Jump to content

Zed Scores Big On Civil War Relics


Recommended Posts

Sorry if this is a little off topic, but I thought this might be interesting to the GPZ owners/prospective owners out there. There is an event held in Virginia several times a year called "Digging in Virginia" (DIV), and the dealer I bought my Zed from is involved in the hunt this year (Keith Leppert of Fort Bedford Detectors.) Anyway, an area scoured with the GPX series was scanned by Keith, and he found a large number of additional civil war bullets with the GPZ, at much greater depth. Here is a link to a blog with the results:

http://detectingsaxapahaw.blogspot.com/2015/03/div-blog-day-3-going-deep-with-zed.html

And a link to the DIV postings:

http://www.mytreasurespot.com/main/read.php?5,650501,650501#msg-650501

Best,

Bob

Link to comment
Share on other sites


Hi Bob,

Not off topic at all, as it says in the forum header "A forum dedicated to prospecting for gold and other precious items using metal detectors, suction dredges, sluice boxes, gold pans, and more. Metal detecting for coins, jewelry, relics, meteorites, etc."

I am vitally interested in your links because there is a huge overlap in what relic hunters in very mineralized ground are doing and what prospectors are doing. It is all about max depth in bad ground, and relic hunters back east have discovered what prospectors have known for a long time - nothing can match a good pulse induction for depth. Until now with the new GPZ.

I knew the GPZ had the power, but what I have been wondering about is the issue with it being so hot on small stuff. This is generally good for prospectors, but I thought maybe it would be a real problem for the relic hunters and tiny surface trash. I wonder if the Extra Deep mode might ignore that small surface trash while still punching deep on those bullets, etc.

It looks like the GPZ once again proves it packs the punch. If people can deal with the trash issue it may be the next big thing in relic hunting, especially at DIV. The bottom line is that wherever good finds exist somebody is eventually going to put a GPZ on it, even if it means digging all the junk. Thanks for posting as I will be following it all with interest.

Link to comment
Share on other sites

I think the Extra Deep setting needs to be explained more. From what I've heard. It really does nothing. Just a marketing ploy. But there got to be more than that to it. If in a trashy area, and you know there is deeper gold. Why wouldn't this be a viable option?

  • Like 1
Link to comment
Share on other sites

Reading the Aussie forums again?

High Yield is the loose equivalent of a short pulse delay timing. Very hot. General would be a longer delay type setting, less hot on tiny stuff but allows for clearer signals on medium gold. Extra Deep would be the equivalent of a long pulse delay setting only for very large targets but gives up a lot on the smaller stuff. Not a good mode for general gold prospecting, but may be good for dialing down the sensitivity for small surface trash and so useful in really trashy locations or for relic hunting. Or for looking for that really big deep nugget people are convinced they are going to find.

50 grams may as well say a couple ounces. If you are hunting 2 oz plus nuggets this is the mode to go with in theory. I doubt Minelab made it up as a marketing ploy. If they say it will punch deeper than the other modes, it probably will. But only on massive targets.

Extra Deep may or may not give up depth on those big bullets. Even a bit of lost depth may be ok if tiny surface stuff can be ignored. Definitely a setting I will be experimenting with more.

minelab-gpz-7000-gold-ground-settings.jpg

  • Like 1
Link to comment
Share on other sites

Thanks for the feedback and additional comparisons on settings Steve. Yes, there is a correlation in ground type between Virginia and the West (to some degree) more so when you look at the heavier mineralization around some of the old mining areas in VA. I am interested in both the relic hunting and the prospecting, so the GPZ is a great machine from this standpoint.

As you pointed out, the challenge is the heavy trash. The GPX at least had the iron discrimination to some degree, but GPZ has none. I have seen at least one article from the Aussie side that talks about using the tones on the GPZ to differentiate between gold and iron in a heavy trash area, that the surface trash is giving a quick sharp tone, where underlying co-located nuggets are giving more of the warbling tone, so there seems to be some way to distinguish. As of yet, I have not been out enough with the GPZ to pick up on this subtle difference in tones in a trashy area. 

The good news for the DIV crowd is that many of the areas where they are hunting have been pounded with VLF and PI machines, so the GPZ is mostly working in "clean" ground. The result, as seen in the article I posted, is greater depth over a range of GPX coils with the stock GPZ coil. This should "open up the relic fields." too.

I'll post more from the east as I get out and learn the GPZ.

Bob

Link to comment
Share on other sites

Quote
Definitely a setting I will be experimenting with more.

I was thinking the same thing, so I recently acquired a lead bar, 13.5 ounces troy, a troy pound and then some, and not owning any pound sized nuggets myself, I figure its the perfect stunt double for that really large nugget for testing the performance of the GPZ. Good for testing and experimentation.

I am figuring extra deep is not for bullet sized targets, but for large brass belt buckle sized targets.

Link to comment
Share on other sites

Interesting to see the Z working in a different capacity. I'm not much a relic hunter (mostly because I live in an area with very sparse older history) but interesting to read about it and see some results, thanks.

For whatever it's worth (about 2 cents and no more) my experience is the warbling is more related to geometry of the target and depth than composition. But maybe my ear just isn't trained enough yet. At least, I've been digging a few teeny tiny bits and they all sound different and I would have missed a couple nuggets going off sound only as some are nice and sharp and others sounded like a piece of tiny rusty iron wire.

I have been testing a 47 gram melted slug of gold since it's the biggest gold target I have. Granted it's air tests with a meter stick since the odds of me finding a deep buried giant nugget to casually test in real world conditions are about zero haha. But anyways, I can't get General to outperform High Yield on depth with it. I can get a diggable signal at 23.5 to 24 inches with the sens at 14 on HY and the best I can squeeze out of General is 23, and maaaaaybe 23.5. I haven't tried extra deep yet. Anyone else had luck with getting general to outperform HY?

Link to comment
Share on other sites

I would not expect General to outperform High Yield on air tests myself. That is sort of like air testing a high frequency Gold Bug 2 against a lower frequency detector. The Gold Bug 2 wins the air test and loses the in ground test. It is the performance in ground relative to the ground mineralization that makes all the difference in the world.

Link to comment
Share on other sites

post-1-0-06032700-1426522544.jpg

Figure 2 shows a comparison between the ZVT VRM soil signal and the nearest equivalent PI soil VRM signal; both transmitted magnetic signals being bi‐polar, with the same fundamental frequency and same rapid change of magnetic field period. It should be noted that the PI receive period is half that of the ZVT period, because the PI system shown in figure 2 transmits for half the time and receives for the other half of the time, unlike ZVT that transmits and receives simultaneously just about all of the time. The important difference in the VRM signals is that the PI signal decays away substantially faster than the ZVT system. This indicates that the receive signal for PI is less sensitive to longer Time Constant (TC) components compared to shorter TC targets than ZVT, and this is one of the main reasons why ZVT technology is better at detecting large nuggets compared to PI; another main reason being from the double length receive period in ZVT compared to PI for the same fundamental frequency.

Link to comment
Share on other sites

The somewhat humorously ironic thing is that it's becoming kind of difficult to test these things in ground. Digging a 3ft deep hole in concrete like clay to test some targets is something I gotta be in the mood for I guess. Most the ground I'm detecting bottoms out to bedrock around 1.5 to 2ft.

I'd be interested to see other people's results if anyone does some testing though. I did some "smallness limit" tests with all 3 detecting and ground modes when I first started and they were in ground to see if I could selectively ignore certain sizes of trash, but I feel like with more experience now I have to redo them.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...