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null no ,null ,depth -16

bunn leonard

New member
depth has nothing to do with iron mask.......... sick of hearing about hunting in iron mask, youll gain know more depth than hunting in man sens at 24 or a stable setting with gain at 8 youll find it . if you want to dig everything go ahead have fun, in fact buy a dfx . youll are using iron mask in the wrong context.if its silver it will register vise versa , alot of people have learing problems with the ex because your hearing everthing you sweep over ie hot rocks highly minerilized ground all you - 16 hunters when you get a signal dont dig switch over and see if you hear the same thing .depth is sesitivity in man thats your depth if you like iron dig in-16. if im wrong contact minelab and ask for your yourself,dont you think they would say if you want more depth hunt in -16 ? . I have done both when hunting in -16 got tired of digging nothing wrong with farm equipent horseshoes nails . i program my ex thats the whole idea and concept behind the ex ,if you want to dig everything have fun. hope i havent pissed anyone off
 
I have only had my detector a couple days but I have read alot about the EX II so if I want to Hear and Dig more Iron like targets I would lower the iron mask -14, -15, -16. If i wanted to HEAR LESS Iron or iron like targets I would raise the mask -6, -5, -4.
Am I thinking correctly?
 
Nobody that hunts IM-16 or open screen digs every signal. And nobody says that you get always get more depth with open screen than with discrimination.

I know that Minelab says the way to go is to use patterns and they devote much space in their manual explaining how to do this. They sell metal detectors. But everyone I know who consistantly makes lots of finds does so by using as little discrimination as possible; not always open screen but as little discrimination as they can stand.

The main issue is that coins deep or comingled with trash can sometimes hit way to the left of the screen; an area that is typically disc'ed out. Leaving more of the screen open allows for more information, both audio and crosshair location to be noticed, as opposed to a simple null. Additionally, many of us feel the detector recovers more quickly from another tone than it does from a null.

On the depth issue, which has been debated a couple threads below, my take is that disc does not cause loss of depth in clean unmineralized ground away from any sources of electrical interference. In this situation you could have 10 pixels open in the upper right hand side of the screen and a silver coin would consistantly hit there. But there are only 14 acres of land in the whole US of A where you will find these conditions.

Most of the time mineralization, trash, alien space probes, menstrating gophers and the like will cause coins to hit in locations other than expected an most swings over the target. If you have these areas disced out you will not get a signal. Only the shallower targets typically give a strong enough signal to hit where they should on a consistant basis and that is why many people feel discrimination kills depth.

And on the null issue; seems to me that it is a case of the strongest signal usually wins and will pull the detector from a null. You could be detecting over a Sherman tank but if there is a silver coin above it the coin might pull the detector out of the null and give you a signal. Bury the coin under the tank, not a chance. Same goes for lots of nails and small objects. The more iron junk in the soil the less chance of you getting through to the coin. We all have detected areas that have had a couple inches of dirt removed and done much better. It wasn't because the explorer couldn't see that deep, but it couldn't see past all the trash.
 
You are correct and the strongest signal is the one with the dominant time constant. The relative position of co-located targets to the coil and the time constant for the targets is the fundamental way target are accepted or rejected. This is equivalent to how deep the null which is turning the audio circuits ON and OFF are turned ON or OFF. A very quick time constant turns them ON or OFF very quickly while a long one turns them off for longer periods of time. The purpose of FAST is to make this switching quicker. So we have a race condition, as they say in digital electronics, in which the dominant time constant control the switching time as it wins the race.

We have not discussed this in terms of ON time for a positive hits on two co-located targets. We normally get a longer wider hit on iron than precious metals due to the long time constant of iron. If it is too long then we miss a co-located coin so go by the warble sound which is the two different time constants or even more attempting to sound a tone. The other side of null is constant or a long sound that cause us to miss a co-located target close to iron. We can pick them out if we adjust the sweep and can hear the warble generated sound.

We end up with the impression that we can and cannot detect in null.
 
>>> alien space probes, menstrating gophers and the like will cause coins to hit in locations other than expected <<<

That's there's some funny stuff right there... :rofl:

I agree with everything you said...well stated. That's why I hunt in IM -16 most of the time. And of course that does not mean I dig all that stuff. I dig what sounds and looks good.
 
By using the Iron mask feature you can quickly jump to the discrim. pattern of choice.
I can say I personally hunt -15, in Ferrous Sound for fields and beach. Some may ask why......Reasoning.
I have found that small, broken jewelry, and hollow gold tend to move to the minus side.
Try this test for yourself, take a ring that may be broken. Spread the opening. Test it with detector. Push the ring together so the ends are touching. Test with detector.
In the test you will note that the target tone and value(reading) changed. Why......The eddy current changed from the solid to the opened ring(could not travel completely around ring).
I was unable to find my samples to add pictures or coins embedded in iron from the beach, and coins with iron fused to it. If I can find the samples I will add them to this thread.

OK, Why in the farm fields?
There are many different items in the fields Button ranging in all sizes, Coins in all varying amounts of wear, And the biggest reason the bounce.
In the areas that I hunt the soil is iron infested(pig iron, nails). This allows the detector to recovery quicker and I what to hear what is in the ground. The bounce refers to the triangle that is formed from a deep target, where by which the target will constantly move to the different positions while sweeping forming a triangle.

I hope that all this helps with some of the Why's and How come's.
 
More depth? Yes, depending on site conditions, soil type, and depth of coins.

Does IM -16 magically increase the transmit strength? Nope! The Explorer transmits at 100% power at all times regardless of any of your settings e.g. sensitivity, gain, IM, etc. Therefore the best possible signal you can receive on a target is in the control box waiting for you. Call this "gross depth".

You can then control depth via gain, sensitivity, iron mask, etc. You can eliminate certain signals (discrimination), filter weaker signals (sensitivity) and after that boost the fainter signals that are left in volume (gain). Via your settings you control "net realised depth".

If you decrease your sensitivity to 1 you will lose a lot of depth and miss targets. If you decrease your gain to 1 again you will lose depth on deeper targets and miss them. Isn't it reasonable then that discrimination could also adversely effect depth?

This depends on site conditions and target depth. In our local soils with the stock coil dimes and small cents start to sound pretty iffy at 7-8 inches. At 9 to 10 inches they can sound like crap. Now toss in some 200 year old rusty square nails at the same depth and discrimination becomes very important.

I have tested some deep targets that were quite iffy but nevertheless there in IM -16. I turned the IM up to -12 and they vanished, the iffy signal went 90% null 10% broken iron tone and the coin was gone. On occasion the reverse is true so its not 100%.

I'm willing to put up with all the iron noise in IM -16 because our deepest, most iffy signals are also generally the oldest most desirable coins. I may only dig one per hunt but its worth it. A half dozen 1900's indians, well that was exciting about 600 indians ago but a single 3 cent silver or an early indian that makes my day.

The second situation where IM can be an advantage is not so much depth related as it is improved target separation in iron. Again in our area with coins deep and lots of rusty square nails, most of the good targets that are left these days are hiding in the iron. Thats why they are still there after people have pounded these sites for the last 30 years.

In IM -16 I can often hear both the coin and the iron mixed together. Discriminate out the iron and poof the coin can vanish. Not always but often on these deepest, iffy targets. Our rusty square nails pollute a wide area. Its tough enough to get in close in IM -16, discriminating out the iron makes it all the more difficult.

The same target separation advantage applies to shallow modern trash polluting an area and overshadowing a deep nearby coin. With out the stretchy null getting in the way its often possible to hear both the shallow trash and the coin mixed together inbetween the two targets. I have to say those are my favorite ones to dig, there's nothing like digging the trash out of the way and then hearing the coin you thought was hiding there and going home with one many others had missed in the past.

I want to make the point that IM at -16 is beneficial mostly for those really deep iffy signals. Its not much of a help for an average 6 inch deep barber dime. If you don't have a lot of iron and your coins are not that deep, then there's nothing wrong with cranking up the IM and enjoying some peaceful silence versus all the low iron noise.

Now hunting an iron infested trash heap of a 1700's cellar hole is quite different. If there is a carpet of iron nails then running IM at -16 can be counter productive as the iron seems to overpower any other signals if you accept it. Discriminating out the iron via IM -15 or -14 scan be more successful in that type of condition.

Anyway those are my observations.
 
Yes, it's the same as running "wide open", everything accepted, including iron. I like to hunt that way and listen to what sounds good and looks good on the screen. I switch between Digital and Smartfind quite a bit too, and make note of the ferrous vs. the conductive content and I use the ferrous tones. After you hunt this way for a while it becomes easy to decide what to dig and what not to dig. Not for everybody though...it's a bit "busy". Not at all like my Fisher CZ-70, for example...which is silent until it hits a target and has no threshold.
 
I run my iron mask at -16 almost all of the time and I dig very little iron. And when I do, I know ahead of time that I'm taking a chance on a very iffy signal that is most likely iron. I'd say 1 in 4 of these iffy ones I take a chance on has a coin with it so I'll dig a quick plug and check with my X1 probe. Note I'm using ferrous tones.
 
You say:

"I have done both when hunting in -16 got tired of digging nothing wrong with farm equipment horseshoes nails . i program my ex thats the whole idea and concept behind the ex ,if you want to dig everything have fun."

One part of your question I think I can deal with in a response that might help. If you read Charles's(one of the best explanations)you'll see him mention that and I quote "I'm willing to put up with all the iron noise in IM -16 because our deepest, most iffy signals are also generally the oldest most desirable coins" .

You to would basically hear where that "farm equipment, horseshoes nails" is located and thats' if we are talking about stuff that is made of iron being ever present. The low tones that will come come out of your detector when it is set with a MANUAL set lower SENSITIVITY:

and Sounds Ferrous

when the coil passes over "raw"(not coated)ferrous objects, there will be a low tone indicating just that . This is what your detector is telling you. Here is a ferrous object and if there was a any non ferrous objects in between or under this iron that the Explorer HAS been able to detect at the time, then you will hear that tone. Detecting in such conditions with the -16 IRONMASK DO NOT rely TOO much on what you see on the screen. It's a chance situation that the Explorer and it's settings and it's coil setup MAY have detected a non ferrous object in or above or under or by the side of and in anyway amongst all that iron trash and you might want to investigate what it is. It's a choice you have to make. You, as we all are, are just the guys who have passed the coil over something with the settings and a chance approach(the correct angle)and that MIGHT have at the time, by virtue of the Explorers user input set up, "seen" the object . I say MIGHT because the Explorer is an amazing detector BUT don't expect TOO many miracles.(okay, maybe a couple)

It's really up to the detectors ability and the way it's used by you in this case and interpreting what it has told you and your willingness to dig that will find a desirable metal object in some of those tough detecting soil conditions.

There has to be some reality in the way a detector can find and most of it has been explained by many others.

Hope this has helped.

Hard Nosed Dave
 
Hi Shawn,

I'm a relative newbie on this machine (have it about 8 months). In the beginning, I used quite a bit of discrimination; trying to come up with my own patterns for coins / jewelry using "learn" accept / reject. The funny thing is, now I use very little discrimination as I prefer to hear everything or as much as I can stand. The only time I'll use more disc. is when I'm in a really trashy area. Settings just depend on the conditions where I'm hunting.

At the beach, I can hunt the wet packed sand / shallow surf in IM-16 (in Ferrous) and run the sensivtivity at max. To answer your question, in IM-16, yes, you'll hear all the iron. If I'm in an area (dirt or sand) where there's a bit of iron, I'll run the IM mask at -14 or -12. Anything that sounds "iffy" can be checked by going to a clear screen (all metal)... you can then try to hear if iron is the iffy signal or there's a possible target near some iron..
 
Ferrous tones should just about eliminate iron digging. I have never understood why conductive/size is the factor preset when ferrous seem to the the natural way to indicate the difference for metals.

I don't think I would do very good now with conductive/size compared to ferrous. I also find audio1 to be of interest so am using that at this time. I can see better discrimination, or at least think I can, with a longer analysis of the deeper targets. I feel sure some of the really deep ones were located because of using Ferrous and Audio1. I don't however have the best hearing so that has to be considered.
 
Hey Charles,

Agree with your post 100% except on meaning of greater depth. Basically IM-16 or open screen allows you to hear crappier signals whether shallow or deep. Since deep signals tend to more often be crappy it appears that we are detecting deeper. If you were running much discrimination at all you would get a null over these targets; the detector DID see the target, but a null is a null is a null. Running open screen might give you just the squeak of info needed to get your attention and check it out.

This issue is one of those that many take as gospel: more disc means less depth. It isn't per se, but in most ground conditions yes. As your post says the discrimination does not affect the TX signal.

Another similar minelab urban myth is sweep speed, slower is deeper. I've done lots of tests and faster actually goes deeper. If you slow down to a creep- especially in Auto Sens- explorer won't see it at all while when you rocket past it gets it. Again, problem is in almost all detecting sites the amount of trash makes this impossible. The electronics, even with FAST on, can't analyze the signals quickly enough to sweep quickly.

Chris
 
The detector design engineers I have talked to over the years, some such as Gifford havd questions and answers on the Internet as does George Payne, tell us that any discrimination gets less depth.

So, we got this problem in defining more depth. I agree that depth is the same unless we do something with the coil to warp the TX signal or lift the coil higher from the ground. We got what we got.

But, no matter what we do, scoping away some dirt, praying, better settings, better hearing, headphones, chanting, if we find deeper coins then it seems valid to say we get more depth. The manufactures have sold us on "more depth" with PR so it is a confusing issue.

I have argued long and hard on those long cold winter days that we don't get more depth but are just more effective with our detectors.

I am told that the "discrimination process" circuits and such will not report signals as deep as all metal. The discrimination process "eats" some very faint signals. This seems correct as I have often thought of how deep the old VLF would hit a nail head. It was after the introduction of discriminating that depth and not detecting some coins, rings, pulltabs, started to be a major concern.
 
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