I am new here. Want to buy a GPZ 7000, but also want to wait until the next model of GPZ technology coming out. It would feel horrible to buy GPZ 7000, and new model come out in half a year.
So does anyone know or hear anything about when new GPZ metal detector will come out?
Thanks a great deal.
I am starting a thread on GPZ discrimination. In this missive I use “discrimination” with reference to both hot rock and junk identification.
Let me start with my hypothesis then describe how I got there. I am very much asking for corroborating or contradictory evidence to my hypothesis and other notes as well as any other useful info on GPZ 7000 discrimination.
Natural gold from small, barely perceptible signal return, to huge enough to provide overload, always produces a high-to-low tone when in high yield gold mode / general ground type settings. Natural Gold can sound either high-to-low or low-to-high in difficult or severe ground type settings. Ground type is the only user changeable setting that effects tone changes high-to-low or low-to-high on a particular target.
Required Conditions: negligible EMI, negligible other metal or overriding hot rock present.
The one thing that has been true to date in my field experience and experiments, is that every natural gold find or test nugget from small, barely perceptible to huge enough to provide overload, had a high-to-low tone when in high yield/general. I understand this hypothesis is no giant breakthrough enabling classification of the Zed as anything other than an all-metal machine as the Minelab manual and advertising clearly classify it. Nonetheless, it’s the entire useful conclusion I’ve come to in as few words I can make it. (I have trouble with writing few words. J ) Minelab makes no mention of discriminating sounds yet the pitch change of high-to-low or low-to-high is impossible to ignore, and naturally causes the curious to explore.*
Early in my experimentation and Zed education, I spent hours determining what controls affected a reliable pitch change in different junk materials and hot rocks and gold. All kinds of elaborate charts in my notebook. I am glad I have not posted on this topic earlier because I have been through many cycles where experiments and field experiences would give me some preliminary beliefs which would soon thereafter be disproved by another experiment or field experience.
What has emboldened me to make this post (as simple as the hypothesis is) is that I was fortunate recently to experiment on a very large gold in quartz specimen. Not certain on the mass of gold (> several ozs for sure) yet the return signal easily produces overload response on all gold type/ground type combinations. (No, not my gold. L ) The specimen produced high-to-low on high yield/general, low-to-high for difficult and severe ground types. Always true as I backed the Zed coil away from the specimen.
This was enlightening and counter to my early Zed experimentation on aluminum where size of aluminum changed pitch direction. I found that the Zed, with no change in settings, will respond high-to-low on small pieces of aluminum foil (several mm x several mm) yet respond low-to-high on large (>100 mm x >100 mm) keeping high yield/general constant as well as all other settings. Zed responds low-to-high on soda and beer cans with high yield/general. So, I have wandered about assuming the same for gold (size of metal can affect pitch change) and hence I have NO DISCRIMINATION at all. I “convinced” myself of this when I tested a 1 gram nugget (high-to-low) then a very large men’s gold wedding band (low-to-high) keeping high yield/general constant as well as all other settings. Hence my hypothesis states “natural gold” to distinguish from alloys.
Hot rocks, iron or mineral based, produce a symphonic range of return sounds and can be high-to-low or low-to-high on any ground type or gold mode setting. (another thread necessary on hot rock strategies.) My hypothesis of “Ground type is the only user changeable setting that effects tone changes high-to-low or low-to-high on a particular target.” is not in conflict with the fact that you can put audio smoothing on high and totally eliminate a return from a weak target. Audio smoothing setting does not change the pitch direction on a target.
Iron. Man made iron and high % iron alloy objects produce low-to-high on all ground types only if the iron is not rusted heavily. If the iron is rusted it can produce high-to-low or low-to-high. This of course is near useless info for the prospector because most all iron stuff we find is rusted.
Since I work in a hard rock environment, "dig it all" is just not practical. Hence, my experiments and documentation on the GPZ7000 tones to try and get any possible discrimination info out of it. In my environment, that mostly means hot rock. In my environment, I can prospect in high yield/general at least 90% of the time. Mineralization puts me in difficult or severe less than 10% of the time. I also have the “luxury” to mark interesting signal location first located by GPZ, then come back with my Whites MXT to try and discriminate. (Also have GMT, GB II and GB Pro available.) This works well on strong signals, or near-surface hot rock, however weaker GPZ signals produce inadequate response for any accurate discrimination from the VLFs.
Even if your environment requires you to mostly search in difficult or severe ground type settings, you could always go high yield/general as a discrimination test right over the target. Of course then you might have "overriding hot rock" condition. I think the most opportunity for uselessness of my hypothesis, even if it's accurate, is that I just don't have much experience of gold in difficult or sever ground environments whereas that is much the norm elsewhere.
* My previous Minelab experience is just ~ 80 hours with a GP3000, so I come to GPZ 7000 without much Minelab audio discrimination experience. I’m told on other posts in this forum that is a Zed education advantage.
By Steve Herschbach
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, but I do have to pop some bubbles here. Just because JP prefers to do something one way does not necessarily make it gospel. Sorry JP! The point being some people are experimenting with higher audio smoothing settings combined with either hotter Gold Mode settings or higher Sensitivity settings or both. I think this is a good thing so do not go thinking it is "wrong". There is no right or wrong per se, it is all about what works for each prospector and their personal tolerance for noise or the lack thereof. And believe it or not somebody might just teach JP a trick or two! Experimentation is good.
I thought it would be informative to copy what the GPZ manual (page 66) has to say about the Stabilizer control. Warning: the GPX Stabilizer control is backwards. The highest setting if 20 is the off position. Lower numbers increase smoothing. So the GPZ at off is same as GPX at 20 (off). Note that the GPZ High setting is the same as the GPX default setting of 10. The default for the GPZ 7000 is Low Smoothing which is the equivalent of a setting of 15 on the GPX.
One final note. RX Gain as referred to on the GPX is the same as the Sensitivity control on the GPX.
From the GPX manual:
I guess I should say that my preferences tend to follow JPs - I run with audio Smoothing off under nearly all circumstances. But I wanted to make this post to create a thread on the subject as it is very clear people are having success with other ways of thinking and again, I like out of box thinking. Lunks settings at http://www.detectorprospector.com/forum/topic/830-lunks-zed-settings/ are at the other end of the spectrum. I also liked Jason's observation on the subject at http://www.detectorprospector.com/forum/topic/827-minelab-video-gpz-7000-ground-type/?p=8276