On my mind -- Random Thoughts

Tom - Yes, it would be an epiphany...and one of your favorite terms - paradigm shift - comes to mind as well.

Marketing reps have long tossed around the phrase "makes your old sites new again," but a laser-focused 2" coil with 8-10" depth truly would.

You have the engineering knowledge, is technical know how to a point where development of a coil like this is even feasible?

Has a coil design like this possibly been retarded by its lack of mass market potential?

NASA-Tom Wrote:
-------------------------------------------------------
> * Another thought: What if we had a two-inch ( 2"
> ) coil that had nearly all of the electromagnetic
> field-intensity energy directly under the coil
> (minimal side-splatter) ...... and it had 8" - 10"
> depth capabilities on coin-sized
> objects.,.,.,.,.,.,.,.,. to be used in trashy
> areas. Do you think this would startle/open some
> eyes (epiphany)????

I think that this is possible with a larger stock coil, my old analog 5900 CB in all-metal mode can be manually re-tuned to narrow down the edge sensitivity of the stock 9½" coil. By continually placing the hot spot of the coil just off target and releasing pinpoint trigger and reengaging the pinpoint trigger it will narrow the signal down to a coin sized signal.Therefore it would seem feasible/doable in the circuit design.

Mike Hillis--That Garrett coil that only detected on top was called their"double stacked" coil. It came out in the early or middle 70's and was super deep. As soon as it came out I got one and went to a barbed wire fence line that I couldn't hunt before and dug a number of 3" Hotchkiss shells that I knew was there,but had been unable to hunt. The first "double stacked" came out on the famous "orange head" Garrett that was/is the deepest Garrett ever.

Hi,,,there already was a 1" coil made in the past so it's something that can be done.........JJ

I'm not smart enough to comment on this.I will leave it to the electronic ''expert's''.

One of my best MD finds: this forum!
First visit, I sensed it was different than all the others. And some of the members seem to be really different <g>, mostly in a good way.

Don't really like seeing comments that demean some of our largest contributors because they test for, or have ties to one manufacturer or another. Free speech, yes, but at what price to the exchange of info here?

Lots of experience and expertise here. I take what I can use and apply it to my own conditions and pursuits. Hopefully I contribute to others once in a while.

I like to see the noise factor low and the (MD) intelligence sharing factor high.

I think it's helpful when posters sign their posts with their (first) names. Helps me when somebody replies to (name) and I can figure out who they are replying to <g>.

Tom should give up his day job and just detect and teach (here, for free <vbg>). Nah, I know he can't do that, but I am grateful to him for sharing his knowledge, insight, and HUNGER for technological advancement. Thanks, Tom!

Wouldn't it be fun to travel around and get out detecting with others on this list in their natural habitat? Well, in a sense, this forum permits us to do just that (lightbulb!).

As one of advancing age, I offer the proposition that ergonomics, i.e., weight and balance is getting to be MORE important than separation and depth. Why do some manufacturers not understand this? Said tongue in cheek, but still...

All detectors should offer the option of wireless headphones!

Why can't a detector, instead of saying something like fizz-pop-crackle, say "large iron at 8 inches"? Instead of nehhh, say "probably a nickel at 6 inches"?

Why not have a compound coil design offering large search coil and smaller "sniper" coil combined, and thru 2 cables and/or switching mechanism in the control box, select the desired coil configuration on the fly?

Detectors differentiate based on conductivity and size? What about density? Understood that any and all characteristics are shared by desirable and undesirable targets.

It stands to reason that an entity that manufactures only coils puts all resources toward producing coils. You'd think their coils would be superior to OEMs. But are they?

Given a choice between more profit and better performance, what choice will a company make? I think I know the answer.

Thanks to the guys that buy and try. You sure keep things interesting here.

Pleasant Garden, NC
AT Max, Nokta Impact, MX Sport, Nokta FORS Relic, GPX 4800, Infinium, Racer, Deus, F75SE, Nautilus DMC II (order of acquisition, last to first)

Does an archeologist argue with a plow? A bureaucrat with a bulldozer?

The trx can hit a coin at nearly 4'', so why not?

Thanks Doc,

Magnetic flux is different than most energy we are used to. Unlike light and sound, It can easily travel through most objects, yet the introduction of iron can obsorb it, diffuse it, even redirect it's energy at a 90 degree angle. Magnetic flux requires a fixed point for both ends. However, knowing that, if you could somehow disconnect one end and control the direction of its release before reconnection occures, you could achieve what Tom is dreaming of. A focused, you couldn't call it a beam, more like a whip, direction of travel that could be directed for some maximum distance.

There are multiple ways of getting an alternating magnetic field into the ground. You could spin a bar magnet, or electrical magnet on its axis and approach the ground like you were cutting a board. You could use a vertical reciprocating rod, and approach the ground like you pounding in stake. All kinds of ways to approach that particular task. You could still create your null and read returning phase responses. For what ever reason, we do it with a horizontal coil of wire.

Tom has been looking at his rare earth magnet for quite some time now.

HH
Mike



Edited 1 time(s). Last edit at 01/23/2015 06:28PM by Mike Hillis.

Is there a computer program that exists that can simulate the magnetic field from a complex shaped transmitter (ring coil) as how simulations are done for airflow around a wing or stress distribution in a loaded mechanical part? Doesn't there exist a mathematical formula that exactly predicts the field around a simple straight wire or point source?

Such a program could be used to exactly answer this question.

To create/invent something that conceptually does not exist yet........... is one problem.
Then.......... to "realize" (validate) a market for it............ is yet another problem.

---------------------------------------------------------------------

What if this decades-old 'mindset' is totally wrong.
We have been using TR / IB electromagnetic detection devices (on a magnetic/electromagnetic core Earth) (((seems counter-productive/counter-intuitive))) for soooo long. Is there not another form of detectablity? (Yes..... paradigm shift).

We are (self) incarcerated into 'near-field' limitations.

NASA-Tom Wrote:
-------------------------------------------------------
> * Another thought: What if we had a two-inch ( 2"
> ) coil that had nearly all of the electromagnetic
> field-intensity energy directly under the coil
> (minimal side-splatter) ...... and it had 8" - 10"
> depth capabilities on coin-sized
> objects.,.,.,.,.,.,.,.,. to be used in trashy
> areas. Do you think this would startle/open some
> eyes (epiphany)????


I would think that a small 2" coil would drive a lot of people CRAZY lol. Although I feel that if there was one available and someone took their time, it would take a lot of time to cover ground efficiently now, there would be great finds made with it. I've really had my mindset changed on the covering ground concept vs actually getting what was there to begin with that was not being seen. Even if a coil that size would only get a depth of 4 inches it would be a game changer. It's human nature to want to go to the races when you can win the race by not hardly moving at all while detecting. Rabbit/tortoise kind of comes to mind. The arm's would get the workout not the legs. Now someone give us a 2-3" small hockey puck please..........

I eould like a 2-3" coil,but in a 5"housing...it would be esdier to swing,in my mind. paint a ring on top to visualize actual voil size. Hey Nokta,you reading these???

What if we had a two-inch ( 2" ) coil that had nearly all of the electromagnetic field-intensity energy directly under the coil (minimal side-splatter)


Obviously there is no such thing as a magnetic monopole, the field lines cannot be shot into space like an electric field can. All field lines must return in a circiut to the opposing pole. But you can channel the field lines so that they are more concentrated (which is sort of the idea of the chiseled shape of the DD coil) down the centerline.

Ferromagnetic materials channel magnetic flux such that by decreasing the cross-sectional area of the flux path you correspondingly increase the magnetic flux up to its saturation flux density.

Next, design the flux concentrator such that the concentrated flux can be controlled; the field pattern can be changed. Then you have to be concerned with eddy current and hysteresis losses which depend upon frequency used and flux density changes within the concentrator. Then it gets complicated.

Probably the end result would be some kind of lamination coil-like configuration with high saturation flux density and releatively high permeability that can channel the flux effectively. Then you have to consider cost and durability.

So, get to it.

With a 1"or2" coil would be like hunting with a pinpointer. You could just craw on you knees and dig holes. I dont think i would like that. It would be better to just dig all hits.

Take off your coil and install the inline probe on the end....reads on the detector screen.

I have actually done this with the sovereign and s-1 probe! Cut out a big one square foot flap of turf at the Wino park I mention,and use the probe...hey,it worked!

Flintstone Wrote:
-------------------------------------------------------
> With a 1"or2" coil would be like hunting with a
> pinpointer. You could just craw on you knees and
> dig holes. I dont think i would like that. It
> would be better to just dig all hits.




The Garrett PP is about 3/4" circumference at the tip, so a 2" coil wouldn't be that extreme. But it sure wouldn't be the coil for one of those days when you want to enjoy detecting with a minimum of concentration.

In the appropriate location, where heavy masking is present, that 2" coil would see many targets that a 5" coil will not. Just like a 5" coil will see many that would be masked by a 11" coil.

A 2" coil that could even get depth similar to a Compadre, 5" or so on a dime in moderate soil, would be a major breakthrough. 8-10" as Tom described...detecting nirvana.

This would obviously be a specialty type coil, and it would necessitate a significantly more patient and deliberate detecting method. The vast majority of square footage in the world would not be well served by this coil. Like painting a house with an artist brush.

But there are many areas, old areas, so-called "hunted out" areas, that a coil like this would excel like nothing ever seen before.

Detector unmasking advancements have led more of us to seek out high trash, iron-laden (i.e. high human activity) sites.

I have no doubt that a 2" coil with serious focused depth and accurate discrimination = paradigm shift. The amount of additional targets that could be found in certain locations would be phenomenal.

As others have said a million times in this thread, this is the best detecting site out there, for a fair, unbiased, open exchange of information and knowledge. First and foremost, by NASA-Tom contributing and setting the tone, and followed by all the other brilliant minds here who also happen to be avid detectorists.

THANKS to all!

Steve

If someone could design a way to detect deep with a very small coil everything will change.

The 5 " Razorback on a TDI can do some suprising things some places. F75, V3i and Explorers opens up in a new way to when using small coils.

If the coil is small enough and deep enough you can tilt it to look under shallow unwanted trash.

Agree. A 2" coil would (initially) draw a unique/niche market. If that 2" coil could detect a dime to........... say 17" deep............ and folks were to take this detector & 2" coil to "completely hunted out" sites............ the 2" coil would give the initial illusion of "intimidatingly insufficient EFFICIENCY" ..... due to tiny size.......... vs........... area to be covered. But............ once this 17" capable unit was put into operation..... within the first few minutes; folks would be surprised (enlightened) as to how many targets exist on a vertical (depth) axis.............. subsequently, would then have appreciation (and understanding) as to 'why' a 2" coil would be quantified/qualified/justified/needed...... due to dense adjacent target separation requirements.

((( No........ with current-day technology.......... it is not possible to have a 2" coil ascertain 17" depths ))).

NASA Tom >>((( No........ with current-day technology.......... it is not possible to have a 2" coil ascertain 17" depths ))).

I'd do back flips if a 2" coil would get half that.

((( Steve...... agree ))).

* Encroaching a decade run-time of this forum, I have concluded:

1) The nominal/median average member on this forum .... owns 7 detectors.
2) This forum retains the top 1% technically-minded, dedicated, mono-maniac, burning-passion detectorists on this planet.
3) Retains the highest percentage of 'niche' detectorists (of which lead the marketing 'direction').
4) Disputably retains highest academic members (by volume & ratio).
5) Highest ratio of hunters that deliberately seek out & hunt carpets of (old) nails/iron.
6) Most disciplined/self-policing, VOCAL, freedom-of-speech members.
7) Highest generated rate-of-trust whereby, members will freely ship detectors/equipment to other members (blind risk).

Summation: A very unique bunch of folks..... to the point of "bloodline-family" protection.
Yes, it would be priceless if all of us could hunt together........ or at least have a convention-reception.

Well what are we waiting for--Florida has good weather this time of year and Tom how many did you say you could sleep on the floor??

doc holiday Wrote:
-------------------------------------------------------
> Well what are we waiting for--Florida has good
> weather this time of year and Tom how many did you
> say you could sleep on the floor??

lol, That's too funny doc, My wife is asking me what I'm laughing at...The picture in my minds eye,, Tom explaning to his wife the goings on while were all getting setteled on his hardwood floors for the night. Hundreds of detectors leaning up all over the place, socks tucked into smelly boots, omg lol.

Ok - if old stuff is very deep then at some point getting the good stuff would become impractical. - is there not a bouncy factor (at some point the coin reachs equilibrium with the soil around them) and they stop going down.

Maybe we could make deals with escavating companies - they take that dirt somewhere may be interesting to check out if they would give us access.

We have an old golf course converted back to a park. Not sure how long it was a golf course but let's say a very long time. Most of the good stuff (silver) is about at the edge of what I was using 10 to 12 inches (I was maybe 8 to 10, but a guy with CZ3d was killing it about 10 to 12) so I am betting there is even better stuff at 12 to 16 but to me that stuff is invisible.

***Does anyone really want to dig 16 inch holes?***

Bryanna - Nebraska

Current - New to me but not new MXT Pro and T2 SE2 - Previous Minelab Sovereign GT, Minelab Safari, Whites DFX, Whites Eagle Spectrum
Smile its a good for you!



Edited 1 time(s). Last edit at 01/27/2015 11:29AM by Bryannagirl.

Absolutely. In a heart-beat. If you get a chance to talk to a Archaeologist....... the education would be 'enlightening'. ((( Understatement! )))
In general..... the deeper you go...... the more value/history.

Bryanna, Ive actually done that. A landscape company removed soil in a park...I pulled my dump truck up,and hauled it for them...found common silver. Also,we have followed trucks to find where they dumped dirt that was excavated.

NASA-Tom Wrote:
-------------------------------------------------------
> Yes, it would be priceless if all of us could hunt together........ or at least have a convention-reception.

Not out of the question! The treasuredepot has their annual hunts (civil war sites), why not us??

Im in!

Hi,,,,I can't help wondering if I fall into any of them numbers on Tom's categorical list????..JJ