Interesting (or Just Plain Crazy?) Approach To Ferrous Limits Settings

[steveg]

12 minutes ago, Geordiedan said:

Great reply, thanks @steveg 

That affirms what I thought to be the case, and while I guess Toddy in that video may have his reasons for wanting literally everything to sound conductive, I think I'll run with something more like NASA Tom's suggested settings this weekend.

On the plus side, this was one of the key reasons I was interested in the Manticore.  With the 'Nox, setting Iron Bias to various degrees all I knew was that "some stuff" was being notched up as being more likely to be iron with each setting.  I ran f2 for a while but never really gelled with it (I've never dug a bottle cap in my life) so ended up back with regular Fe set at either 0 or 1 depending on the area.

With the Ferrous Limits and a suitable amount of trial and error (or, in time, cribbing the settings of the professionals once these have been out for a while in your native country 😄 ) then it should hopefully be possible to come up with some amazingly specific settings to isolate your preferred targets from the surrounding trash.

(Edit to add - I'll also be following the main Manticore thread over on Tom's board to see what he has to say on your tones query 🙂 ) 

Thanks again to all for your thoughts, it all helps me with my learning curve 👍

Dan

Dan, 

PERFECT!!  I am so glad that my post helped a bit, and yes, your understanding as I glean it from the quoted post, is precise/correct.  You "get it," in a very "complete" way.  SUPER!

Steve

[GB_Amateur]

1 hour ago, steveg said:

...IN THE BACKGROUND, the Manticore is essentially calculating a ferrous ID, and a conductive ID, for each target, analogous to what FBS machines do.  It's a bit more confusing, on the Manticore, because for some reason, Minelab does not allow us to SEE the FE-CO values directly (for a reason I will never understand).  BUT -- with that said, the FE and CO IDs ARE being "calculated" in the background, for each detected target.

So here's a thought:  can the Manticure screen be calibrated using an FBS/FBS2 detector and a set of test targets?  Then when you see a target's 2-d location you use the calibration to give you the FE number.  (You already get the CO number.)  Or is the scale invariably different on the FBS's compared to the Manticore?

Obviously this would only give you a ballpark FE value, which might not tell you much more than you already know.  Maybe a good learning tool for some, though....

[steveg]

GB_Amateur, interesting thought, but I don't think there's a way to do this, for a number of reasons that would be too hard to explain in a concise way.  Briefly, though, one issue is that yes, the "scale" is different, but moreso than just that, is that it's not a one-to-one relationship, in PART due to the fact that the underlying technology is different (FBS, vs. Multi-IQ), which means different targets will ID differently, just due to the nature/characteristics of the two different platforms.  Consider a nail/coin mixed target (i.e. the two objects in close proximity), for instance.  What the E-Trac may see as entirely a nail (with an ID of say 30-45), the Manticore on the other hand may see, very clearly, as two separate targets.  SO, there'd be no way to make a "one-to-one" transposition of the target's ID, or its "plot location on the screen," from the E-Trac screen, to the Manticore screen.  The underlying technology produces a different ID for the target...

Make sense?

BUT -- my suggestion is, instead of trying to figure out a way to "arrive at" the FE number through some "backdoor method," that we should simply press/request that Minelab offer (in a future software/version update) the OPTION on Manticore to display (if we choose to) BOTH ID numbers -- the FE, and the CO.  WHY leave the FE number in the background, where we can't see it, with NO OPTION to "turn it on," even if we want to?  I think EVERYTHING would be so much easier to understand, and to explain to others, if we could SEE BOTH the FE and CO VDIs, and thus see DIRECTLY how those two values relate to where a target is plotted on the 2D screen (and all the implications therein).  As you said, if nothing else, having the numbers would be a good "learning tool" that would help with the understanding of what is going on, for new Manticore users (especially those without FBS background).  For the life of me, I can't imagine why Minelab wouldn't have at least given us the OPTION to "toggle on" a FE-CO VDI readout, instead of forcing us into ONLY the CO VDI...

Steve

[steveg]

I should note, though, that there IS a way to more directly figure out a "FE" number, for what that's worth.

On the Manticore, the upper limits run from 0 to 14, and the lower limits run from 0 to 9.  SO -- think about it in terms of an x,y coordinate system.  This means that starting at the origin (0,0), and going UP the "y-axis," FE numbers go up to "14," while going DOWN the y-axis from the origin, FE numbers go down to "9."  So, mathematically, if we consider 0 to 14 values going UP the y-axis as POSITIVE y values, and the 0 to 9 values going DOWN the y-axis as NEGATIVE y values (i.e. 0 to -9), then technically, we could know, or at least estimate based on target plot position, what the FE number is.  If the target plots exactly halfway across the screen, in the "x" direction, the CO value is "50".  In other words, your "x" value, is 50.  Then, if the target also plots 1/2 way UP the screen (from the "zero line"), in the "y" direction, the FE value is "7".  So, the ID would be 50 CO (your "x" value) and 7 FE (your "y" value), so your ID (as an x,y pair) would be 50-7 (CO-FE), OR, in the more traditional FBS style, where the "y" value (FE) is listed first, it would be 07 50 FE-CO (y,x).

Meanwhile, targets plotting BELOW the "zero line" could be considered as having negative FE numbers.  SO, for example, a target plotting halfway ACROSS the screen, and all the way at the bottom, would thus have an FE-CO ID of -09 50. 

(...for whatever this is worth, LOL)

Steve

[Geordiedan]

34 minutes ago, steveg said:

 For the life of me, I can't imagine why Minelab wouldn't have at least given us the OPTION to "toggle on" a FE-CO VDI readout, instead of forcing us into ONLY the CO VDI...

The cynic in me wonders if that's being held back for a CTX-4040 with 2d map and "detailed FE-CO target technology" 😄 

Would be a great thing to see in an update though, maybe suggest to NASA Tom over on his board as he seems to have the ear of the development team as a whole.

[steveg]

Geordiedan,

I hear you, on the cynical thought process, LOL!

Yep, I have indeed mentioned this to NASA-Tom, and am hoping that MAYBE that could help this come to fruition.  But, I think more people requesting it/talking about it would carry some weight also...

Steve

[UT Dave]

I don't have mine yet (come on Minelab, send a pallet to Gerry!).  From reading the manual a few times, I was thinking the ability to adjust the equivalent of Equinox FE and F2, simultaneously and independently, was going to be a neat feature.  After SteveG's recent posts, I'm thinking so even more.

I have not been all that excited about the Target Trace screen.  Still, not really "excited" about it.  But, starting to realize that being able to visualize the effects of the FE limits adjustments to audio on targets in the ground, in real time, is, in fact, going to be quite useful.  I think.  Otherwise, I've mostly been looking at TT as a White's Signagraph with a (to me) slightly less useful signal strength indication.  I did like the Signagraph, and have expected to like TT, just have not really thought it was going to be much of a big deal.

- Dave

[steveg]

Dave,

Yes, your understanding is expanding!

If one uses target trace for NO OTHER REASON than to determine, at a given site on a given day, where to set their Ferrous Limits to accomplish that day's detecting goals, then target trace is an extremely invaluable resource JUST FOR THAT PURPOSE (entirely separate from the whole "what shape is the plot" that everyone seems to want to focus on).

To illustrate...

Consider this entirely made-up scenario...you are asked to find a lost men's gold ring, in the front yard of the owner's house (which you expect to read as a "mid-tone" target).  So, you start detecting.  However, you soon realize that it's not going to be as easy as you'd hoped, as you are digging TONS of "mid-toning" roofing nails.  You note that these particular targets are showing up at a specific location on the screen -- about halfway over (and thus why they are presenting a "mid tone"), and about halfway "up," i.e. halfway between the zero line, and the top of the screen (at the roughly "7" line, i.e. the horizontal line that passes through the "7" on the y-axis (FE = 7), or said mathematically, the line defined as y=7).

So, while these nails are plotting about halfway between the "0" line and the top of the screen, you note that your Ferrous Limits are set JUST BARELY ABOVE the location where the nails are plotting (i.e. they are plotting just below the "grayed out" portion of the screen -- which thus explains why they are "mid-toning").  So, you then go into your menu, find your Ferrous Limits adjustment screen, and adjust it so that you move the "grayed out" portion of your screen down, just a little, SO THAT the nails then fall WITHIN the grayed-out portion of the screen.  NOW -- those pesky roofing nails will NO LONGER REPORT A MID TONE, but instead will now give an iron grunt.  And NOW, you can hunt more EASILY, while looking for that ring, listening for mid tones (and not being distracted by what WERE mid-toning roofing nails).

While this is a simple example, such "strategic" use of Ferrous Limits, AND the fact that you can SEE what an adjustment of your ferrous limits does -- via the screen -- relative to the targets at your particular site, is of great benefit.  It allows YOU to adjust, on the fly, site-specifically, to determine which targets you are wanting/intending to present audibly as iron, and which ones you are wanting to present audibly as non-ferrous, based on what types of junk targets happen to prevail at that particular site.  YOU having that control over how the target is audibly identified, is a very interesting feature, from my view...

Steve