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Making A Patch Lead For Gpz7000

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There is a guy called Eric Foster who did a lot of work on PI detector before Mine Lab got on the seen. He did a very informative report on coil sizes and their response on targets including their depth and size. Although coil and detector have improve since then the ratio still works. If you Google “Eric Foster + Coils” you might find some good knowledge.  

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20 hours ago, jasong said:

Don't forget that when I go prospecting I have a 2000 mile round trip, it's a significant expenditure for me and requires a lot of time off which means I'm not getting a paycheck at work during that time either. The only way I can go detecting is if I make it pay for me. So, I might approach prospecting differently than a lot of other people here. The 12" and 17" coils are coils I can see paying for me or a person with an approach like mine.

Here's why...

Brilliant post Jason. There are many strategies to consider when prospecting, and your post beautifully illustrates the fallacy of thinking any one coil or detector is going to suit everyone in a similar fashion. We all have vastly differing circumstances and trying to declare any one setup “the best” for people is an exercise in futility. For one person it’s a PI with a large coil. For another it’s a hot VLF with a small coil. Either can be the best choice depending on the situation.

For my part I have found that I find what I look for. If I’m geared up for small gold that’s what I find. If I gear up for larger gold that’s what I find. As a rough rule, anyone trying to make prospecting pay is better off going for the larger stuff, but you have to go where the larger gold exists. Yet many only have time to access locations with tiny gold, so that works better for them. Chasing larger gold also often means long stretches with no gold, and most honesty don’t have the patience or time to ride it out. Chasing small gold at least has a better chance of finding something each time out. But it rarely adds up to much as far as weight but it’s fun.

There are a lot more factors that go into the prospecting calculator than most casual folks ever consider.

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In my GPX days I always used larger coils, either an 18” round monoloop or a 17” elliptical (after market of course). Because of this I traded off the small gold in the sub gram range. During testing of the GPZ I very quickly discovered the GPZ14 coil was easily out performing the 18” mono on my GPX with many deep nugget digs in the multi ounce range being checked and cross checked where the GPX was producing nill signal or minimal signals. As such the GPZ14 coil is now my go to coil for the GPZ and accordingly my small gold take has increased dramatically because the GPZ also shows a marked improvement on small gold compared to the GPX with small coils attached. The reason the GPZ14 hits the sweet spot is three fold, it has very good depth, its weight is OK and it produces a LOT less salt signal than the GPZ19!

The thing about GPZ is it requires careful coil control to manifest deeper target responses, this is when ‘any’ target is right on the edge of detection regardless of size, as such the weight of the GPZ, assuming you are rigging it up correctly, actually assists in the control needed to get DOD coils to create a recognisable signal by having a consistent range of motion over the target. 

I have found the X coils due to their lower weight relative to size can be quite beneficial, as an example the 17 “x 15” one I have used is very much akin to the old 18” monoloops I used to use on the GPX machines. It’s just a shame I cannot actively use the General Gold modes to take advantage of the extra thump on larger gold because of knock sensitivity. However is quieter soils High Yield goes OK.

The X coils can have a more mono like signal response compared to a traditional wound DOD coil, that and the lighter weight and different size options explains why those reporting have been enjoying them so much, especially the smaller variants. 

The biggest fear is the patch lead failing and possibly bricking your machine, its an expensive exercise getting the GPZ fixed.



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The quote I got from Minelab AU was close to 3000.00 to repair the smoked circuit boards.

But hey, it’s only money right????

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21 hours ago, jasong said:

Here's why: I look at each coil I use relative to another coil. If I plot depths vs weights for the same nuggets on different coils, I end up with something (very roughly) like the following graph. Units are arbitrary.





I can't argue with that, Jason.  Those spiral wound coils really seem to be rocking it.  I am a visual person and seeing the graph is a great way to plan out your target weapon for the trip.  Out of curiosity, how did the 17" coil fair in the graphs?

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4 hours ago, Steve Herschbach said:

Brilliant post Jason.

Yes, I second that. ? Awesome Jasong & thank you for the effort of putting all that together & getting that across. I am lucky both with our insanely mild ground & that gold is literally all around me where I live & I dont depend on having to find a certain amount at any given time to make it have to pay. Albeit that the bigger bits are long gone. I absolutely get your point.

Very best of luck to you out there.

JW ?

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There are too many variables to determine fault on the blown detector...at this point to paraphrase Mark Hyde...

you can fix the blame or you can fix the problem...

I am sure there are plenty to blame but only one way to fix the problem...

very sad as 3000 bucks is a very big mistake!


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Figure I have heard for a circuit board blown due to this sort of thing is indeed thousands of dollars, not hundreds of dollars. And it will not be a warranty thing no matter who does it. Is anyone who makes one of these leads for somebody going to pay up when a $2000-$3000 bill comes due? You can say no warranty and at your own risk, but this is the sort of thing that causes lawsuits as there is too much money on the line. And nobody ever need be right to file suit. Simply fighting it and winning costs money. From a guy very well versed in all that who has been down that road in business I cannot overstate enough how much all involved here are playing with fire to a certain degree. The risks involved for anyone making one of these patch leads for somebody else is very high and even recommending such... I'm not going there. Just a word to the wise. I am all for sharing information, but I am for the umpteenth time mentioning that I take no responsibility for any of the information posted here by anyone. I have no way of knowing what information may or may not be correct and what hints or tips could lead to failure.

Having said that, if anything posted is known to be information that would cause a direct failure, somebody please let me know and I will delete it.

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