright performance/depth on larger gold sizes then General is the far better option, this also will become more apparent when a larger coil becomes available.

JP

I agree the naming of Extra Deep is confusing, Extra Deep will come into vogue when a larger coil becomes available. The mode has similar performance on large nuggets at depth to General but has less sensitivity to small gold and consequently also has less sensitivity to close to coil ground signal responses. This would suggest it goes "Extra Deep" on the larger pieces, especially in problematic ground where the saturation signal could mask a good target.

Hope this helps,

JP

The two guys in the video are good friends of mine who are very passionate about metal detectors. Mark Lawrie on the right has spent considerable time with me in the field over the last few years and has found his fair share of nuggets along the way, Phil on the left is scarily bright (both guys are inhuman in this regard compared to my simple two dimensional brain), Phil did the main development work on the Gold Modes and also the Ground Balance Tracker, both of which still blow me away on how refined they are . I personally feel the Product Development guys having a say on the GPZ is a great idea as it gives people a further insight into the detector from the developers point of view, sure its a little stilted but the overall message is still extremely valid.

Putting anyone in front of a camera is daunting at the best of times, having them do it unscripted is testament to the amount of passion they have for the GPZ 7000.

JP

 I might have discovered something useful this weekend. There are globs (Technical geologic term) of hot ground where I was detecting that are easily confused with a very deep large target, even after digging several inches. Also the roots of large trees give a signal that tend to make you start digging and wasting time. A few passes over the these with a forward-back motion greatly reduces or eliminates these signals. I experimented with this enough to be confident that good targets are not being balanced out. I'll go dig up a few multi-ounce nuggets next time I'm out just to be sure.

Klunker you have "discovered" a good technique, tree roots only signal as the windings are exposed gradually through a side to side motion, I'm pretty certain it is caused by one winding being over or near the root and the other not being over the root, and the coil is reacting to the wet sappy section of the plant (they draw up mineralised water in the gold fields, and therefore are conductive). By approaching with the front of the coil in a push fashion you have exposed both tips of the receive windings to the target and learned it is most likely not a good target.

Be careful however because if it is a deep large nugget then the middle of the coil needs to be exposed to get a good response, the Super D coil has to be right over the top of a target to get the best depth possible, it is NOT like a Monoloop coil in that respect. However both windings will respond to a deep target when swept from left to right, whereas the tree root will only be reacting to first approaching  winding not both.

JP

Thanks Steve 

I thought that the Z may have been smart enough to retain its GB when changing between ground modes 

But like you said 20 sec's and your done , my mate and I have been using the 2300 as a pinpointer , the Z finds a target I steak a yellow tent peg in its location and move on to the next target while he Digs and checks the targets . how lucky em I to have a "Dig Bitch" cant wait to find a super deep target that will sort him out 

 

We also found that using a pinpointer is well worth using these days 

 

Cheers Marty

The GPZ remembers its GB position when you go from one gold mode to another, however from a fresh power on state you need to perform the GB procedure as described in the White Paper to be sure the GB is accurate, this procedure is recommended for every Gold mode you intend to use in that session. 

JP

I would not want to hazard too much of a guess on whats happened there, highly unlikely it was a good target unless he hit the Quick Trak. Could be the GB was out from a bad start up balance and then finally got enough info to get rid of the signal, but even then it sounded pretty positive.

Best suggestion would be to power cycle the unit or even do a re-set all then detect around the area for a while before coming in over the target again, when committing to dig suggest they fix the GB first. 

JP

I think the WM 12 might work with the CTX 3030 though, as in its backwards compatible, but I've not tired it to find out.

JP

Makes me wonder why this didn't comenout with the owners manual. And with this technical paper, there is not much need for the manual. Except for the mapping aspect.

Believe it or not, the biggest problems I've seen with people with the GPZ 7000 are experienced GPX users, those who follow the manual and don't try to GPX the GPZ are fine. The animation Guide on the detector start screen clearly shows the method required, Bruce's White Paper just explains more succinctly the reasons behind it and some very helpful tips on getting that process down pat.

JP

Steves right, there is nothing wrong with turning off and on again any time you like or just using the Quick Trak button whenever you feel the need. However I have seen some instances here in Australia where the GB has been messed up (particularly in the variable mineralised areas and more especially with people pumping the coil at the start of a session), follow the recommended work flow procedure and all is good.

Work Flow:

Turn unit on, do an auto tune and manual tweak if threshold is unstable, with coil held in air and away from metal objects confirm settings are to your liking (Threshold, Gold Mode, Ground Type, Tone etc), select an area typical of your chosen location without trash targets, then with coil held at detection height above ground hold the Quick Trak button in and walk steadily away swinging the coil evenly, after 10 to 12 seconds (listen to the audio during this time and you will hear the unit stabilize) you can release the Quick Trak button.

This method is extremely simple to do and should add near zero time to your normal routine, exposing the coil evenly to as much typical ground as possible in that time frame helps immensely with the GB averaging. 

Edit addition: Please keep in mind, the detector dumps all the collated data at switch off except for the last setting which should be the best anyway, so when you switch back on again you are starting at a very refined position for your chosen area. As Steve has mentioned, in practice most people should not even notice the differences from one session to another unless they go to ground that is very different from last switch off.

JP