Relic Hunting With The GPX 6000?

[George Kinsey]

Does the GPX 6000 signal on small near surface iron? I want to test it at colonial and civil war sites to relic hunt. If it does what sort of signal sound does it produce? Thanks

[Steve Herschbach]

Yes, the GPX 6000 will find slivers of steel you never thought a metal detector could find. And small birdshot you never knew existed before with other PI detectors, even the SDC 2300. It’s specialty is small stuff. Way more sensitive than a GPX 5000 to tiny ferrous, no discrimination except tones, I’d not consider the GPX 6000 much of an option for relic hunting. There is such a thing as too sensitive. The GPX 5000 is far better suited to that task in my opinion, due to far more sensitivity control options, an actual disc function, and the best set of coil options of any detector.

If using a GPX 6000 you can generally avoid digging small ferrous by digging only low tones, which indicates large/strong targets, or lifting the coil far enough off surface to miss the tiny stuff. Most small ferrous will give a high tone. It does have some other tone options I’ve personally found interesting, but they are dependent on the automatic ground setting, so results vary with the ground.

https://www.detectorprospector.com/forums/topic/16696-coin-and-relic-detecting-with-the-gpx-6000/

If you read that article, I was using a GPX 6000 to hunt effectively in an area heavily littered with ferrous, so it can be done, and I’d not write the machine off completely. Just don’t buy one specifically for the task unless you can run one for free first, as this is cutting edge stuff, and only certain people will take to it. Being able to effectively read the machines tones in your particular scenario is the key.

[George Kinsey]

Thanks Steve.

[Gerry in Idaho]

Steve said it quit well, the GPX-6000 is just to dang sensitive for the task you inquired.  Now for User Friendly PI detector that can handle higher mineralization than a VLF and is one of the best ergonomically built big machines out there with exceptional depth, its got it.  But me personally (Yes I have hunted CW Relics in TN, VA, GA and NC with a PI, I feel a used GP-3000, GP-3500, GPX-4500 or GPX-5000 is a better choice.  Best bang for the buck in the older GP series.  Good Luck.

[Jeff McClendon]

I have been experimenting with the GPX 6000 and relic/coin/jewelry hunting since it is too snowy and cold here to do much else and its fun. Basically, what I have found on wild digs and testing backs up what Steve H and Gerry have said already if one is using a Mono coil. The GPX 6000 with a Mono coil is incredible on tiny targets and will absolutely blow my head off for several seconds on larger targets. Using the 14" DD is a slightly different story however and that coil or other DD coils that might be aftermarket produced (PLEASE!!!!!) could make the GPX 6000 have even more relic/coin/jewelry possibilities due to less sensitivity and less elongated target responses. 

I have not by any means tested the GPX 6000 with a DD coil on enough mineralized sites to find out how much its automatic ground balance which can't be locked will change the low/high---high/low inversion point. So anything I say or show here is totally site specific to where I have been able to use it.

My results show that usually (iron is always an oddball) the inversion point is between 4 and 5 grams weight or 2 and 3 grams weight depending on coil type, soil timing and ground balance.

Here are some photos that it took me a while to find a pattern for so they are grouped like this: photos 1 and 2-Mono and DD (Cancel) coils using Normal with high/low target responses; photos 3 and 4-Mono and DD (Cancel) coils using Normal with low/high target responses; photos 5 and 6-Mono and DD(Cancel) coils using Difficult with high/low responses; and photos 7 and 8-Mono and DD(Cancel) coils using Difficult with low/high responses. 

Again, these are not definitive by any means. The sites tested are extremely iron mineralized to moderately iron mineralized. 

To me, these results show a clear advantage for the gold prospector if they want to identify big iron by using the GPX 6000 in Normal with either coil type, hunting by audio response (at least on my sites) and go for 5 or 3 gram and smaller gold. For a relic hunter, large caliber bullets and shell casing along with tiny iron and flat iron relics.....might be good using a DD in Difficult depending on trash levels at the site.

The photos are basically organized from the top.....iron/steel, aluminum, brass/lead, coins/jewelry.

Photo 1

 

Photo 2

 

Photo 3

 

Photo 4

 

Photo 5

 

Photo 6

 

Photo 7

 

 

Photo 8

[jasong]

It's similar for nuggets too, just as a general observation. The sluggy/solid nuggets in Normal in some medium/hot ground seems to invert around 2 grams. That's specifically on the gold and ground I'm hunting though, haven't really tested it elsewhere.

It makes for a nice little quasi-discriminator when you get in the ultra trashy places. The 7000 wasn't so reliable, I've found 1 oz'ers that were still high-lows on it, and so ended up digging it all pretty often.

Some days I have started ignoring the high-lows completely on the 6000 in really trashy spots, and just hunted for the quiet low-highs, and so far these days have paid better than digging all. Again, probably very site specific though.

[Jeff McClendon]

1 hour ago, jasong said:

It's similar for nuggets too, just as a general observation. The sluggy/solid nuggets in Normal in some medium/hot ground seems to invert around 2 grams. That's specifically on the gold and ground I'm hunting though, haven't really tested it elsewhere.

It makes for a nice little quasi-discriminator when you get in the ultra trashy places. The 7000 wasn't so reliable, I've found 1 oz'ers that were still high-lows on it, and so ended up digging it all pretty often.

Some days I have started ignoring the high-lows completely on the 6000 in really trashy spots, and just hunted for the quiet low-highs, and so far these days have paid better than digging all. Again, probably very site specific though.

That is basically the way I look at it too when prospecting for smaller gold. Depending on the site the inversion is somewhere between 2 and 5 grams. As long as I can hunt in Normal......avoiding big iron is not too hard to do if it is all over the site. If I have to hunt in Difficult so far anyway, it is basically dig it all with the 6000.