On my mind -- Random Thoughts

I believe it's possible, we just don't know how to make it happen yet.

I can see this happening to some extent right now with the GPX. Some of the timings and other adjustments make iron react differently. I change timing quite often depending on what targets I want to find or ignore.

I believe the PI has the greatest chance of achieving this.

Iron is a unsuspecting, multifaceted problem(s), multiple-order-of-magnitude, crippling signal-strength = handicap. For instance: just a small piece of a nail will cripple most of the depth of a detector...…….. unknowingly/unsuspectingly. Not to mention...….. killjoy any form of ID... from any non-ferrous target in close proximity....to a piece of a nail. The signal strength of a small piece of a nail..... is MUCH stronger than ….. say..... a dime. And...…. the small piece of iron will stay 'lit-up' for many, many times longer than any non-ferrous target. I could never semantically convey JUST HOW CRIPPLING iron truly is. Summation: Iron poses many times more than just one problem.

A fast recovery microprocessor does not alter the basic fundamental physics principle that: all coils emit magnetic energy... into magnetic dirt... with magnetic nails. . . . . . . . . . AND …...iron will stay 'lit-up' for many, many times longer than any non-ferrous target could ever generate. A 'fast response' detector does-not/can-not circumvent physics.

Today...… a few flavors of detectors can ………. say...……. see the 80% signal-strength of the nail (20% signal strength from the coin)………..,,,,,,,,,,,,and keep the audio-gate open...….. and give a blurred/smeared "both target" audio. Some detectors can even squelch-out some of the iron audio response..... to give a cleaner non-ferrous target audio report; yet/...…. BUT...….. do NOT circumvent the masking of the iron...…… nor can detune the actual signal-strength of the iron. This is to say: The detection depth performance loss... of the non-ferrous target...… can never be restored... whatsoever.

What kind of non-magnetic field detector could see thru iron?

Rick...… that's just exactly the challenge/opportunity.
---------------------------------------------------------------------------------------------

The pinnacle method for the detection of a magnetic nail..... is ……. magnetic energy.
So...………… "WHY" are we using magnetic energy to detect NON-magnetic coins/jewelry/relics.
The LAST thing you want to use.........to detect NON-magnetic items...….. is magnetic energy.
---- Not only does magnetic energy accentuate-and-amplify the detection of ferrous targets………(((intensely masking the non-ferrous targets)))…….. but...… it ALSO has extremely low detection of non-ferrous targets. . . . . . . AND...…… magnetic energy is heavily attenuated by magnetic dirt. (Oxides of ferrous..... of which.... much of this core ...and the Earth...is covered in).

We put SO much focus/energy/time/labor into Simultaneous Multi Frequency and Pulse Induction format. Yet, ………... the BIG picture is............…both operate on the principle/methodology of 'magnetic transmission-detection'.



MORAL OF THE STORY: IT'S HARD TO BREAK FAMILIAR "COMFORT-ZONE" MEGA-FOCUSED MINDSET.

Magnetic detection of objects would still have its use, though. If you had a non-magnetic sensor ( ultrasonic, whatever tech ), it would see all objects, iron and non-iron alike. So a magnetic detector would still be useful to determine if single finds were ferrous/non-ferrous. Not much use in iron-contaminated ground, though.

((( Motive: ----- Enabling = THOUGHT )))

And if you knew fairly accurately where an item was, you could examine it using 'less convenient' methods. I've mentioned in the past my interest in 'insertable' probes along the lines of the Ott Periscope Probe, and I do have some part-completed experimental bits and pieces. Obviously only useful in very soft ground - but that's the nature of the hobby, working with the seasons.
We are having a wet season here in the U.K at the moment, and I have been thinking about this probe again, eyeing up some glass-fibre and carbon-fibre tubes in my 'workshop'. In my location, there are a lot of stones in the soil, which are trouble when digging, and not what is wanted for probing, unfortunately. So the probe would have to be rugged.

Magnetic field is easy to create. Hard to think outside of the box.

Sound/ultrasound ….. is one (of many) options. Sound is interesting because: There's a different return signal of sound/ultrasound from a rusty nail..... as compared to a non-rusty silver coin, gold ring, lead bullet. Returned sound from a rusty nail.... is more smeared/blurred. Sound from a coin is very solid. (((But...… sound returned from glass..... is also very solid))). And rocks are very low density......as compared to a coin/ring/bullet; hence, rocks produce a low return audio. Yes……….. technology exists to employ returned Sound Discrimination/differentiation.

Remember: Sound is merely/simply ONE option..... (out of many other methodologies).
((( It is difficult to think-outside-the-box...….. especially after playing inside one particular box for 78 years ))).

I was going to suggest ultrasound. I know a guy working on ultrasound right now. Tom you probably know who I'm referring to.

(((I can think of two...…. [[and unrelated]]...… both with fairly serious intent))).

NASA Tom, after you made the comment about ultrasound it got me thinking about the guy I know who is perusing this method of detecting metals and other objects in the ground. I find it interesting that major manufactures of metal detectors still continue to try to squeeze more out of VLF technology (which appears tapped out) rather than look into new or different technology. Maybe I'm wrong, maybe they are. But, what direction do you see manufacturers going forward in? What direction do you feel they should be going in? What does the future hold for us?

Andrew...….. I WILL get to your questions...… when I have appropriate time to PROPERLY answer your questions!

Timing is apropos. It would behoove all of us (right about now) to re-read page 5 of this very thread...… with posts made on May 27, 2015.

Andrew...…. I'm going to have to do this...… incrementally.

First...…. let me premise with this:

It was around 1970. Rolex held just over 70% of the watch-industry: money on the table. Their watches had the most precise cut jewels/gears ever known to mankind. Their accuracy was second-to-none. Rolex dominance!
Enter a World trade show.
A booth next to the towering Rolex booth...…. sat a man with a small plastic watch...… with numerals on it. Rolex laughed at his idea.... for the entire tradeshow.
In the next few (short) years...…. the battery-powered digital watch DOMINATED. And...… by the 1980's...… nearly everyone owned (in one form or another)….. a inexpensive digital watch that was MUCH more accurate than a mechanical Rolex could/would ever be.
NOW........Mr. Casio was laughing ….. all the way to the bank...….. as he DOMINATED over 90% of the entire World watch industry. Rolex had been reduced to (just under) 3% of market share.

For Rolex...….. a unexpected (technological) paradigm-shift swept them off of their feet.

(((Now I can talk about metal detectors..... and the future thereof))).

I've heard that ultrasonic subterranean imaging can identify targets down to about 0.20 inches in size using ~300kHz frequency, losing target resolution to about 12" at ~8kHz. So, perhaps someday. But for now the cost, weight, power needs, and I think the technical difficulty of locating and identifying targets using sound makes such a device impractical for hobby use.

Humm.... Nullum gratuitum prandium (no free lunch). It appears to tell me.... the best use of a disc PI would be reverse disc. Hope those arent plastic knob switches lol.



Edited 1 time(s). Last edit at 10/23/2019 12:18PM by dewcon4414.

Andrew...… I have a little time...…. and will answer (only) your first question: "What direction do you see manufacturers going forward in?"

So far..... we have seen fairly rapid advancement...…. within the past 12 years...…. in the metal detection industry. We now have elliptical shaped DD coils...… that present much better/enhanced adjacent target separation characteristics and with a bit better mineralization handling capabilities. We now have much faster clock-speed microprocessors/microcontrollers. We now have better/faster filters. Recently...… we have been able to incorporate all of this into the (use-to-be: slow) simultaneous multifrequency platform. Improved ID at depth. Lighter units. More LCD utilization. Longer life rechargeable batteries. Bluetooth. More hyper-gain units. ======= And all of this has happened at a much faster rate....than ever before; yet,...…….. no where near as fast as the rest of the electronics industry (cell-phones, GPS, drones, computers...…..etc...………. and not as fast as some of us wish.

I see Mfr's going forward/advancing in 'all-of-the-above'...… to greater plateau's. Yes, there is a lot of 'copying'. This is a double-edged sword. It is flattering when someone copies you; yet, it also means that they have nothing new that is out of their own intuitive cognizance. Innovative engineering intuitiveness is a 'needed' (and rare) talent …… that most metal detector Mfr's do not have. For instance: I am VERY concerned about White's engineering staff. If you have a weak engineering staff...…. it is hard to see this......,,,,,,,,, especially from the 'inside'. You can not 'correct' something...that you cannot see. It can also be a little difficult to see in your corporate metrics.. . . . . . . . until its too late. Human Capital is your number one asset. A Chief Design Engineer holds the entire company, future..... and existence..... of the entity...… nearly solely in his/her hands. A superior Marketing Dept can only do so much..... and only for so long.
I also see our current-day Mfr's continuing to move forward...….. incrementally...…… in a evolutionary process.,.,.,.,.,.,.,.,.,. still within the confines of magnetic/electromagnetic methodology. ""We've been doing it this way for 78 years.....and it works. Why should we change"". . . . . . . is an ALL-TO-EASY mindset..... that will eventually backfire. With guarantee absolute. When a human becomes 'fixated' on something...….. there is no 'outside-the-box' thinking ability. We can all make excuses for other conceptual notions that: "That would never work"...…………. to the point of quantifying, justifying, qualifying ...said statement.
We never thought we would have our own personal communicator...… like Star Trek. We never thought we could ever put a man on the moon.
((( I predict roads/asphalt will no longer be used...… in about 20-years. Who could ever imagine! ))).
Twenty years ago..... I predicted "quad-copters" (today...… called: Drones)…… would be delivering FedEx/UPS/USPS/DHL packages to your front door. ((( I have been slightly off... on my timing ))).
Mfr's continue to forge forward..... in a continuing evolutionary process.

LOVE: BITES. WATCH OUT!

More to follow.

Off subject; yet,,,,,,,,,,, on my mind.

When you choose a detector...…. or a Mode...…. or a Operating Frequency...……,,,,,,,,,,, there is a hidden, unsuspecting danger. You may be a gold prospector...………..so...…….. you choose a detector with a very high frequency (or you select the highest frequency of the detector that you have...…. if it has selectable/adjustable frequencies). In theory; this is correct.

In reality: Here is the trump-card (and should be your new thought-process) =

MINIMIZE ATTENUATION! Choose a detector/frequency/Mode that is LEAST attenuated/effected by the dirt in which you choose to hunt. All-too-often...… you choose a very high frequency to go prospecting with. This is perfect...…,,,,,,,,,,,,. . . . . . . . for air-tests! BUT...… the highest freq may be fully attenuated (eaten) by the bad dirt. The lowest frequency seems like your LAST choice..... that you would ever select/pick...for gold prospecting; yet, you may find that ……. even though it is the least sensitive to gold nuggets...… it may be the only freq/choice that punches into the dirt..... with minimum attenuation.

TAKE-AWAY: Always choose a frequency(ies) that FIRST takes into consideration: attenuation...………………………………………. then...….. secondarily: resonant to the type of target(s) you choose to find.
Choose wisely!

Tom-Thank you for taking the time to answer my questions, I know you are very busy and I appreciate the knowledge you share on this forum.

I worry about White's as well......I grew up detecting with multiple White's machines........they used to be great! But IMO they are way behind the times now. I quit using them the day I bought my Fisher CZ 6a back in the 90's and haven't looked back. Borrowed a few from friends in the past........the XLT and Eagle Spectrum but was far from impressed with either of them. Part of that is my bad dirt here.

Just seems like there should be a way to see between all the iron to locate the good targets below with some kind of technology. Even if a person had to move real slow to pick between nails and such it could pay off big. It would require a small laser like concentrated field that could both see deep and narrow at the same time. Probably not possible but I can always dream.

I also wondered about PI's, I have a general idea of how they work with the delay and all and how that can be manipulated to ignore certain types of metal or sized objects. Seems like there should be a way to shoot multiple pulses into the ground at different delays and then take that data to be able to discriminate or ignore certain targets. Maybe that's what Minelab is already doing with the GPX, IDK I'm not a engineer so I could have it all wrong.

I have been doing a lot of thinking outside the box the last few years.....trying different machines......different frequencies......different modes......hunting different areas and digging different signals other people don't. It's paid off for me I've found a lot of good finds doing this and I plan to do more in the future.

I have always liked the Whites MXT. Analog; yet, hair-splitting capabilities ….like a digital platform.

Andrew...……. the elliptical DD coils come closest to 'laser beam' like ….. knife-cutting 'narrow' field footprint(s)….. that you quest. Problem is...…. even if you have a non-ferrous target directly underneath the beam of the elliptical DD coil; yet, there is a piece of iron in (somewhat) close proximity of the coil...…. the iron will 'light-up'...… stay 'lit-up' for much longer than the non-ferrous item...…. bleed and attenuate the electromagnetic energy...…… and make a masking electromagnetic footprint that is MUCH bigger than the actual iron item...... with a large, encompassing electromagnetic plume/surrounding-halo that can be much larger than the coil...….. presenting a broad-area masking electromagnetic blanket.

Also...………….. when a Mfr is wanting to jump onboard with their own version of simultaneous multi-frequency...….. they are (most probably) a 'follower'. Following in the path/footprint of someone else's idea.... that has had success with SMF.
To "think beyond"...… is a difficult thing to do. To think 'outside-the-box' is a difficult thing to do. To create your own format (platform)……. that does not yet exist...………,,,,,,,,,,,,,,, is a difficult thing to do.
Yes, over 95% of inventions..... are merely REinventing the existing wheel. . . . . . . . . . . . . . . . . . . . . . and may not be a total bad thing; yet, in this case...… would still be using magnetic energy,,,,, in magnetic dirt,,,,, with magnetic nails: with the end-resultant of masking the intended non-ferrous targets of interest.

Tom, my thought is that swinging a little coil on a stick isn't going to go any further than it is now. Computer technology has advance to the point where the logical next step is large area coverage. Think PI grid mesh consisting of an X number of coils ( the old bed spring ) blanking the ground beneath in various pulse delays, building up a 2D picture of pulse delay and signal strength responses. Think focus within the grid of both delay and power on specific targets or areas. Go ahead and group null the grid mesh coils and throw in some VLF.

I lay the grid. Take my PI shot consisting of low to high or high to low pulse delay sequencing, let the software run, review the results, Focus on specific areas of interest by enabling or disabling different sections of the grid mesh. Maybe even shift the grid over a few inches to get a different look. Maybe hit the high interest responses with a vlf shot for a phase shift number, id the physical grid number and then walk over to that grid on the mesh and recover the target. Shift the grid mesh coil over and repeat.

shoot....make the coils of the grid snap fit so you can snap build the PI grid mesh around trees, large rocks, bushes, etc.

Could probably cover the same amount of ground with a PI Mesh Grid as you could sweep it.

My gold nugget.

For sharing my genius I get the first viable production model and any upgrades for free if any mfg makes this device.

HH
Mike

NASA-Tom Wrote:
-------------------------------------------------------
> Andrew...…. I'm going to have to do this...… incre
> mentally.
>
> First...…. let me premise with this:
>
> It was around 1970. Rolex held just over 70% of th
> e watch-industry: money on the table. Their watche
> s had the most precise cut jewels/gears ever known
> to mankind. Their accuracy was second-to-none. Ro
> lex dominance!
> Enter a World trade show.
> A booth next to the towering Rolex booth...…. sat
> a man with a small plastic watch...… with numerals
> on it. Rolex laughed at his idea.... for the entir
> e tradeshow.
> In the next few (short) years...…. the battery-pow
> ered digital watch DOMINATED. And...… by the 1980'
> s...… nearly everyone owned (in one form or anothe
> r)….. a inexpensive digital watch that was MUCH mo
> re accurate than a mechanical Rolex could/would ev
> er be.
> NOW........Mr. Casio was laughing ….. all the way
> to the bank...….. as he DOMINATED over 90% of the
> entire World watch industry. Rolex had been reduce
> d to (just under) 3% of market share.
>
> For Rolex...….. a unexpected (technological) parad
> igm-shift swept them off of their feet.
>
> (((Now I can talk about metal detectors..... and t
> he future thereof))).

I think you may have some details mixed up. The quartz crystal watch is what killed the mechanical watch industry. I believe it was invented by the Swiss; but, the Japanese ramped it up to a worldwide commercial scale.

My father had a Bulova watch back in the early 1970s with a tuning fork logo on the face, presumably representing the vibration of the quartz crystal. A flood of Seiko watches hit the market a few years later.

Bayard...…. absolutely! The P.L.L. quartz crystal was certainly a big part of the picture; yet, when the LED (and subsequent LCD) digital ….came out...…. it flipped the watch industry up-side-down.

Mike …… sounds like a very large multi/co-phased coil(s)...… that all must be nulled unto each other. Sounds slightly cumbersome.

Quote Bayard:"My father had a Bulova watch back in the early 1970s with a tuning fork logo on the face, presumably representing the vibration of the quartz crystal"
No, they actually had a mechanical tuning fork inside, kept oscillating with a wire coil placed near the tip of one 'tang', driven by a simple one-transistor oscillator circuit. The vibrating fork was connected to a tiny escapement, featuring a gear-wheel about 2.5mm (0.1") diameter, with 300 tiny teeth on it.
They pre-date quartz watches by many years. And they are very collectible today, especially those from Omega. Parts are unavailable, so 'lesser' watches get stripped to keep prestige models going.
Some background reading:
[monochrome-watches.com]

A friend has a faulty Tissot tuning-fork watch, which he wanted to get repaired. He was informed it wasn't economical to repair, but was offered a surprising amount for it, simply because it shared a mechanism with an Omega.



Edited 3 time(s). Last edit at 10/25/2019 09:24AM by Pimento.

As a side-note...……. before I answer Andrew's remainder two questions...…….. I know of an individual of whom is experimenting with ultrasound. The contraption has a unique looking phased-array of transducers mounted on a polymer plate. Heavy ….. but functional. His high-frequency attempt resulted in tremendous target resolution; yet, almost no depth (due to attenuation). The power supply was a wired/external motorcycle battery. Now...…. the power supply has been replaced with a onboard ganged (4) 26650 Li Ion battery pack. The weight of the contraption....is almost as much as a CTX-3030.
Since then...…. he has now ridded the phased-array transducer pack...…… and has replaced it with a electronically controlled truncated (variant) of an adjustable wide-span oscillator...…. for audio spectrum sweep..... and control. Lower freq's are punching much deeper...…. with fairly good resolution.
The claim: He hates himself...…. because he can't think far enough outside-the-box. Incarcerated within the confines of his own mental prison. ((( Yet...….. I know...…….. he has indeed....come a long way outside-the-box...…….. ,,,,,,,,,,,, and with some measurable/value-added revolutionary success. )))

Pimento Wrote:
-------------------------------------------------------
> Quote Bayard:"My father had a Bulova w
> atch back in the early 1970s with a tuning fork lo
> go on the face, presumably representing the vibrat
> ion of the quartz crystal"
> No, they actually had a mechanical tuning fork ins
> ide, kept oscillating with a wire coil placed near
> the tip of one 'tang', driven by a simple one-tran
> sistor oscillator circuit. The vibrating fork was
> connected to a tiny escapement, featuring a gear-w
> heel about 2.5mm (0.1") diameter, with 300 tiny te
> eth on it.
> They pre-date quartz watches by many years. And th
> ey are very collectible today, especially t
> hose from Omega. Parts are unavailable, so 'lesser
> ' watches get stripped to keep prestige models goi
> ng.box of old watches I have
> Some background reading:
> [monochrome-watches.com]
>
> A friend has a faulty Tissot tuning-fork watch, wh
> ich he wanted to get repaired. He was informed it
> wasn't economical to repair, but was offered a sur
> prising amount for it, simply because it shared a
> mechanism with an Omega.

I'd better check the box of old watches my dad left me. Pimento, what's a good way (site) to find out the ones collected.?

I'm no expert on these watches, unfortunately.
I suggest a Google search for 'tuning fork watch' should give some useful leads. And searching eBay's watch category for 'tuning fork' , hummer, f300 , Accutron should produce plenty of relevant results.

(apologies for off-topic horological chat)



Edited 1 time(s). Last edit at 10/25/2019 09:43PM by Pimento.

This is a very interesting topic that I have enjoyed following. I do not post much, but recently I heard a news story on the radio that caused a light bulb to go on, so I decided to post. The story was about the rapidly expanding field of data analysis. New digital technologies have resulted in a flood of data that is so immense that it is impossible to process manually. One of the examples given was the use of neural network technology to comb through hundreds of hours of digital recordings to pick out elephant sounds from all of the other noises present in the jungle. The neural network (NN) is a computer program of sorts that is "trained" to recognize a desired sound, image, or whatever. Once trained, the NN can pick out elephant sounds from recordings in a fraction of the time required for manual analysis. A similar process can be carried out for images. The second example given on the show was picking out certain types of images, in this case images of dogs. How does one go about telling a computer how to pick out traits that are unique to dogs. The beauty of the NN is that the system learns to identify dogs on its own. One simply trains the NN by presenting a training set of "dog" and "non-dog" images. Some of the attributes that the NN picks up on are often not intuitive at all.

So how does this relate to detector technology? What if a metal detector could be fitted with neural network technology and trained to identify various objects? The NN could have not only the phase of the return signal, but a whole host of other data that could be processed in a fraction of a second. The signal could be processed from multiple separate frequencies. A weak or scratchy response in high frequency paired with a solid signal at lower frequency could be interpreted as a bottle cap. This could be confirmed by any number of other data. The NN could evaluate the signal both on the approach to a target and following the target (i.e. edge information) in all metal and individual frequencies. What might take a user 30 seconds or more to perform by switching modes, etc. could be done instantly. A detector could be trained to operate under specific soil conditions. I know, this technology is probably not advanced to the point where it could be miniaturized into a ~3lb package. The way technology is moving I think it is possible that it could be achieved one day. This idea is only conceptual.

Nasa-Tom : In-so-far as iron see -through (to combat masking), where does the Compass 77b fit into all this discussion ?

You could lay 2 or 3 nails (depending on size) right over a coin, and still get the coin. But if you scanned those same 2 or 3 nails solo, you'd get a null.

1) Granted, by the time you added the 3rd or 4th nail, the trick began to wain.

2) Granted, you lacked any other form of ID (foil to silver dollar all sounded the same)

3) Granted, it lacked ability in nasty minerals.

4) Granted, it probably only went 4 or 5" on a coin sized object, with a tail-wind.

5) Granted they were a bear to keep balanced.

A Tesoro Bandito comes *sort of * close to this ability, but ... not quite. Yet is easier to handle.

Seems to me that the 77b could be brought back in a modern package.

They tried with the "Legend" in the 1980s. But that attempt was fraught with problems....