Minelab Video - GPZ 7000 Gold Mode

[Jonathan Porter]

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

[Steve Herschbach]

The main problem is trying to equate the weight of a nugget with the time constant of a nugget. People want to think in terms of weight ranges when metal detectors do not detect weight. The correlation between time constant and weight is loose at best. A large specimen with ounces of dispersed low purity gold will be much harder to detect than a solid lump of purer gold weighing half as much.