On my mind -- Random Thoughts

On my mind -- Random Thoughts

It woold be nice if some people would stop publishing links to their YouTube channels.

midalake Wrote:
-------------------------------------------------------
> On my mind -- Random Thoughts
>
> It woold be nice if some people would stop publish
> ing links to their YouTube channels.

. . Why . . . does that bother you? . . . . I'm all for it if I can learn some tidbits of detecting knowledge.

Lees point about newer detectors .... is in my opinion one of the huge improvements. Every since the Etrac more machines have required less of a learning curve and are very effective out of the box. We really had a learning cure with some of the older machines..... IE DFX and Explorer. One of the hardest things for many to learn to do is slow down and listen for the weaker targets. We tend to move fast and hear LOUDER targets which can lead to the complaints of ..... we dont get a lot of depth while others do.

The machines sees and hears a lot...... disc is just turning off what you hear at the headphones. Its been great that more machine have faster processors and recovery..... makes working in trash much easier especially with the larger standard coils now days.

Little video I did.
Talks about possibility of purposely allowing detector to be purposely set to lower standard and give audio.


[m.youtube.com]

David..........That’s exactly what Ferrous Limits: Upper does!

Throughout the Decades....... regardless of brand/unit........due to physics.,.,.,.,.,., over 90% of iron nails....,,,,,,,...... will high-tone false: right at (or just slightly below) the Zinc Penny range. (Right dead in the middle of Indian Head Penny conductivity).

Hmm...

I'm trying to make sense of this, based on my experiences.

Hmm..

Is this true of SMF units? This is not a statement I would have made just based on my own personal observations. But, I note that my bias is about 98% of my hunt time over the past dozen years has been running SMF (Minelab) units...

The problems I have with nails -- mainly deep square nails -- are NOT that they attempt to masquerade as a deep IHP, but as a deep silver coin. In fact, I'm trying to think of a case where I have hit a deep target, and determined "likely IHP" in my mind, pre-dig, and then find nothing but a square nail in the hole...

Hmm...

Can you elaborate?

Steve

Steve......... absolutely! (Because I was very short on time...when I made the post last night).

* Rusty and/or bent nails .......... (even higher propensity for square nails)......... that present a fairly strong detection signal.........in low/no mineralization dirt.,.,.,.,.,.,.,.,.,.,.,.,., will present a Indian Head Penny high-tone false. (((Mid-to-high 50's ID on Manticore))).
* FRINGE DEPTH rusty and/or bent nails .......... will 'ID bounce' from Indian Head Penny conductivity........ all the way up to Silver Half Dollar......... in low/no mineralization dirt.
* Rusty and/or bent nails .......... that present a fairly strong detection signal (nails that are not that deep).... in BAD MINERALIZATION.......... can/will emulate a silver coin (Silver Dime, Silver Quarter, Silver Half Dollar) false ID.
* FRINGE DEPTH rusty and/or bent nails in bad mineralization........ have a very strong propensity to false-ID as Silver Half Dollar or Silver Dollar.

NASA-Tom,

AHH. This is VERY interesting. So, what I conclude is that based on my experience that rusty/bent or square nails, generally deep ones, will "false" as a silver coin, are falsing as "high tone" vs. "Indian-Head-Penny-range" tone, because I'm detecting in at least moderately mineralized dirt...

THAT makes sense...

Thanks!

Steve

True/Correct!

For a design engineer to be innovative ........ it is vital to know what you are MISSING......,,,,,,,in the ground.

There are WAY TOO MANY variables to set rules. Sometimes you have to dig large unknown targets which are masking good targets. If there are square nails it also could hold very old coins/relics. Old trash protects old coins. Are you willing?

And that's just it!
I'm now of a different mindset. For the past few years........ I have been running iron discrimination (via a form of tone-break).....on what ever unit I'm using (((usually Manticore............sometimes D2)))........ in carpets of nails. Extremely low tone-break/Ferrous Limits/Iron Disc....in carpets of nails.....sure does induce a lot more 'falsing'.......yet........also allows a non-ferrous target (amongst nails) .... to burp through the headphones ...a bit more readily.
BUT......... here is what I have REALLY changed =
I now (more than ever) dig: micro-pits. ---- I find a (potentially heavily masked) non-ferrous target....with a metal detector....in carpets of nails. I dig a 10" x 10" x 10" plug. Yesteryear....... I would try to find the non-ferrous target as quick as possible.....and move on. Now........today........ I remove EVERY piece of metal out of the dug plug. Then........ I ALSO put the pinpointer down in the hole....and 'micro-pit' dig. This small 10" pit (hole) will get every piece of metal ...recovered out of the hole....... using a Fisher F-Pulse pinpointer (deepest pinpointer on the market......as of current time). I am always surprised as to 'how many' metallic implements come out of the ground. MOST are ferrous. Some are non-ferrous . , . , . , . , . , . , . and some of these non-ferrous targets are a genuine 'surprise'. Right now......... I ONLY dig micro-pits (and mini-pits) in areas that are heavily littered with SQUARE nails. (Older-generation nails).
Recently........ I have been digging mini-pits. This is performed without a detector. Only a shovel and a pinpointer. I'll dig a 2-foot x 2-foot x 2-foot plug out of the ground....... in a prime location....... and have-at-it with a N52 (very strong) Rare Earth magnet in one hand........ and the Fisher F-Pulse pinpointer in the other hand. ((( I love it.... when the magnet is NOT picking up the pinpointer-detected target!!! ))) My most recent site..... is producing 27 nails...... to 1 non-ferrous target. 27:1 ratio. When you come home with 25 - 30 non-ferrous targets...... one or two of them....... are bound to be good 'keepers'.

In Ft. Meade, Florida....... at a even older site(s)....... I would dig regular 'pits'. These usually ended up being 13-feet x 9-feet (by......down to: 31" deep). I was averaging 105:1 .....ferrous-to-non-ferrous ratio volume of targets. Sometimes the non-ferrous target....would be VERY significant.
In Archaeological site recovery......... I would dig multiple 1-Meter X 1-Meter pits.

In a nutshell: You would be SHOCKED as to 'how' terrible today's metal detectors are....at unmasking. It's: THE PAINFUL TRUTH.
A pit-dig will: Expose! A pit-dig is: an eye-opener.

Yes....... it takes a certain monomaniac/psychosis mindset to perform micro-pit, mini-pit & pit digs.
IF you want to dabble into this....... I would recommend starting out ONLY with micro-pit digs........ a small N52 Rare Earth magnet....... and a superior pinpointer. ONLY perform this in carpets of square-nails........ meaning: high human co-habitation/traffic......with age/era.

For coin hunters:

Dirt era...................... VS......................... types of targets

1850 dirt = .............................................. Half Cents, Half Dimes, Spanish coins
1860 dirt = ............................................. Trimes, 1-Dollar gold coins including Type-1, Type-2, Type-3, Half Dimes
1870 dirt = ............................................. 2-Cent coins, 3-Cent Nickels, Fatty's, Shield Nickels
1880 dirt = ............................................. 20-Cent Quarters, Shield Nickels

((( As time progresses....... I may EDIT and add to this list. )))



Edited 1 time(s). Last edit at 06/18/2023 03:45PM by NASA-Tom.

Fascinating! Hope you will add to the list. Would be interesting to have nail type list with time periods.

I have many sites around the State of Florida...... that I categorize as: RWTG's.
That's = Real World Test Garden's.
Many/most... are carpets-of-nails. Some are DEEP targets only....fairly 'clean' sites. Some have mineral(s). Some have trace-elements of salt. Some may be a variant of all-of-the-above.
Some of these sites may only be postage-stamp size. Say: 7-foot x 19-foot. Each RWTG may present different scenario's. PERFECT for testing new software and/or hardware. ALSO perfect for brainstorming (mild-to-wild) new software and/or hardware......that has never been thought of. When a paradigm-shift ensues...... a new World: opens-up.



((( Then = Retrain-the-Brain...... becomes a requirement ))).

Which leads me to the next sequential topic.

Throughout the Decades ...... I have always wondered: "WHY" do detectors go SO deep in a test-garden; yet, far from that.....in the real-World. =
Example:
If you beat-to-death a certain parcel of huntable land..... with different detectors.....different coils......different programs, different angles-of-approach . , . , . , . , . , . , . , and you 'sanitize' it of all non-ferrous targets. Then..... if you EVER have the chance to take a special detector in to this same parcel of land....... a detector like a Fisher Gold Bug-2 or Manticore with M8 coil and Goldfield Mode......or EQX in Prospecting Mode................,,,,,,,,,,,,,,,,,,...................,,,,,,,,,,,,,,,,,,,................... in short order, you will hear an incredible (insurmountable) amount of tiny flecks/flakes of trash......... that will impede/attenuate the coils ElectroMagnetic energy. If you are hunting with a regular (General Purpose) detector........you may NEVER hear/detect these millions of tiny targets; yet, NEVER think: If I can not hear-it/detect-it...... it must not be affecting the overall performance of the detector.
It DOES!!!! And ....... in fairly severe fashion! (Silent masking).

In one regard......... we have come a long way with unmasking and iron handling abilities. There's been leaps & bounds performed (especially in the algorithm department).......to give much better multi-target separation. DD coils, faster microprocessors, faster clock-speeds, better utilization of frequencies.....to include multi-frequency. , . , . , . , . are a few of the tools utilized. In the real-World............ I see it, witness it, feel it.,.,., and experience it. I'd like to think...... some of my older detectors did quite well in-the-trash; yet, they pail in comparison to today's units. It was aggressively difficult to take my Tesoro, Fisher CZ, DMC2b, Sovereign, XLT ...... and a host of other 30+ year-old units....... into carpets of nails. This is what caused most folks to run FROM carpets-of-nails. Now........ I nearly run TO carpets of nails.,.,.,.,.,., but with a different tool-set.
Today.......... we are now (better) unmasking non-ferrous targets that are at the same level (plane) as nails and other targets. In fact..... we are now JUST starting to ascertain non-ferrous targets just a tad deeper than the 2D plane (same depth levels). , . , . , . , and are slowly advancing further ....... in/with technology. Technologically advanced units like the Manticore with M8 coil, Tarsacci with 11" x 8" coil...... the Deus-2 with 9" coil................... are really good examples of 'advancement'.
We're getting there!

NASA Tom, Your last few post to this Thread are very timely for me as I Have been re-evaluating all of my detectors capabilities in 3D unmasking in Iron and Aluminum trash. So far it has confirmed some things and opened my eyes wider to other aspects.
Using both above ground elevated(1.5") trash & in ground planted (2-3" above a 6" test bed coin) trash, to simulate real world conditions. This helps me to know each detector better & how well different combinations of settings/coils perform.
Coil size matters according to trash density & proximity. Sometimes a smaller coil footprint to get in between the trash, sometimes a larger coil to not be swamped by the trash. Concentric coils often do better than DD coils.
Recovery speed/Sweep speed matters according to trash density also. Sometimes slower Recovery settings give the best audio alert.
There is a lot to learn, know and use to best effect when sites get tough. A large part of my advancement has come though this Forum and your teaching as well as a few other knowledgeable persons in books and over on DP Forum.

Thank you.

Chris

Chris...... you're welcome.

After test-garden validating/testing (and learning)......... and collectively adding this to real-World experience/testing........,,,,,,,,,,,............ you will start to see a pattern of commonalities. Then....... when you hit a new site......... your experience/skillset will .....nearly always..... be spot-on ....to HOW/WHAT types of techniques will work best....... for best results. Even your 'gut' will start to feel comfortable.
(((( Then.......................... you will start to see/feel the pains ....of the 'limitations' of current technology )))).

........A different post segues perfectly into THIS question:

Coil weight.
How many folks would be willing to put-up-with/tolerate a coil that is a few ounces heavier.....that presents better 'depth & sensitivity' performance? OR........ would you prefer a ultra-light coil with a bit less performance?
(((Yes..... 'vague' terms.......,,,,,,,,,, understood!)))

I will choose better performance. I can shorten the shaft a bit if I need to for swing balance.

Chris

I am ALL about performance.
Heck......... I use to swing a CZ-20..... pole-mounted......all day!

I'll take performance all day long for a few more ounces of weight.

Why couldn't we have a higher performing coil thats also lighter weight?

What specifically would make a higher performing coil heavier?

Could the weight be mitigated by using a lighter weight plastic frame or maybe carbon fiber?

Could resin fill for the coil windings be strong and weigh less?

Counterweighting is an option, though Minelab sure made it difficult/expensive to produce an aftermarket shaft for the Manticore (with the "mounting pieces" for both the arm cuff and the handle/control box assembly FIXED ONTO the upper shaft, as opposed to removable, as they were on the Equinox 600/800...)

Steve

Quote:"What specifically would make a higher performing coil heavier?"
It's almost entirely down to the housing - the outer case, foam / resin in-fill , the cable. The copper wire weight is only a modest part of the total, and also, it varies very little with coil size. [ aluminum/aluminium wire could be used, and indeed has been used, but it offers little benefit, and there are technical issues with making good long-term reliable connections to it, plus it has significant thermal expansion/contraction ]
So if you want to make the detector more sensitive to smaller target signals, it will also end up being more sensitive to other unwanted signals. Inadequate mechanical rigidity will allow the housing to flex when bumped against vegetation, sand, dirt, etc. Thermal expansion/contraction/warping will lead to false signals. Electro-static issues, like caused by the coil touching wet grass, will become more significant. Even the 'sag' of the coil, due to its own weight hanging from the lower rod can be significant, especially at the end of coil sweeps, when the swing direction reverses.
Typical methods to reduce these problems involve thicker plastic, larger 'box sections' around the coil, stiffening ribs joining the perimeter to the centre/clevis area, central 'spine / backbone' along the nose-to-tail length of the coil. Many of these have a disproportionate effect. Example, if the 'box section' was increased by 10% from 20mm square to 22mm square, the resin needed to fill that volume would increase by 21% ( 1.1 x 1.1 = 1.21 ). Designers may then choose to make the resin fill 'lighter', using such things as 'syntactic foam' resin, with glass micro-balloons mixed in with it.



Edited 2 time(s). Last edit at 09/07/2023 01:17PM by Pimento.

There is something (a concept) that is much more 'outside-the-box'; yet, your feedback is highly appreciated.

I would lean (no pun intended) for a heavier coil if it meant better performance. In my case I can swing a coil efficiently and accurately with either arm. If one arm gets fatigued, I just switch to the other for a while.

The genre that manufactures have self-incarcerated into.........Mfr VS Mfr...........in competition of: "Who can build the lightest coil".........has really hurt us.
Their thought-process (as of current-day) is: Lighter & better.
The correct thought-process should be: Better & lighter.

In other words: Do not compromise performance ....for lightness.