A machine that cancelles strong signals.

[DannyB1954]

Is anyone aware of a metal detector that can hide strong signals and let the weak ones through?
I think this would be a handy feature for park hunters who are looking for the deeper older coins and jewelry, ignoring the upper level trash.
It is hard to ignore a strong signal and it is a bit distracting when listening for the soft ones.

 

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[Lanny in AB]

I see that you have a lot of detectors, and so I realize you're not asking about discrimination which will completely block out unwanted signals allowing other desirable signals to be heard, but that will not stop the power of the larger signal from overshadowing or perhaps masking a very weak, positive signal.

So, I'm intrigued by your question and hope that someone has an answer, if such technology exists. I can see a real value to it. So, I'd like to hear what they have to say too.

All the best,

Lanny

 

[Treasure_Hunter]

I am not aware of any that will do that per sue.....The CTX 3030 will show multiple targets at same time and give you TID for each target, as well as tell you if one is junk, that is as close as I know to what you want...

 

[gamiller]

Interesting idea. Probably would need pose this type of question someone who really knows their stuff, wonder if it's possible?

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[DannyB1954]

I am thinking of a variable resistor or digital control that can be adjusted for clipping signal strengths over what it is set for. I don't really know what the signal strengths are, but say a pop top at 1 inch reflects 50 dan units, (named after me), and a coin at 6" reflects 5. the selector can be set so that anything over 40 dan units will be ignored. This would be adjusted as per the site's trash content. It would seem an easy task for a microprocessor. Most can figure out how deep something is, Just instruct to ignore anything less than what you set the dial for. Anything strong enough to be new is to be ignored. The dial could be calibrated by depth or by signal strength.

The purpose of this would be to pass over clad coins and aluminum trash. If minimum wage is $7 an hour, you would have to dig up 28 quarters a hour to meet that. I can see where this would benefit relic hunters as well. I don't want the pull tab lost a year ago, I want the coin or ring lost many years ago. What you would lose in lost targets you would more than make up for in productive digs.

 

[gamiller]

Well I thought if the excal can null over iron maybe a certain strenght signal could be blocked also

 

[DannyB1954]

I realized that this topic should have been under general metal detecting, so I started it there as well. My apologies to admin.

 

[Jim Hemmingway]

DannyB1954... what you're after is a feature called surface blanking or surface elimination. Some past detectors models had this feature insofar as it was adjustable from one to four inches depth and calibrated to penny size targets signals. I don't try to stay current with detectors designed for coin hunting, but you should check out Garrett Metal Detectors... the GTI 2500... it does have this feature available. Here's the link, hopefully it won't be removed by moderators.

Garrett GTI 2500 Key Features

You will find there is no quick and easy technique to coin detect without sacrificing good targets. Usually larger targets at depth... such as silver half-dollars... will have similar target signal strength to pennies at shallow depth. Of course you may never know it was there if surface blanking or elimination was enabled at the time. Additionally... target separation or 'see through' capability obviously will be affected when using this feature.

Most older parks in the Toronto area held old Edwardian and Victorian silver coins at only a few inches depth. So it is difficult to predict or anticipate just what to expect in that regard... but in all probability at least some will exist at shallow depths just about anyplace you choose to search.

Nearly all the coins and tokens pictured below were within five inches of the surface and that goes for the majority of the old silver coins, large pennies, and tokens we found over many years. Many of these would not have produced a signal had we used a surface blanking feature.

Hope this helps, good luck and all the very best with your coin hunting endeavors.

Jim.

​

 

[DannyB1954]

It was pointed out to me that If a target came under the tip of the coil it may be weak and trigger a sound. Once over the center it would be stronger and get cancelled out. This would lead one to back the coil up and think it was a deep coin under the coil. If you dug there, nothing would be there.

 

[DannyB1954]

There is no detector that advertises it can do this. However, there is a two machine technique. Detect with a Minelab GPX5000 and mark spots you get a signal. Then go over the same spots with a VLF using discrimination. Dig the stuff the VLF does not see.

One might be able to use high gain on a vlf, then low gain. If the signal is lost on the second pass it might be deeper.

 

[DDancer]

Jim pretty well hit it on the head. The GTI 2500 is the only detector that I can think of and having used it in the past the surface elimination feature works reasonably well but you'll still get some break over with large shallow targets. Said targets will also mask targets around them as well. I used it in bottle cap havens with some sucess but found I was better off using the Target Imaging to do what your looking for~ ie look for older deeper targets. Still had to dig those caps.

 

[Stealth 914]

Sort of reminds me of the gold fields heaps of Minelab gpx 5000 have been over same ground and gets all deep stuff then along comes these new smaller coils and pick up the closer to surface nuggets so if you are after deep maybe go bigger coils to start with. This also happens with me with my CTX 3030 and 17" coil I miss a lot of close to the surface stuff until I back the sensitivity way off like back to 8 from 26-28 which is great for covering lots of ground to get newer spendables. Lots of trial n error to miss all of the top few inches of soils but good luck with what you try.
Cheers

 

[DannyB1954]

Thank you all. In my park, the last generation have been a bunch of pigs tossing garbage on the ground. I was hoping for a solution to bypass this, but apparently greater minds than mine have also been there before me and the cure seems to be worst than the problem.

 

[DDancer]

I'm pretty sure every detectorist on this site would love a magic wand that'd just see the good stuff and leave the junk behind but I have my doubts it'll ever happen.... build a better mouse trap and all Hehh. Part of what makes this hobby so challenging are the limitations that the junk imposes like it or not. Luck with that park.

 

[Joe(TX)]

...The better mouse trap has already been built......but for this day and time....it seems that technology has been forgotten!! The Compass Coin Magnum has such a feature....one can set it up to discriminate against pull tabs and still find the nickels and jewelry if the depth is greater than 2.5 inches! This detector has a depth blanker which can eliminate most junk down to the depth of 2.5 inches. Other brands also have a similar feature such as the Tesoro Royal Sabre and I believe that some of the Bounty Hunter Big Bud Pro's have this feature! Depends on what I am searching for but I tend to like to dig up all of the large signals first in a small grided off area....some of the small deep signals can be masked by a more shallow large object! I do not like to dig pull tabs anymore than anyone else but if the area only has a few I would probably just dig em anyway! Now if the pull tab count came to over 100 to 200....I would definitely blank them out! The only problem that I can see with Blanking is that you may ignore that shallow large 14K Gold Ring!