GPZ 19" Coil

Anything above 1mm thickness,just adds more unnecessary weight,to a coil that's already heavy guy's. Try keeping the Lexan sheet to 1mm or below in thickness.

Cheers Kon.

Jen58 wrote:http://www.ebay.com.au/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=291791498259&_sacat=0


I have also seen the same sort of thing in bunnings

Thanks Jen, I'll learn how to do that one day, I promise.

One ML dealer is offering to chuck in a skid plate for free for the new 19" if purchased before a certain date, I wonder how much the skid plates are to buy?

cheers dave

[quote="kon61"] "FOREINER" Lyrics (slightly modded to suit me & my coil).

So long, I'v been looking too hard,I'v been waiting too long
Sometimes I don't know what I will find,I only know its a matter of, time

Like Jerry Lee Lewis says "That’s a hit"

Ok Mr K you have done my head in again with all your bloody excitement......

So sing the following when we are all saluting to the " Bazooka"

"Help Is On Its Way"

Why are you in so much hurry
Is it really worth the worry
Look around
Then slow down

What's it like inside the bubble
Does your head ever give you trouble
It's no sin
Trade it in

Hang on, help is on its way
I'll be there as fast as I can
Hang on, a tiny voice did say
From somewhere deep inside the inner man

Are you always in confusion
Surrounded by illusion
Sort it out
You'll make out

Seem to make a good beginning
Someone else ends up winning
Don't seem fair
Don't you care

Hang on, help is on its way
I'll be there as fast as I can
Hang on, a tiny voice did say
From somewhere deep inside the inner man

Don't you forget who'll take care of you
It don't matter what you do
Form a duet, let him sing melody
You'll provide the harmony

Why are you in so much hurry
Is it really worth the worry
Look around
Then slow down

What's it like inside the bubble
Does your head ever give you trouble
It's no sin
Trade it in

Hang on, help is on its way
I'll be there as fast as I can
Hang on, a tiny voice did say
From somewhere deep inside the inner man

Hang on, help is on its way
I'll be there as fast as I can
Hang on, a tiny voice did say
From somewhere deep inside the inner man

Chuck in a skid plate for free?    I wonder if we could squeeze other Minelab dealers to do the same Dave?
Hurry,Hurry you say Vas. Was not 7 months of announcement after announcement,followed by delay after delay enough?   Oi Vas,there's only room for one "Hit" at a time on this forum.
Ahh we've listened,watched & waited long enough m8. The sooner we put it to the test,the sooner we'll be put out of our misery.
Lenoil,my apologies for straying off topic. Knowing that the new 19 inch Super D coil,will finally be hitting the shelves in a couple of weeks time,was just to much for me to hold back.  

Cheers Kon.

I just hope we are not singing "I will walk 500 miles" before we find gold with the bugger of a thing

Harb wrote:I just hope we are not singing "I will walk 500 miles" before we find gold with the bugger of a thing

To avoid this situation...park the v/h closer to the color...

Hooray the coil is coming. The price is immaterial compared to the gains from just one deeper decent sized slug. I have my extra long shaft on the zed, plastic buckle belts, trousers and pack with no metal studs or zips, extension mic for the radio that is now mounted on the back of the back pack, and now I just have to get the poly pipe on the back of my pack to get the pick somewhat out of the way. Can,t wait.
Tributer

Minelab has posted a bit more about the coil over the weekend, or I didn't spot it last week.

It appears the 19" dislikes salt much more than the 14", so this probably means that it will also saturate a lot worse than the 14" on sodden to moist ground.

* In iron mineralised ground, a GPZ 7000 detector with a GPZ 19 coil will achieve much better results than a GPX Series detector with any size Commander coil. In very salty ground the GPZ 14 coil may give better results than the GPZ 19 coil.  

http://www.minelab.com/anz/accessories-1/gpz-19-1

i would think thats the way the coil may be sent out with a spare skid plate..Kon maybe ask the dealer if they rightly do come with a spare?

cheers

alchemist wrote:I've been contemplating some of the details about this new coil to try and get a proper understanding of what to expect.
Comparing the 14 to the 19 we have approximately 88% greater surface area and 37% larger diameter.

Rough depth difference between two coils is physically a function of coil area, and can be approximated by subtracting the radius of the smaller coil from the larger.
In this case it is approximately 9.25 - 6.75 = 2.5"

Looking at Minelabs chart of target data shows some results having more than 2.5" extra range so what's going on there. It is most likely to do with the bigger coil not being affected by as much ground signal which causes the smaller coil to see the target at a lesser distance.
This effect is so marked that the Average range improvement with High Yield over the first 4 targets is 4"

So it is likely that quiet ground will not provide as much extra advantage with the 19" as hotter ground will.

I think the silence on Extra Deep is worrying.

Cheers

Above I worked out that the least we can expect between the two coils is 2.5" going by the relationship of field strength to diameter, all other factors being equal.
The strange thing I didn't fully understand was Minelabs results that showed an average 4" improvement on High Yield.
I think I know why there is this large discrepancy which cannot be all accounted for by masking ground response on the smaller coil. Obviously the Super D is a totally new beast.

The 19" centre TX coil is equivalent to a 15.5" round and the two RX coils are equivalent to two 11.5" round coils, these two together give a combined view of 13.5"
The 14" centre TX coil is equivalent to an 11" round and the two RX coils are equivalent to two 8" round coils, these two together give a combined view of 9.5"
13.5" - 9.5" = 8" we need to divide this by 2 to get the radius and we end up with 4" and empirically borne out by Minelabs Data.

I just needed to get that sorted, now the 2 week wait, this is better than Xmas, meantime I need to get busy with shoulder exercises

Sorry for waffling on, I thought it might be of interest to somebody else.
Cheers

Re (I just have to get the poly pipe on the back of my pack to get the pick somewhat out of the way. Can,t wait.
Tributer)
Would appreciate the design you come up with. Thanks

I have dug deep holes in Vic for gold, brass and rusty iron, no deep holes in WA our favorite detecting location, regardless as one of the early buyers of the 7000, I will purchase the 19" coil and see how it goes.

Peter

Golden Crack,I have never bought a Minelab,Coiltek,Detech,or Nugget finder coil,without its accompanying skid plate complete for the price of the coil.
Regardless of coil price,Minelab might not be offering a "spare" second skid plate thrown in for free,but you can bet that the new 19 inch will be coming out with its own skid plate,thrown in as part of the whole deal. Paying $1300 or $1800 for a coil & having to pay an extra $60/80 for its accommodating skid plate,would be a big mistake for Minelab.

Cheers Kon.

Hi all, I can confirm that it does come with a skid plate attached.

Thanks Slim.

Cheers Kon.

GOLDEN CRACK wrote:i would think thats the way the coil may be sent out with a spare skid plate..Kon maybe ask the dealer if they rightly do come with a spare?

cheers

Hi Ray

Are you still a Minelab dealer?

Hi Folks,
Has anyone heard if the new 19" coil will actually be in the shops and ready to go on the 14th? trying to plan the last detecting trip for the season around the release date.
Cheers, AUoptimist.

hi au. jp at clermont sent me a email, in the heading he said ETA 14TH and then lower down the -- release date 14th ---, i know some are booking travel arrangement to be in town that day, so barring unforseens, it seems, yes the buy and go date is the 14th nov. best of luck ... kev

G'Day Kev,
Many thanks for the heads-up for the 14th, that will give me about ten days to put it through its paces, I'm number one on the 19" coil list at my dealers so I will be able to pick one up on the way out to the prospecting area, lets hope there are no more hold ups.
Cheers, AUoptimist.

Looks like Ray, Karratha ML dealer has got the new 19" (test) coil, hope he can give it a good test run and let us know what he thinks about it.
http://gpwa.forumotion.com/t952-19-test-coil-arrived

cheers dave

Is this the look on the face of someone straining to hold that bloody heavy coil up with two hands, or someone who's just found a lumper?  

alchemist wrote:I've been contemplating some of the details about this new coil to try and get a proper understanding of what to expect.
Comparing the 14 to the 19 we have approximately 88% greater surface area and 37% larger diameter.

Rough depth difference between two coils is physically a function of coil area, and can be approximated by subtracting the radius of the smaller coil from the larger.
In this case it is approximately 9.25 - 6.75 = 2.5"

Looking at Minelabs chart of target data shows some results having more than 2.5" extra range so what's going on there. It is most likely to do with the bigger coil not being affected by as much ground signal which causes the smaller coil to see the target at a lesser distance.
This effect is so marked that the Average range improvement with High Yield over the first 4 targets is 4"

So it is likely that quiet ground will not provide as much extra advantage with the 19" as hotter ground will.

I think the silence on Extra Deep is worrying.

Cheers

Looking back over this thread it is now soberingly sad seeing how we were all so excited by the iminent release of this coil.

The above posts are those that I am now ashamed of and appologise for as I have made a right fool of myself.
I made a simple mistake in my calculations and took it in good faith that the results Minelab were reporting were backed by non-random empirical observations, I assumed it was a feature of ZVT, primarily the DOD coil that produced the outstanding results.

(13.5 - 9.5 does not equal 8, it equals 4 and four divided by 2 equals 2, that's 2 inches gain and not 4)

Additionally the problem of how best to quantify DOD parameters to make comparisons blinded clear focus. What do we compare it with, 12 inch round, 15" round ?

This is Minelabs chart in imperial notation with a rough grid for clarity.



To compare I originally used a chart produced by Eric Foster which is based upon a square law function of the radii and is principally for comparing mono-coil diameters whilst keeping all other variables constant.
I wanted to get a feeling for what we could expect as an average from this new coil and I arrived at around 2.5 inches gain.
However, Minelabs results with the smaller targets was showing 4.5 inches. This is where I made a simple error and proceded to announce Minelabs figures stack up and the 30% was a valid expectation, when in fact it was probable that 15% was more realistic.

Here's a copy of Eric's chart with an example applied.



On the vertical axis we have the detection depth in inches and on the horizontal, the diameter of the coil in inches. The vertical red line is the standard 14" coil and the yellow is the 19" I am using the smaller of the dimensions due to the elliptical geometry.

If we can only just detect a target at 7" (A) with the 14" coil, we follow the intersect radii around until it intersects the 19" coil line, and we get a depth of just over 6.5" so that is a reduction of ~7 percent that we can expect.

If we can only just detect a target at 11" (B) with the 14" coil, we follow the intersect radii around until it intersects the 19" coil line, and we get a depth of 12" so that is an increase of ~9 percent that we can expect.

If we can only just detect a target at 15" (C) with the 14" coil, we follow the intersect radii around until it intersects the 19" coil line, and we get a depth of 17" so that is an increase of ~14 percent that we can expect.

It would appear from this that the testing done thus far by members is in line with this and in all likelihood we can only expect the 30% increase in perculiar, or as Ion Idriess would say, 'queer' circumstances.

I am very sorry for misleading you dear members here.
Over coming weeks I hope to do some field strength measurements and comparisons so that I can nail down just what this DOD coil may be hiding if anything.

Kev.

P.S. it is most probable that the missing 15% is gained when situations allow one to run in Normal on the 19" for instance when previously only Difficult could be used on the 14"

slimpickens wrote:Is this the look on the face of someone straining to hold that bloody heavy coil up with two hands, or someone who's just found a lumper?  

No it looks like the face on someone who has just just sold you something with a 1000% mark up

LOL akubra ,
the coil looks the goods , something from back to the future ,
i think it needs the hover board thing from the show fitted to help with the weight
cheers red

Okay so looking at that chart you could say that the 19 inch in HM-HY/D has an average increase in detection depth of around 28.8% over the 14.

However that is not a true average for all size nuggets when for some nuggets the increase is only around 19% and others it is ranging between 43.4 and 38%.
     It is not possible to say that the 19 inch calculated 30% increase applies to all nuggets.

hi adrian ss , seems the chart was made up by the testers ,lol

Alchemist, is that Eric Foster chart made with a mono coil in mind?

Because ignoring ZVT/other unknown proprietary implimentation altogether and just looking at coil geometry alone, the super D will not scale with a mono coil - not just dimension-wise on each winding but also because there is no axial symmetry on any of the 3 windings as there is on a mono coil and the two RX lobes appear to me to act kinda like a differential receiver (I'm not sure the proper EEterm for that). The TX winding is kinda rectangle-ish (so comparing to a 19" mono is overestimating it) and RX are D's and offset to the side and they are also much smaller than 19".

Also, the RX winding distance proportion in the center relative to the size of the 3 windings appears to be larger than on the 14" too. So it's pretty complicated to make generalizations like we can with monos, I'm not sure its even possible. From a purely geometric standpoint you could do it with FEA software, but unless someone puts the TX output on a scope and also figures out how the RX side is implemented in the software, it's pretty much impossible from what I can gather to make any kind of scaling chart like we can with monos.

I think with a little imagination you might find an allegory to one potential software implementation of the multiple lobes on a coil like the super D. Not saying that's how it works, but just that looking at the super D like a mono (or even a DD) is probably not correct because there are a lot of things that could be happening inside the black box. Think less EE and more astronomy, I don't want to be anymore specific because I want to build it myself sometime.  

It seems like if there is a problem with the coil, it's something that might be possible to address in software later. Not to sound too conspiratorial, but I almost wonder if the plan was to sell this coil, then release a pay-to-play software update in another year that makes the same coil "more powerful". Because we know the 19" was working almost 2 years ago from JP's post. How can it possibly work worse with this much more development time? What was all that development for?

may be it needs a fractal rx
cheers red

Fractal rx they have sorted.
It's factual rx they got issues with.