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Thread: Best metal detector for masking and silent masking

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  1. #16
    us
    manaloneblog.wordpress.com

    Jun 2010
    Wherever there be treasure!
    An older blue Excal with connector, remote, Skullie headphones, and various coils. Got rid of the rest of my machines.
    13,022
    7646 times
    All Types Of Treasure Hunting
    Quote Originally Posted by Tom_in_CA View Post
    Good write-up Bigscoop.



    I dunno about this. Wont' some machines allow for "averaging" at this point ? So for example if a tab read 28. And a dime read 79, then you might get a ~53 (albeit garbled, etc...). So that if you were electing to "pass tabs and foil" in this case, and had set your disc. to about 50, you'd get a coin UNDER (and completely obscured by) the tab. Right ?

    Machines models/brands differ in their ability in this dept.
    Here's my thoughts/experience with the subject of averaging. In order to generate an average then the processor has to have information regarding both targets, right? This means that the search field has to have access to both targets, keep this in mind as we explore this whole "pass through" theory.

    So here we are, on our favorite trashy beach or in our favorite trashy park sweeping our coil in search of masked targets. But what about those rare thin individual targets that we discover in perfectly clean ground. If our machine has the ability to pass through these items then why do we still get good, strong, and accurate ID on this targets? Why don't our sends pass right through them and generate very faint and/or weak returns? Yes, we do get broader and flatter returns from these thin items but this isn't the same thing as a truly weak return, the actual returns still being very strong and sometimes at surprising depths in very soft soils.

    I just don't believe "pass through" is a practical concept, even with the very best of machines capable of averaging unless both items, or portions of them, can be cleanly accessed. If "pass through" was as capable as advertised then the accuracy of many individual targets would be seriously flawed, especially those thin and oddly shaped items, etc. But this is just me based on my own experiences in hunting these trash infested areas.
    "Treasure is wherever it can be found."

  2. #17

    Mar 2007
    Salinas, CA
    Explorer II, Compass 77b, Tesoro shadow X2
    10,952
    6937 times
    Banner Finds (4)
    Quote Originally Posted by bigscoop View Post
    Here's my thoughts/experience with the subject of averaging. In order to generate an average then the processor has to have information regarding both targets, right? This means that the search field has to have access to both targets, keep this in mind as we explore this whole "pass through" theory.

    So here we are, on our favorite trashy beach or in our favorite trashy park sweeping our coil in search of masked targets. But what about those rare thin individual targets that we discover in perfectly clean ground. If our machine has the ability to pass through these items then why do we still get good, strong, and accurate ID on this targets? Why don't our sends pass right through them and generate very faint and/or weak returns? Yes, we do get broader and flatter returns from these thin items but this isn't the same thing as a truly weak return, the actual returns still being very strong and sometimes at surprising depths in very soft soils.

    I just don't believe "pass through" is a practical concept, even with the very best of machines capable of averaging unless both items, or portions of them, can be cleanly accessed. If "pass through" was as capable as advertised then the accuracy of many individual targets would be seriously flawed, especially those thin and oddly shaped items, etc. But this is just me based on my own experiences in hunting these trash infested areas.
    As usual, bravo on another good write up. I get what you are saying. And the "averaging" is really only tell-tale when objects are A) shallow, and B) preferably touching (or very close together anyhow).

    I've hunted underneath bleacher grandstand tearout before (which dated to the 1920s), which was an OCEAN of aluminum tabs and foil. All of which was in shallow hardpan (d/t it had been in perpetual dank dark conditions for ~70 yrs.). Thus depth wasn't the issue. And d/t the millions of tabs and foil (and the limited time we had to work before const. on the new grandstands started) we were forced to go high disc. Yup, kiss nickels and gold goodbye. We were angling for copper/silver.

    And I had set my Eagle SL II to reject ~47 and downwards. So that I'd *just* loose the beefy type square tabs. And I noticed that even though penny/dimes start at the high 70s, yet I'd get the benefit of "averaging", by choosing a lower # (as long as it wasn't low enough to start allowing in the trash I didn't want). I've sometimes get a coin under tabs.

    But , of course, who's to say there wasn't a "peak" of the coin? Who's to say if the coin was touching the tab(s) or not ? Another machine I've used for this purpose, which seems to "average", is various 2 filter tesoros (Sabre, Bandido, etc...). But yes, it probably only works when shallow, and coin close to the tab/foil above it.

  3. #18
    us
    Feb 2017
    Chattanooga Tennessee
    Garrett AT pro/fisher f70/carrot pen pointer
    332
    547 times
    Metal Detecting
    Quote Originally Posted by bigscoop View Post
    Here's my thoughts/experience with the subject of averaging. In order to generate an average then the processor has to have information regarding both targets, right? This means that the search field has to have access to both targets, keep this in mind as we explore this whole "pass through" theory.

    So here we are, on our favorite trashy beach or in our favorite trashy park sweeping our coil in search of masked targets. But what about those rare thin individual targets that we discover in perfectly clean ground. If our machine has the ability to pass through these items then why do we still get good, strong, and accurate ID on this targets? Why don't our sends pass right through them and generate very faint and/or weak returns? Yes, we do get broader and flatter returns from these thin items but this isn't the same thing as a truly weak return, the actual returns still being very strong and sometimes at surprising depths in very soft soils.

    I just don't believe "pass through" is a practical concept, even with the very best of machines capable of averaging unless both items, or portions of them, can be cleanly accessed. If "pass through" was as capable as advertised then the accuracy of many individual targets would be seriously flawed, especially those thin and oddly shaped items, etc. But this is just me based on my own experiences in hunting these trash infested areas.
    Man thanks for all the replies folks!

    It has a lot to do with soil I'm learning. As a new detectorist I have discovered soil has s HUGE influence on so much more than I realized. In Tennessee (Chattanooga) we have mid clay and Loam content soil plus a ton of chert. When I was in Ohio last week overseeing some groundwater well drilling I was feeling of the wonderful glaciated soils there. Wonderful loose soil compared to Tennessee.




    Sent from my iPhone using Tapatalk

  4. #19
    us
    manaloneblog.wordpress.com

    Jun 2010
    Wherever there be treasure!
    An older blue Excal with connector, remote, Skullie headphones, and various coils. Got rid of the rest of my machines.
    13,022
    7646 times
    All Types Of Treasure Hunting
    Quote Originally Posted by darktower007 View Post
    Man thanks for all the replies folks!

    It has a lot to do with soil I'm learning. As a new detectorist I have discovered soil has s HUGE influence on so much more than I realized. In Tennessee (Chattanooga) we have mid clay and Loam content soil plus a ton of chert. When I was in Ohio last week overseeing some groundwater well drilling I was feeling of the wonderful glaciated soils there. Wonderful loose soil compared to Tennessee.




    Sent from my iPhone using Tapatalk
    Soil can change everything, for sure, sometimes drastically. When I moved back to Indiana this was one of the first things I noticed.
    "Treasure is wherever it can be found."

  5. #20
    us
    manaloneblog.wordpress.com

    Jun 2010
    Wherever there be treasure!
    An older blue Excal with connector, remote, Skullie headphones, and various coils. Got rid of the rest of my machines.
    13,022
    7646 times
    All Types Of Treasure Hunting
    Quote Originally Posted by Tom_in_CA View Post
    As usual, bravo on another good write up. I get what you are saying. And the "averaging" is really only tell-tale when objects are A) shallow, and B) preferably touching (or very close together anyhow).

    I've hunted underneath bleacher grandstand tearout before (which dated to the 1920s), which was an OCEAN of aluminum tabs and foil. All of which was in shallow hardpan (d/t it had been in perpetual dank dark conditions for ~70 yrs.). Thus depth wasn't the issue. And d/t the millions of tabs and foil (and the limited time we had to work before const. on the new grandstands started) we were forced to go high disc. Yup, kiss nickels and gold goodbye. We were angling for copper/silver.

    And I had set my Eagle SL II to reject ~47 and downwards. So that I'd *just* loose the beefy type square tabs. And I noticed that even though penny/dimes start at the high 70s, yet I'd get the benefit of "averaging", by choosing a lower # (as long as it wasn't low enough to start allowing in the trash I didn't want). I've sometimes get a coin under tabs.

    But , of course, who's to say there wasn't a "peak" of the coin? Who's to say if the coin was touching the tab(s) or not ? Another machine I've used for this purpose, which seems to "average", is various 2 filter tesoros (Sabre, Bandido, etc...). But yes, it probably only works when shallow, and coin close to the tab/foil above it.
    I did a video exploring this very thing, mainly iron mask feature, but it's the same with about any alloy. I did this with the Excal and a borrowed CTX and E-Trac, the video I did with the Excal. Here is that video:



    Notice what happens each time the machine is allowed to reset, notice what happens after resetting as the iron and silver ring are passed through the search field at the same moment, just as they would be in the field.
    "Treasure is wherever it can be found."

  6. #21
    us
    Feb 2017
    Chattanooga Tennessee
    Garrett AT pro/fisher f70/carrot pen pointer
    332
    547 times
    Metal Detecting
    Quote Originally Posted by bigscoop View Post
    I did a video exploring this very thing, mainly iron mask feature, but it's the same with about any alloy. I did this with the Excal and a borrowed CTX and E-Trac, the video I did with the Excal. Here is that video:



    Notice what happens each time the machine is allowed to reset, notice what happens after resetting as the iron and silver ring are passed through the search field at the same moment, just as they would be in the field.
    Wow! I didn't know this. Wonder if it works with the Etrac?


    Sent from my iPhone using Tapatalk

  7. #22

    Mar 2007
    Salinas, CA
    Explorer II, Compass 77b, Tesoro shadow X2
    10,952
    6937 times
    Banner Finds (4)
    big-scoop, the machine "setting itself to" the field is not new. And is not unique to just those units. Any motion machine (since the inception of the Red Baron SPD and Whites 6000D in 1978-ish) can show the same thing. For example, if you drew an object up close to the coil in an air-test. And just hold it steady like you showed in your video. Then yes, the threshold returns (as it adjust to "that amount of metal") . Eg. a horseshoe , or wrench, or even conductive targets. Then a subsequent target is passed and sounds off just fine.

    But the devil is in the details: In actual field application of sweeping side to side, you never have a "constant" level of metal (whether conductive or iron) for there to be a "constant". So the machine will be perpetually readjusting to a myriad of concentrations of levels of targets. There's never a constant consistent level of iron in any one individual sweep of our detector coils So I don't see how your air test can be duplicated. You are holding the nail "still". Which can't be done with motion machines of needing to be swept (even if only subtly so).

  8. #23
    us
    manaloneblog.wordpress.com

    Jun 2010
    Wherever there be treasure!
    An older blue Excal with connector, remote, Skullie headphones, and various coils. Got rid of the rest of my machines.
    13,022
    7646 times
    All Types Of Treasure Hunting
    Quote Originally Posted by Tom_in_CA View Post
    big-scoop, the machine "setting itself to" the field is not new. And is not unique to just those units. Any motion machine (since the inception of the Red Baron SPD and Whites 6000D in 1978-ish) can show the same thing. For example, if you drew an object up close to the coil in an air-test. And just hold it steady like you showed in your video. Then yes, the threshold returns (as it adjust to "that amount of metal") . Eg. a horseshoe , or wrench, or even conductive targets. Then a subsequent target is passed and sounds off just fine.

    But the devil is in the details: In actual field application of sweeping side to side, you never have a "constant" level of metal (whether conductive or iron) for there to be a "constant". So the machine will be perpetually readjusting to a myriad of concentrations of levels of targets. There's never a constant consistent level of iron in any one individual sweep of our detector coils So I don't see how your air test can be duplicated. You are holding the nail "still". Which can't be done with motion machines of needing to be swept (even if only subtly so).
    Exactly! And yet you missed an important detail, when I referenced "a large" null, or an otherwise consistent state. That's exactly the point. This is also why I referenced the concrete boat ramp event, in which Mike was able to keep his machine in a constant state of null the entire time he was hunting it. If he lost that null, let the machine reset, then he simply allowed the machine to filter out the iron again before proceeding. Hence, "a large constant condition." I recently hunted a property that has huge iron plates underground, the same results here as well, though I only recovered a bunch of crap targets. But here's the catch as it applies to the subject of this thread, Me, Mike, all of those returns were above the iron where they could be seen, never below it. Yes, these are extreme cases, I realize that, but the simple notion that any iron mask feature can make iron transparent or invisible isn't very practical in our real world of metal detecting. They're still there and the processor is still having to deal with them. Yes? This is the same thing with notched out metals, all you're really doing is telling the machine, "You deal with them, but I don't want to hear about them." If "pass through" was really a practical application then why even offer features like notch? Why offer auto mask feature? Why not just allow the user the option of picking only those "fully masked" targets underneath? That's my point.
    Last edited by bigscoop; Jun 10, 2017 at 09:46 PM.
    "Treasure is wherever it can be found."

  9. #24

    Mar 2007
    Salinas, CA
    Explorer II, Compass 77b, Tesoro shadow X2
    10,952
    6937 times
    Banner Finds (4)
    Yes there are individual isolated hunt oddities where this could come into play. Like a concrete boat ramp with rebar laced all through it.

    One time I was hunting for a cache (for an estate looking for suspected buried jars the patriarch of the family was said to have buried). It was said to be "along a wall" of a "certain side of the house". Yet the house was plaster & lath type construction, with chicken screen inside the walls. So the moment I got within a foot of it, the toe of my machine would begin to pick it up.

    So I started mentally compensating for that, and letting my machine detune to it, so-to-speak. But it's never quite perfect, as you can never hold the machine an EXACT distance or level from the source of metal concentrations. Nonetheless, the theory came in handy, as I got a hint of an object that was coming in stronger than the chicken screen. And presto, got a jar of silver coins buried right at the base of the wall.
    RustyGold likes this.

  10. #25
    us
    manaloneblog.wordpress.com

    Jun 2010
    Wherever there be treasure!
    An older blue Excal with connector, remote, Skullie headphones, and various coils. Got rid of the rest of my machines.
    13,022
    7646 times
    All Types Of Treasure Hunting
    Tom, if I have the time on Sunday (suppose to go up north for some water hunting) I'll use the Excal and create a 100% "pass through" using a thin steel washer and a dime and I'll put this in video "if" I can capture clear audio of those returns? Not sure I can do this clearly enough? Can it be done, absolutely. Is it reliable...?
    RustyGold likes this.
    "Treasure is wherever it can be found."

  11. #26

    Mar 2007
    Salinas, CA
    Explorer II, Compass 77b, Tesoro shadow X2
    10,952
    6937 times
    Banner Finds (4)
    Quote Originally Posted by bigscoop View Post
    .... and create a 100% "pass through" using a thin steel washer and a dime ....
    Huh ? I lost ya bro. Not sure what you're referring to , in regards to the conversation of the thread here. What exactly are you going to do with a steel washer & dime ? In order to mimic a real world scenario ? Not understanding you

  12. #27
    us
    manaloneblog.wordpress.com

    Jun 2010
    Wherever there be treasure!
    An older blue Excal with connector, remote, Skullie headphones, and various coils. Got rid of the rest of my machines.
    13,022
    7646 times
    All Types Of Treasure Hunting
    Quote Originally Posted by Tom_in_CA View Post
    Huh ? I lost ya bro. Not sure what you're referring to , in regards to the conversation of the thread here. What exactly are you going to do with a steel washer & dime ? In order to mimic a real world scenario ? Not understanding you
    Well that's just it, "pass through" can even be done with the dime hidden behind a nickel, discriminate out the nickel and still be able to read the dime...."in a perfect world."
    "Treasure is wherever it can be found."

  13. #28
    us
    May 2011
    1,141
    2202 times
    Quote Originally Posted by bigscoop View Post
    Well that's just it, "pass through" can even be done with the dime hidden behind a nickel, discriminate out the nickel and still be able to read the dime...."in a perfect world."
    "In a perfect world"...and that's the catch.

    Here in my dirt as you get deeper everything up averages, even nickels that are at 5"+ will come in higher than quarters but once I noticed this affect I used it to find many great targets.
    On the other hand the more shallower targets still mostly act normal.
    This disc out a nickel thing but still find a dime might not work so great if they are close enough and you are looking for normal behavior because you still have that normal target averaging going on.
    In a pounded park I came across a signal that was into the bigger beaver tail range, a bit jumpy but still solid enough to go after it.
    I dug a shallow plug and pulled out a 45 merc at only about an inch or two deep which surprised me.
    I knew there had to be something else down there so I kept going and maybe about an inch deeper I come up with a 45 nickel.
    Just regular averaging which I guess can be considered another form of masking.
    If the coins were reversed, nickel high and the dime lower, I don't think it would have made much difference in the signal.

    Any detector could have found these coins and this park had been scoured by many since metal detectors were invented but still these coins were there until I came along and decided to dig this trashy tab signal.
    Using high disc and cherry picking I would have missed them completely.

    No matter what settings we have or the capabilities of our tools it is still important to use common sense and dig a little more uncommon signals...until we can get that X Ray vision thing working, anyway.
    bigscoop likes this.
    "I intend to live forever. So far, so good!".
    2017 Totals...Clad, silver pin, a silver bracelet, 11 silver coins including a freaking Barber quarter and a beautiful walking half, Plus 2 V nickels....still on the hunt for gold!

  14. #29
    us
    manaloneblog.wordpress.com

    Jun 2010
    Wherever there be treasure!
    An older blue Excal with connector, remote, Skullie headphones, and various coils. Got rid of the rest of my machines.
    13,022
    7646 times
    All Types Of Treasure Hunting
    Quote Originally Posted by digger27 View Post
    "In a perfect world"...and that's the catch.

    Here in my dirt as you get deeper everything up averages, even nickels that are at 5"+ will come in higher than quarters but once I noticed this affect I used it to find many great targets.
    On the other hand the more shallower targets still mostly act normal.
    This disc out a nickel thing but still find a dime might not work so great if they are close enough and you are looking for normal behavior because you still have that normal target averaging going on.
    In a pounded park I came across a signal that was into the bigger beaver tail range, a bit jumpy but still solid enough to go after it.
    I dug a shallow plug and pulled out a 45 merc at only about an inch or two deep which surprised me.
    I knew there had to be something else down there so I kept going and maybe about an inch deeper I come up with a 45 nickel.
    Just regular averaging which I guess can be considered another form of masking.
    If the coins were reversed, nickel high and the dime lower, I don't think it would have made much difference in the signal.

    Any detector could have found these coins and this park had been scoured by many since metal detectors were invented but still these coins were there until I came along and decided to dig this trashy tab signal.
    Using high disc and cherry picking I would have missed them completely.

    No matter what settings we have or the capabilities of our tools it is still important to use common sense and dig a little more uncommon signals...until we can get that X Ray vision thing working, anyway.
    As it is right now that masked item, or some portion of it, needs to be seen, or, multiple targets need to be making physical contact with each other so they can be evaluated as one. Otherwise, a completely masked item is going to remain a completely masked item.
    Tom_in_CA likes this.
    "Treasure is wherever it can be found."

  15. #30
    us
    Aug 2011
    417
    476 times
    Quote Originally Posted by darktower007 View Post
    Bring new this phenomenon is perplexing to me. I thought "man all these silver posts I bet I can find them too!" Yeah right it's tough!


    Sent from my iPhone using Tapatalk
    EXACTLY! There are "show boats" that flaunt silver and only tell half the story or lie. The hard work is rarely captured on media. That is why my videos show realistic metal detecting. Junk, clad, and sometimes a good find are the norm. Someone called videos that showboat "highlight reels" in another post. I tend to agree.

    Here is the thing. People like to see only what their perceptions tell them. They see a guy digging gold coins and they think they can dig gold coins. This is dangerous thinking especially if the person is someone who has little respect for the hobby. Not only can they endanger themselves and others, but they can get the hobby banned to.

    That is why i always try to preach responsibility to content producers. Tell the full story. Let them know the rarity of the situation if applicable. Im sure some will take offense by this stand, however, it is for the good of the community.

 

 
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