ID in iron, I didn't know this..

[jayhop]

I did a quick test when I got home today.
I wanted to get a better idea of the settings I should use at a really good site that is full of square nails. Saturday and Sunday I had to use an FE of 5 to avoid digging so many nails. And I still dug some at 5.
I have a test I do with a coin and 3 square nails. These are nails I've dug thinking I had a nonferrous target.
The nails are positioned at 3, 12 and 9 o'clock pointing at the coin. I sweep the coil in the 9 to 3 o'clock directions.
Today I was getting a good tone mixed with an iron tone. But my ID was consistently a negative number. When I'd wiggle I got a good ID, in the 50s on the copper penny.
I can't remember why, but I cut the horse shoe off. I then swept the coil over the targets. I couldn't believe what happened. With the horse shoe off I got a positive ID in the 50s. I'm talking about a normal sweep, not a wiggle.
Some of you may already know about this but it's new to me.
I had to lower the FE to 4 to get decent separation , and use a recovery of 7. This was in Park 1. First tone bin set all the way up to 19.
One thing about doing separation test. You should use a full sweep, only wiggle once you have heard a good nonferrous tone. That's my opinion anyway.
So bottom line is, once you know you are in the iron, cut the horse shoe off. Again my opinion.
Please give me some feedback if you try this test.
I have pictures attached. They are hard to see but there are 3 nails around the penny .

 

[laplander]

slow n low on you tube with Neil Jones. Watch the one where he shows the Minelab engineer Mark a thing or two about detecting and the "Minelab Wiggle" Neil is not a whiz on you tubing but he knows about detecting in real world conditions.
HH Jeff

 

[sgoss66]

Sometimes talking about horseshoe "on" or "off" is a bit confusing.

To clarify just for the sake of understanding...

From the default state of the machine (targets with negative ID discriminated), I ALWAYS press the horseshoe button once, at the start of the hunt, to "accept all targets." So, as we all know, "accepting all targets" or "iron targets discriminated" are the two options that pressing the horseshoe button allows; it "toggles" between these two states (iron accepted, or iron rejected).

So, it sounds like you do the same thing -- i.e. press the horseshoe button at the start of your hunts, to "accept all targets." I assume this because you said you were getting a mix of iron tones and high tones on your penny, and so obviously you were not discriminating iron at that point, but instead "hearing" the iron. So, on this "part high tone, part iron tone" situation (nail next to coin), you were getting a consistently negative (iron) VDI, but you said you could "improve" the detection of the coin -- i.e. mostly high tones and an ID in the 50s, when you did the "Minelab wiggle," correct?

THEN, you pressed the horseshoe button, which means you were now discriminating out the iron. And you said that at that point, even with a "regular" sweep, you were getting VDI consistently in the 50s.

So, I am a bit confused. You say this "surprised" you. BUT -- unless I am missing something, this is exactly what MUST happen, right? In other words, if you pressed the horseshoe button to begin discriminating out the iron, then the machine could ONLY report whatever high tone/positive "coin-like" VDI it could generate; the "dominant" iron tones and ID that the machine WOULD OTHERWISE HAVE REPORTED, were physically eliminated when you chose to discriminate the iron. So, the only thing left for the machine to report on, were the "good" tones/ID. Am I missing something?

The other thing, though, is this. Let's pretend you had a nail ONLY, that was ALSO reporting a mix of high tones (falses off the head of the nail) and iron tones. Then, you press the horseshoe button such that iron is discriminated. Then, you sweep the target. THE EXACT SAME THING SHOULD HAPPEN. You of course will no longer hear the iron, BUT, you WILL hear the falses, and ONLY the falses, and you'll ONLY see the "good" VDI numbers that accompany the falses. Again, it's for the same reason. You would have FORCED the machine NOT to report the iron tones/VDI, so the ONLY choice it has is to report the FALSES to you, which can then allow that nail at times to perhaps more easily fool you into thinking it's a coin -- as ALL you would hear would be the "good" reports generated by the nail (the falses), without hearing ANY of the "bad reports" (the nail itself -- though you would hear a threshold null if you set it up to run audible threshold).

Thoughts?

Steve

 

[jayhop]

Sometimes talking about horseshoe "on" or "off" is a bit confusing.

To clarify just for the sake of understanding...

From the default state of the machine (targets with negative ID discriminated), I ALWAYS press the horseshoe button once, at the start of the hunt, to "accept all targets." So, as we all know, "accepting all targets" or "iron targets discriminated" are the two options that pressing the horseshoe button allows; it "toggles" between these two states (iron accepted, or iron rejected).

So, it sounds like you do the same thing -- i.e. press the horseshoe button at the start of your hunts, to "accept all targets." I assume this because you said you were getting a mix of iron tones and high tones on your penny, and so obviously you were not discriminating iron at that point, but instead "hearing" the iron. So, on this "part high tone, part iron tone" situation (nail next to coin), you were getting a consistently negative (iron) VDI, but you said you could "improve" the detection of the coin -- i.e. mostly high tones and an ID in the 50s, when you did the "Minelab wiggle," correct?

THEN, you pressed the horseshoe button, which means you were now discriminating out the iron. And you said that at that point, even with a "regular" sweep, you were getting VDI consistently in the 50s.

So, I am a bit confused. You say this "surprised" you. BUT -- unless I am missing something, this is exactly what MUST happen, right? In other words, if you pressed the horseshoe button to begin discriminating out the iron, then the machine could ONLY report whatever high tone/positive "coin-like" VDI it could generate; the "dominant" iron tones and ID that the machine WOULD OTHERWISE HAVE REPORTED, were physically eliminated when you chose to discriminate the iron. So, the only thing left for the machine to report on, were the "good" tones/ID. Am I missing something?

The other thing, though, is this. Let's pretend you had a nail ONLY, that was ALSO reporting a mix of high tones (falses off the head of the nail) and iron tones. Then, you press the horseshoe button such that iron is discriminated. Then, you sweep the target. THE EXACT SAME THING SHOULD HAPPEN. You of course will no longer hear the iron, BUT, you WILL hear the falses, and ONLY the falses, and you'll ONLY see the "good" VDI numbers that accompany the falses. Again, it's for the same reason. You would have FORCED the machine NOT to report the iron tones/VDI, so the ONLY choice it has is to report the FALSES to you, which can then allow that nail at times to perhaps more easily fool you into thinking it's a coin -- as ALL you would hear would be the "good" reports generated by the nail (the falses), without hearing ANY of the "bad reports" (the nail itself -- though you would hear a threshold null if you set it up to run audible threshold).

Thoughts?

Steve

I have just always done separation test with the iron on. Horse shoe engaged.
And most of the time that's the way I hunt, iron on.
What I found out today is that with the iron off I got a totally different ID than with it on.
Like I said, I didn't know. And I'm sure I'm not the only one.
Also, as many testing videos as I've seen I've never heard anyone talk about this.

 

[sgoss66]

jayhop,

Got it! Makes sense. And yes, I can see how that's a nuance that many may not have realized...

The way you set up your machine, is the same as I do -- iron "accepted." But, if you discriminate iron, then on a "mixed ID" target, the machine only has the option of reporting the "accepted" VDIs; any VDI discriminated out, will not/can not report.

Another interesting aspect of your post, is how you were adjusting iron bias, to deal with the nail falsing. Here's what I wonder. Let's consider your coin and nail situation. You said the machine was reporting some iron IDs, and some 50s IDs, while using a "mid-range" iron bias. So -- we know that the machine was clearly able to separate and see both targets.

Now, let's say you had lowered your iron bias to zero. Doing so, you would have certainly heard a mix of BOTH the iron low tones, and the coin high tones, very clearly, and probably a greater percentage of high tones than when you had the bias set higher (the idea being, of course, that the higher you run the iron bias, the more you are "biasing" the machine to report the target to you as "iron"). NOW -- let's say you then ran your bias all the way up to 9 (I think that's the max). And let's say after doing so, set at maximum iron bias, the machine then reported NO high tone, ONLY an iron tone.

Now, here is my question. What if THEN, with bias set at 9 and the machine reporting ONLY IRON, you then toggled your horseshoe button to discriminate iron? Recall, the machine is SEEING both targets, but it is being "biased" (by the maxed-out iron bias setting) to REPORT the targets ONLY as iron. SO -- knowing that the machine DOES "see" the coin (as was proven with lower "bias" settings), does the machine then, with iron discriminated out, report the high tone and 50s VDI, the same as you experienced, DESPITE your iron bias setting causing the machine to report the target as entirely iron? OR -- does the machine now report nothing (only a blank in the threshold), due to the fact that you have BOTH discriminated iron, AND "forced" the machine to report the nail/coin target AS iron, via the iron bias setting?

Said differently, does discrimination act on the "raw" (for lack of a better word) signal -- i.e. the signal as it exists PRIOR to iron bias being applied (i.e. both targets being reported), OR, does discrimination act on the signal AFTER iron bias is applied (in which case, in my example, the coin/nail would be ENTIRELY discriminated).

IF the latter is the case, and I am guessing that it is, then running iron bias high enough to eliminate any high tones, AND THEN, toggling the horseshoe button to discriminate iron, would mean that UNLIKE what you experienced (hearing ONLY high tones and 50s VDI once you toggled the horseshoe to discriminate iron), you INSTEAD would have had the OPPOSITE occur -- NO high-tone audio and NO 50s ID, and also of course NO iron tone...just a blank in the threshold.

This has raised some questions in my mind regarding the relationship between iron bias, and discrimination. I have never thought or worried about this, since I run ZERO bias, and ZERO discrimination. BUT, for those that do, it would seem that these might be important things to think through...

Steve

 

[jayhop]

jayhop,

Got it! Makes sense. And yes, I can see how that's a nuance that many may not have realized...

The way you set up your machine, is the same as I do -- iron "accepted." But, if you discriminate iron, then on a "mixed ID" target, the machine only has the option of reporting the "accepted" VDIs; any VDI discriminated out, will not/can not report.

Another interesting aspect of your post, is how you were adjusting iron bias, to deal with the nail falsing. Here's what I wonder. Let's consider your coin and nail situation. You said the machine was reporting some iron IDs, and some 50s IDs, while using a "mid-range" iron bias. So -- we know that the machine was clearly able to separate and see both targets.

Now, let's say you had lowered your iron bias to zero. Doing so, you would have certainly heard a mix of BOTH the iron low tones, and the coin high tones, very clearly, and probably a greater percentage of high tones than when you had the bias set higher (the idea being, of course, that the higher you run the iron bias, the more you are "biasing" the machine to report the target to you as "iron"). NOW -- let's say you then ran your bias all the way up to 9 (I think that's the max). And let's say after doing so, set at maximum iron bias, the machine then reported NO high tone, ONLY an iron tone.

Now, here is my question. What if THEN, with bias set at 9 and the machine reporting ONLY IRON, you then toggled your horseshoe button to discriminate iron? Recall, the machine is SEEING both targets, but it is being "biased" (by the maxed-out iron bias setting) to REPORT the targets ONLY as iron. SO -- knowing that the machine DOES "see" the coin (as was proven with lower "bias" settings), does the machine then, with iron discriminated out, report the high tone and 50s VDI, the same as you experienced, DESPITE your iron bias setting causing the machine to report the target as entirely iron? OR -- does the machine now report nothing (only a blank in the threshold), due to the fact that you have BOTH discriminated iron, AND "forced" the machine to report the nail/coin target AS iron, via the iron bias setting?

Said differently, does discrimination act on the "raw" (for lack of a better word) signal -- i.e. the signal as it exists PRIOR to iron bias being applied (i.e. both targets being reported), OR, does discrimination act on the signal AFTER iron bias is applied (in which case, in my example, the coin/nail would be ENTIRELY discriminated).

IF the latter is the case, and I am guessing that it is, then running iron bias high enough to eliminate any high tones, AND THEN, toggling the horseshoe button to discriminate iron, would mean that UNLIKE what you experienced (hearing ONLY high tones and 50s VDI once you toggled the horseshoe to discriminate iron), you INSTEAD would have had the OPPOSITE occur -- NO high-tone audio and NO 50s ID, and also of course NO iron tone...just a blank in the threshold.

This has raised some questions in my mind regarding the relationship between iron bias, and discrimination. I have never thought or worried about this, since I run ZERO bias, and ZERO discrimination. BUT, for those that do, it would seem that these might be important things to think through...

Steve

It will take me a while to decipher all that information, but I will.
But to clear up one point...
I was only getting negative VDIs with mixed tones on a full sweep of the coil, when iron was on. (NO positive VDI)
I didn't get a positive VDI (with iron on)until I wiggled or hovered.

 

[Mark kus]

Good points I hunt the same way it pays off to test if in doubt I dig it.
Mark

 

[laplander]

It will take me a while to decipher all that information, but I will.
But to clear up one point...
I was only getting negative VDIs with mixed tones on a full sweep of the coil, when iron was on. (NO positive VDI)
I didn't get a positive VDI (with iron on)until I wiggled or hovered.

which is exactly what Neil consistently showed to the Minelab Engineer Mark. The Manticore would show and hear iron, but he heard something and wiggled over it and the non-ferrous would build on the 2d screen with some audio. The 2d screen is going to be a valuable tool for those that understand this concept and utilize it.
HH Jeff

 

[jayhop]

which is exactly what Neil consistently showed to the Minelab Engineer Mark. The Manticore would show and hear iron, but he heard something and wiggled over it and the non-ferrous would build on the 2d screen with some audio. The 2d screen is going to be a valuable tool for those that understand this concept and utilize it.
HH Jeff

I've seen that video before but to be honest, I really didn't catch on to what he was doing. But now I get it.
My approach from now on will be to disengage the horseshoe when I get in a heavily iron infested area.

 

[sgoss66]

It will take me a while to decipher all that information, but I will.
But to clear up one point...
I was only getting negative VDIs with mixed tones on a full sweep of the coil, when iron was on. (NO positive VDI)
I didn't get a positive VDI (with iron on)until I wiggled or hovered.

Understood, on the negative VDIs until you "wiggled" the coin...

My apologies if what I wrote was confusing. I had a hard time trying to write my thoughts in a clear/simple way. But, I think the reason I wanted to say all of that is that I suspect that some of these "nuances," including the understanding of the interactions between iron bias (or, on the Manticore, the conceptually related "ferrous limits" settings), and discrimination, as well as use of iron audio and threshold, may be important as far as mastering these new units...

Steve

 

[jayhop]

No not confusing, just will have to read it when I have more time to think about it. Working today.