Small Nuggets Vs Big Nuggets

[wanderer]

Maybe this is a dumb question  wit regard to PI machines  why is that one machine will excel at small nuggets but can't do so well on bigger nuggets.,  Doesn't make sense to me.  It would seem logical that iit can find small stuff  big stuff should be easy?

[DigsAlot]

I am sure there are threads on this subject. Good news is, Steve will pass by soon and may have the links. He is good about that.

Wait till you find some nugs don' even show up lol.

[phoenix]

7 hours ago, wanderer said:

Doesn't make sense to me.  It would seem logical that iit can find small stuff  big stuff should be easy?

This is my understanding of why one detector will get bigger deeper gold over another.
   A detector transmits a signal into the ground and then switches  to receive the signal coming back to the detector. Think of a opening and closing gate.  The longer the gate is open the further into the ground the signal will travel before the detector switches over to receive the signal. With the likes of the sdc2300 the gate opens and closes very quickly, doesn`t travel into the ground very far, so with the high frequency switching, it will find way more small gold than most other PI`s.  The slower switching detectors, the signal goes way deeper into the ground where there might be a bigger deeper bit.
   I hope I`ve got that right. Please correct me if I am wrong. Dave

[fredmason]

It is simple...if one machine could get it all you would not buy two, or three...etc

I think my GPZ covers most of the ground very well...just teasing a little bit on the above.

fred

[Norvic]

Gotta agree Fred, the Z to me is the detector that comes closest to getting all sizes, specimens, deep, shallow, the works. Of course not right down to those specks the GB2 and now the Monster vacuum. 

[wanderer]

This all started because i read Steves comparison of the Garret atx to the GPZ 5000.  I was figuring a small nuggets at a gram or less but it is all relative. So why doesn't some one build a  machine that alternates the Gate open close time the way phoenix describes it   cycle on and off  or even better do both simultaneously.  I mean we can build build computers that calculate millions of  data bites is fractions of seconds. We are already bulding robots  that can run  jump walk and move boxes ( see boston robotics and think terminator). is it really that hard?

[strick]

22 hours ago, wanderer said:

Doesn't make sense to me.  It would seem logical that iit can find small stuff  big stuff should be easy?

You would think...but this is more complicated then it seems. We have three different types of detectors VLF, PI and then there is the ZED 7000.  Ground mineralization is a key player. An engineer  would be better suited to answer this question but I'm thinking non of us layman would even begin to understand what they were talking about. 

strick

[Northeast]

15 hours ago, wanderer said:

So why doesn't some one build a  machine that alternates the Gate open close time the way phoenix describes it   cycle on and off  or even better do both simultaneously.  

Wanderer, I'm not a techy sort of person but my understanding is that the different 'timings' on PI detectors is exactly what you describe - different rates of firing off those impulses.  Fine gold, normal, enhanced and whatever the rest are just variations of each other.  

Steve or JP could definitely give you a better explanation but I think the different timings with different coils is the reason there is such a variation in what gold can be seen/unseen and what mineralization the detector can/cannot cope with. 

Hopefully that is somewhere near correct 

[phoenix]

15 hours ago, phrunt said:

I will most certainly bring it along next time you want to go for a prospect as I'm very interested to see if your GPZ will see it as I'm completely puzzled why my GPX can't see it, no matter how hard I try, what settings or coil I use, it's invisible even touching the coil.

I`ve got a speci I found maybe 30 yrs ago with a Whites GoldMaster that sg`s at 13 grams gold, I don`t believe there`s 13 grams in it but that`s what it sg`s at. Even though there is gold clearley visible, my GPX4000 cannot hear it, a gpx4500 cannot hear it and the GPX5000 can just barely hear it with a 8" Commander.  None of the new flat wound coils on the 5000 can hear it.   Both my 7000 and 2300 can hear it at 6 or 7 inches.     I expect JW will be able to hear your nugget no worries with his 7000.       cheers Dave