Big Coils

Took my AT Pro out for 4 hrs of trails, shallow river & river bank hunting with my big coil today . . . what a pain.

Noisy, always 2 or 3 targets being looked at simutaneously, heavy, unbalanced, can't swing that thing in the water,
hard to pinpoint.

Wouldn't it be nice if every manufacturer would learn how to substantially increase the effective depth of their 4", 5", 6"
coils to match or exceed their 10", 11", 12" stock coils. I'm sure it is possible.

I have an old Super6" Fisher Coil for my 1266X (in the shop) that does as good as my new AT Pro 8.5 X 11 Coil.
No joke. Hopefully when my unit gets back from the shop it will do even better?

Yes my 1266X has boost . . . so there's a little bit of apples to oranges with this particular comparison . . . but
I'm sure you can appreciate the basic idea of what I am suggesting here. Just another day dream.

Keep the bell$ and whistle$ coming !!!

Hey but its water proof to 10 ft..... maybe lol.

Dew

I don't think, let's say, a 5" coil of same design can be built to match a 10" coil, for depth. First Texas does build a pretty awesome 5" coil that gets approximately 1 1/2 less depth than their 11" DD coil. I think thats pretty awesome. You could get a F-75LTD/T2SE that have the boost mode, couple that with the 5" DD and you have a very potent small coil rig for your needs. And lightweight to boot.

TerraDigger - That's what I'm talking about . . . just another 3 or 4".
Like to see a quality coil manufacturing only company put something together and
shake things up in this hobby because the Big Name Brand MD Companies are never going to.
They seem to be fixated on bells and whistles that seem to do nothing for depth.
How many different ways do you need . . . to find a shallow dime . . . that a 25 yr. old MD can do
just as well?

My biggest find so far with this hobby is:
How lame ( IMO ) this hobby seems to be when it comes to depth . . . and nothing has
changed yet . . . of course ML Excluded.

Yeah I know depth isn't everything . . . but when the goodies are at 12" and you're not . . . it's the only thing.

"just another 3 or 4 inches" is a big deal and a formatible engineering task.

I don't believe such improvement can be derived by a coil design change alone. If possible, the Big Name MD Companies would have already done it...

The laws of physics are stacked against you, that is the problem.
The ground gives a signal to your detector, because of minerals and microscopic iron/rust content. This signal (in typical ground) is comparable in strength to that given by a dime at 10 inches. So when you scan the 10 inch dime, half of what your detector sees is ground, half is dime. SO it's not too hard to say 'there's something there', but analysing the signal to say it's iron/nickel/dime etc is tough.
Your second problem is the signal from that dime falls away very rapidly with depth. That same dime at 12 inches gives one third the signal it did at 10 inches. So it's harder to say it's there, even, and pretty much impossible to say what it is - 3/4 of the signal is ground, 1/4 dime, net result is an iron signal.

Jim, I'm with you on this one. We've been at 12" on a dime since the late 1980's. A paradigm shift is needed. If only folks could get a taste of what is in the 11" - 16" depth strata........... it would turn the world (and current thought-process) up-side-down. That old statement of: "I'm already digging as deep as I want to dig" ......... would certainly be reconsidered. "Adaptation" we would!

In most cases ......... to get a modern-day detector to detect a dime just one more inch............ is a 64X increase in sensitivity. This puts the unit into excessive EMI/overdrive.

I am absolutely humbled. I am just speaking my mind about what I feel is most important
for me to really enjoy this hobby . . . which is not happening yet . . . and I do not want to let it go.

One person can make a difference, many can cause rapid change, please get on the wagon.

Depth isn't everything . . . but when the goodies are at 12" and you're not . . . it's the only thing.

go-rebels - Fair statement! Might require some minor tweeking?

Pimento - It can be done, without a doubt, with the many brilliant minds in this discipline . . . could
have been done many years ago ( In fact, Fisher has already achieved this to a degree! i.e. Boost )
Instead they focus on whiz/bang/ ding-ding-ding $$$ PROFIT $$$ and HYPE . . . seems to me that
as of 15 or so years ago they have been slowly killing this hobby off by not making meaningful improvements.

Mr. Dankowski - Thank You Kindly.
1" increase requires 64X sens. . . . OK . . . impossible? . . . I think not . . . todays puter power
could probably make that possible . . . maybe plug in a USB 6G memory stick and get as much as you want?
and EMI . . . as they downsize the coil to a 4" or a 5" footprint the resulting EMI has to be much, much less, right?

How does ML do it? I have seen ML's hit tiny buried coins at 18" using a HUGE Coil.
Maybe some of the Nay-Sayers should wrap their head around that?

Here's my best analogy for the problem.
You're sitting at the side of Loch Ness, Scotland, looking for the 'famous monster' to stick his head up out of the water. The problem is, the water is choppy, covered in ripples and waves ( = varying ground signal). If he stuck his head up 6 inches, you would barely notice. If you increased your alertness ( = sensitivity), you would get false signals all the time - just a larger wave, a floating log, a jumping fish. If you use binoculars ( = larger search-coil), again, no real help. The waves appear bigger, he still has to stick his head out a long way for you to see him. You could wait for a nice still day, when the waves are tiny, then you stand more chance. But unfortunately, you can't wait for the MD equivalent (the dirt in your park to become less mineralised).



Edited 2 time(s). Last edit at 05/14/2012 03:37PM by Pimento.

In my mind the Loch Ness Monster, Big Foot and Aliens from other planets do not exist and
the word can't is too easily used . . . and again . . . ML has proven it can be done and to a lesser
degree so has Fisher.

It is just that most MD Manu. Companies have decided this is the way we need to be treated
obviously to maximize profit and it has been going on for many, many years.

What is going to attract new comers to this hobby? Dwindling amounts of shallow clad dropped
last year ( If you are a coin hunter ! Relic Hunters are in a different boat but would still benefit ).

With increased, controlled depth would come increased and deeper VID . . . I would hope?
Wouldn't this benefit all of us?

This is probably a really dumb question.....but is it at least theoretically possible....to construct a shielded coil that could utilize alot more 'sensitivity'....yet not be affected by EMI.....something like a 'focused beam'...or something....to use a real layman's term. Innovative coil design seems to be on the backburner...with the emphasis on software......it seems the CTX may have something 'new' in its coil.....I stated in a earlier post that the real innovations would come in coil designs...this was before this CTX info was out. To me, a engineering noob, that seems be be where the 'real cheese' is at.

TerraDigger - I am by no means educated in MD'g Sci.
I did however do 2 years of Computer Sci. which is now ancient.

So, like yourself, in trying to figure out where the weak links are,
my thoughts kept going back to the coil. It all starts with the coil doesn't it?
You put junk in and you push junk out.

So anyway . . . coil size, coil design, shielding, inner coil windings, TX & RX
and a few other things that have never occurred to me are whats involved?

But even if a perfect solution is created and handed to them on a silver platter
it will never become available, it seems?

Only they can decide when we are to be released from the adolescent strata
level they have kept us trapped in for the past 30 years.

And I have to tell you truthfully, thats exactly how I feel . . . adult priced but
adolescent results. Unless you want to spend Big Buck$.

All I know is . . . I need to go considerably deeper than 6" in the ground and
not deeper in debt for another 6" machine.

Oh and there is one monster I know that does exist . . . that's EMI.
The rest can KMA . . . ( i.e. Kiss My Analogue . . . Fisher ).



Edited 1 time(s). Last edit at 05/15/2012 12:36AM by mcgov51.

A lot more technology can go into the coil............... IF ................ we opt to not make a paradigm shift away from electromagnetic induction balance detection. I mentioned 'smart coils' a few years back (on this forum) ......... and maybe the concept 'might' become employed.

Coils are inductive loops............ not exactly antenna theory; subsequently, do not follow parabolic dish (antenna) abilities. Reflectors/directors/radiating elements/shields ...... hardly apply.

Tom - After TerraDigger contributed his comments concerning shielding I just happen to look at some ML stuff and . . .
I noticed an advertisement from Coiltek for the ML Brand and noticed they emphasized AI for ML MD's. After a closer look
I found out that stands for Anti-Interference. Interesting . . . . . . I'm sure design and a bunch of other things have a lot to do
with it too but . . . shielding is certainly a part of it. Bottom line . . . they already know all about it I'm sure and have decided
many years ago that we don't need stuff that good and besides Taiwan needs the money.

A paradigm shift doesn't look like a possibility in my life time . . . I'm 61 now . . . more like . . . Idem senex stercore.

I did 6 hrs today . . . got skunked . . . not even 1 pc. of shallow clad . . . big state park . . . oh well.
Waiting for Mr. Fisher to get back home from the shop . . . . maybe Oct. ???

I have a hard time believing any detector manufacturer has the ability at present to produce a machine that would get even 2 inches more "useable depth" on dime size targets with stock coil.If they do said machine would sell like crazy even at an inflated price.
Two more inches of depth on a silver dime that IDs and sounds like iron is not going to cut it in my opinion.

Sounds like Bliss Tool is on to something but not a very feasible machine for park hunting if it only discs to medium foil level....

It would be a quantum leap in technology if the Blisstool (or any detector) could ID a nickel or dime as 'non-ferrous' .... at a depth of 14".... here in Florida's inert dirt. This is to include NOT ID'ing ferrous items as 'non-ferrous' (like nails)...... at random/various depths.

Silverhound . . . well . . . who's to say? VLF & PI may be at the end of the rope?

That big paradigm shift Tom always mentions could very well be the only answer to advance this hobby???

I just know that when I use my MD Equip. I don't get any feeling of power or that I am doing anything professional.
Feels adolescent to me . . . now let me remind you . . . I am a coin shooter only so far . . . I' m sure my equip. can hit a
hub cap or engine block at much greatter depths . . . ok.

But I do respect your point and like your use of the term "useable depth".

Glad I started this thread with . . . Wouldn't it be nice if . . .



Edited 1 time(s). Last edit at 05/16/2012 10:59PM by mcgov51.