Welcome! Log In Create A New Profile

Advanced

In many ways I agree, however, not totally. Here's why.

February 18, 2020 08:56AM avatar
Quote
WM6
Great efforts .... but...

All VLF detectors (in contrast to PI detectors), no matter of brand, perform differently
in such primary air tests than in (near to real) soil tests.
First, let's look at the two types of detectors you refer to, the PI or Pulse-Induction and the VLF, which are actually TR or Transmit-Receive principle an might work in the VLF or LF frequency ranges. They work differently.

Second, "air tests' can be done with any type detector to get an idea of what their best performance might be if everything is in their favor, and it is an 'ideal condition'. Any difference, such as the mineralization texture and make-up as you mention, is likely to make a difference.

Third, the purpose is to evaluate potential performance for 'unmasking' ability to locate a non-ferrous target in an Iron Contaminated environment. I don't think we have any PI's that can "unmask" a copper or silver or mixed-metal coin in a close relationship to Iron trash. That's where some Discriminating TR's have an advantage.

Fourth, it is true the ground make-up needs to be addressed, but that really gets to be a study or discussion of the metal detector's circuitry design as well as the search coil size and type.


Quote
WM6
Main reasons: VLF detectors in such air tests are not proper ground balanced and detecting
does not imply to very important soil factors as soil resistance load and soil reactance (X) load.
True, but there's a problem here. Many metal detectors do NOT have an Automated Ground Balance or Manual Ground Balance control. Instead, they are factory preset internally, mainly 'in-circuitry', with some engineer's idea of what might be a good general-purpose GB setting and the consumer has no control. Sadly, I've found most of those detectors to have a much too-positive Ground Balance which results in a negative impact of overall performance.

For best ground-handling performance a user should have Manual GB control in the motion-based Discriminate search mode, and many, many popular models lack that capability. Let's not forget that a lot of detectors rely on a factory controlled / preset GB simply because way too many detector operators haven't got a clue how to make an adjustment for proper GB, or even know why it is important to consider it to handle the ground mineral make-up in the first place.


Quote
WM6
So to be with tests on real side of show, your target configuration need to be buried (dug in)
at least 5" to 6" under soil surface. More mineralized soil even better.
A... As mentioned, all these discussions are based on some of the trashiest locations you could imagine hunting here in the USA. It falls in the general category of Relic Hunting, but it could almost have its own category of Ghost Town Hunting, and most who have been involved in these tests and discussions are folks who go out on their own to search such sites, or better yet, they attended some of the past 11 Welcome-to-Hunt Outings which have mainly involved several old Ghost Town locations.

These places are especially littered with building rubble, a lot of sagebrush and weedy vegetation, and more trash metal than most could imagine. Torn-down structures and burned-down structures leave a lot o iron nails and screws and other ferrous and non-ferrous metal around, with the greatest amount being Nails. They have been lost or discarded in areas where wooden boxes of freight were opened, and for sure a lot of smaller Iron Nails used for shoeing animals, or building wagons, and the list is long.

B.. Naturally, there are going to be situations that would can 'reposition' a dropped or discarded Nail or Coin or Token or any metal object, such as: Plowing a field, horse or wagon travel on a road, trail or path. Cattle an horses moving about in a pasture or in and around a barn or shelter. Human foot traffic out to feed chickens, milk the cows, take care of other farm and homestead chores. Anywhere man, or animal or some sort of conveyance travelled can reposition a lost or desired target, as well as small annoying trash. And that gets even easier if the ground is wet, to very wet, from a lot of snow melt, rain, creek or river flooding, etc. when it is soft to muddy. It's especially worse around barns, enclosures, pastures and other grazing areas used by bigger and heavier critters.

There's no telling how deep some lost coins, tokens and artifacts might be as it is based upon ground conditions and activities that can move the soil and objects around to different levels when the ground is malleable and quite wet. However, there's some good news!

C.. In most of the places I have hunted for 55 years, unless there has been some deposition such as cut grass, fallen leaves and vegetation, or erosion or other natural acts that can leave a build-up over a desired target, or any of the activity that can also reposition the desired finds by human or animal traffic or plowing, most coins and other small desirable finds are located on the ground, just barely out-of-site, or can be toe-scuffed out of those locations at 3" or less. Occasionally a little deeper, but in undisturbed, unaltered, untraveled areas, they are not deep..

The Old Coins are relatively shallow and the discarded or lost Nails are also relatively shallow. The ground make-up can be a factor, but often there is so much trash that you can't find a clean, metal-free area to adjust the GB anyway, so I guess it helps that so many detectors are a fixed or regulated GB for the motion-based Discriminate modes anyway.

Coins and desired finds are mainly at shallower depths, so the main concern we have is finding them. That means selecting a detector and coil combination, and using the best settings we can tolerate, that will let us get a decent or good enough audio response for a non-ferrous target in the ferrous debris to investigate and make a recovery..

If the good targets and bad junk are co-located but at a deeper depth, such as your image suggested, that gets even more difficult for a detector to find the keeper target because iron has a greater effect on the EMF, and has a negative influence over the desired find as the coil-to-target depth increases.

I agree with what you're suggesting, but for the purposes we're discussing, 'depth' of any targets isn't the issue. I wish you were able to join us in June for our Welcome-to-Hunt Outing and experience some of the challenges we deal with.

Monte

"Your EYES ... the only 100% accurate form of Discrimination!"

Stinkwater Wells Trading Post
Metal Detector Evaluations and Product Reviews
monte@ahrps.org ... or ... monte@stinkwaterwells.com
503-481-8147
Detectors: I rely on an assortment of personal favorites I happen to like that work for me when and where I need them.
Pinpointers: Makro & Pulse-Dive .. Headphones: Killer B's 'Hornet' & 'Wasp' ... Detector Pro's Gray Ghost XP
Note: Detectors are listed alphabetically by Brand. Models are chosen based on search site conditions.
*** All working well today to make memories for tomorrow. ***
Subject Author Views Posted

Hopes & Dreams, squashed like a bug.

OregonGregg 125 February 16, 2020 05:04PM

Re: Hopes & Dreams, squashed like a bug.

Elbert 54 February 19, 2020 03:26PM

Re: Hopes & Dreams, squashed like a bug.

OregonGregg 54 February 19, 2020 04:01PM

Zincoln's Whites results...and a Compadre Attachments

zincoln 93 February 17, 2020 03:37PM

Just a few updates or corrections for Gregg's post.

Monte 104 February 17, 2020 05:36AM

Now you got me thinking...........

OregonGregg 84 February 17, 2020 08:52AM

There is still hope ............. Attachments

OregonGregg 80 February 17, 2020 06:06PM

Re: There is still hope .............

WM6 56 February 18, 2020 04:27AM

In many ways I agree, however, not totally. Here's why.

Monte 52 February 18, 2020 08:56AM

Re: There is still hope ............. Attachments

glabelle 86 February 18, 2020 08:26AM

That photo pretty well nails it. . . . . . . . . . so to speak. N/T

UtahRich 40 February 19, 2020 08:21AM

Re: There is still hope .............

WM6 55 February 18, 2020 11:26AM

Re: There is still hope ............. Attachments

glabelle 78 February 18, 2020 01:57PM

Re: There is still hope .............

WM6 43 February 18, 2020 03:50PM

thumbs upthumbs upthumbs up .. George, 'Thank You.' That photo even out-speaks me!eye popping smiley N/T

Monte 42 February 18, 2020 10:01AM

Re: There is still hope .............

glabelle 44 February 18, 2020 07:42AM

Re: There is still hope .............

glabelle 46 February 17, 2020 09:23PM

Yes, 'spreadsheets' fior OregonGregg.

Monte 51 February 18, 2020 03:34AM

Analytics for Gregg -

UtahRich 47 February 18, 2020 08:16AM

Another test suggestion

glabelle 62 February 17, 2020 09:11AM

Re: Another test suggestion

OregonGregg 54 February 17, 2020 09:21AM

Re: Just a few updates or corrections for Gregg's post.

glabelle 57 February 17, 2020 08:47AM

Re: Just a few updates or corrections for Gregg's post.

glabelle 71 February 17, 2020 07:27AM

Re: Just a few updates or corrections for Gregg's post.

Monte 63 February 17, 2020 01:17PM

Re: Just a few updates or corrections for Gregg's post.

glabelle 46 February 17, 2020 01:48PM

Deciding on a 'favorite' detector for Ghost Town Hunting? Simple ...

Monte 50 February 18, 2020 03:16AM

And some over-the-phone results.

Monte 68 February 17, 2020 06:45AM

Re: And some over-the-phone results.

diggindeep 61 February 17, 2020 09:11AM

Re: Hopes & Dreams, squashed like a bug.

Kickindirt 59 February 16, 2020 10:44PM

Coil size matters . . . . ???

UtahRich 50 February 17, 2020 11:54AM

Kickindirt, about the ORX and coils used.

Monte 73 February 17, 2020 04:45AM

Re: Kickindirt, about the ORX and coils used.

Kickindirt 57 February 17, 2020 06:04AM

Squashed like a bug?

UtahRich 66 February 16, 2020 10:29PM

Re: Hopes & Dreams, squashed like a bug.

diggindeep 74 February 16, 2020 07:48PM

I agree with you, but ....

Monte 76 February 17, 2020 03:43AM

Re: Hopes & Dreams, squashed like a bug.

D&P-OR 82 February 16, 2020 07:21PM

Del, some answers & information for you: Attachments

Monte 82 February 17, 2020 02:57AM

Re: Del, some answers & information for you:

D&P-OR 61 February 17, 2020 07:36AM



Sorry, only registered users may post in this forum.

Click here to login

Online Users

Guests: 14
Record Number of Guests: 302 on March 10, 2018