XP GOLD MAXX POWER (GMP) - Field Test

I have commenced testing Keith Southerns XP Gold Maxx Power (18-Khz) unit. Bench test complete. Test-garden testing complete. (((Will graduate to real-world soon))). Nutshell/bullets:

1. Confirmed 'micro-jewelry' capable. (Almost as good/sensitive as 71-Khz Gold Bug-2).
2. Identical depth performance on buried clad dime as a CZ/E-Trac (in Florida inert dirt).
3. Adjustable tone-break feature for entire iron spectrum is a major attribute.
4. Having 'volume control' with the audio reports of iron is a respected attribute.
5. Very easy to understand/operate.
6. XP GMP 'reactivity' is equiv to XP DEUS setting of '2'. (On a scale of 5).
7. In 3-tone...... the delineation between mid-tone to high-tone is ironically/uncanny/coincidenetially almost exactly CZ-3D 'old-coins' break-point.
8 Swinging 8 batteries is excessive......... although unit is fairly well balanced......... medium weight.


This unit can be used as a 'old coins' hunter........... as long as you dig only the high tone.......... just like the CZ-3D. Keep in mind...... it is designed for relic hunting where people existed/habitated.............. (ie..... in/with carpets of nails). I have no idea (yet) how it handles steel bottle caps.
For those of whom watched the test-garden portion of my DVD........... the ferrous 'complex' target scenario. The GMP had a difficult time acquiring the deeper (6") clad dime amongst the shallow nails; yet, would detect the non-ferrous coin. The performance (vs my expectations) were quite good. For the record............... the F75SE in 'boost process' mode ,,,,, with the 5" DD coil.......... will detect the clad dime 100% of the time...... from any approach-direction/angle-of-attack...... with nearly any coil sweep speed....... and with a variety/host of other variables induced..... the F75 will never fail this complex-target(s).............. and has additional head-space to spare........ in this scenario. When 'boost process' is deselected...... converting the F75SE into a standard F75....... there is some difficulty detecting this complex-target scenario. This prompts a mandatory explanation/requirement. Seems like I'm demoting the GMP. On the contrary. The difference:

F75SE 5" coil. GMP 9" coil. It may sound like a minute' difference/differential between/comparing a 5" coil to a 9" coil. There is a tremendous field-intensity/footprint/electromagnetic-envelope differential (several hundred percent) between a huge 9" coil ... vs ... 5" coil. Yes........ both coils are DD..... and both coils are round (not elliptical). Whilst sweeping the 9" GMP coil......... it is always over two (or more) targets (simultaneously)............. always............. and at least one of the targets is a shallow ferrous implement(s). WHEREBY...... the 5" F75SE coil is NEVER over more-than-one target at a time. HUGE difference; and hence, my surprise to the 'partial' success of the GMP on this complex target scenario. I do not own a GMP........ and do not own a smaller/elliptical DD coil (if one exists); hence, I speculate/surmise it would have a (unknown magnitude) performance gain with a elliptical DD coil.... in this scenario.

I also want to state for-the-record (thus far)...... there are things this French unit will do...... that the F75SE will not do (performance-wise). Yet, I would be remiss if I did not also state for-the-record......... there are things the F75SE will do..... that the XP GMP will not do. Only real-world testing (in scientific 'controlled environment' fashion) will dictate/quantify unit justification. Without concrete data....... I will not share unvalidated claims/beliefs.

I am a bit perplexed as to 'why' this unit is factory equipped with a round DD coil............ when it's exacting design intent is for mineralized dirt and iron rubbish-laiden environments. A elliptical DD coil design would help in both causes.

More to share....................... out of time........................ AND..................... need to perform a real-world hunt with this unit.



Edited 1 time(s). Last edit at 04/23/2012 02:00PM by NASA-Tom.

Interesting, Tom, Thanks. HH jim tn

Why did you test the F75 5" coil instead of the normal F75 coil?

It's AS sensitive as the Gold Bug II???
Um....WOW!
Never thought I'd here that....

ALMOST as sensitive as Gold Bug-2 on micro-jewelry.

Detectorist......... 5" coil .. vs .. 9" coil. Because it is the only coil I have for the GMP...... and I do not think there is a 5" DD coil for the GMP........ and I need to know if I can hunt behind myself (F75SE w/5" coil) with this XP GMP just the way it is. Valid question, Detectorist.

(((Yes, I will test 11" x 7" DD F75SE coil against 9" round DD coil on GMP......................yet...................... still............... this is apples-to-oranges))).

That's still very impressive especially for micro jewelry

Good info Tom!

I find it the most sensitive machine I have ever used to small target's..I have never ran a Gold Bug II so That must be why LOL!

There is a 5x10 DD Eliptical available...I hear it also transforms it into the reactivity setting comparable to a 3 or so on the DEUS...

Did you find the audio talkative...Nuanced...Blending...

The depth in your dirt seems great...Well the depth in my dirt is right there with the best from my finding's so far.

Good review...How is it on your gold coin?

The machine has one main purpose and I think it show's.

Keith

"Micro-jewelry capable" and "almost as sensitive as the Gold Bug II" is what I find amazing because I NEVER had any machine EVER come close to the 71Khz GBII.

It is so powerful Keith, you cannot see most of the targets you detect with it, until they are sifted, and you cannot run the coil over your hand or it will pick up your hand! (hence the plastic sifter you need to use with it).

Thats quite a BEAST you have there, looking forward to seeing what you find w it!

FIELD PERFORMANCE OF XP GMP

This unit is a stunning real-world performer........ especially in its designed environment....... carpets of nails (old relic sites). I would have to categorize it as a parallel performer to the worlds flagship relic detector. The XP GMP has many similarities audibly to the old Fisher 1266-X. I did run the unit at its extreme ranges......... and do feel the unit needs to be in professional/seasoned relic-hunting hands.............. but can also be run at lessor performance levels for general relic hunting applications. There are real-world non-ferrous targets that the GMP would detect (amongst nails).... that the F75/T2 would not detect. It has taken several days to determine the exact cause of such phenomenon.

The GMP is not size or conductivity dependent. The spectrum of targets recovered were BB-sized through silver dollar sized. . . . and ranged from low (foil) conductivity through high (silver) conductivity.

Depth performance in real dirt (Florida soil) seems to parallel the F75....... with one issue. Coin-sized targets in the depth range of 9" - 12" are a excessively modulated audio. . . . . . a very faint/weak report. On the F75 (with higher Sens settings)........ a 2" deep dime and a 11" deep dime sound the same (amplitude).......... with a very loud audio report. With the GMP........ targets in the 2" range to about the 8 - 9" range are fairly audibly loud. Once the target is deeper than approx 9"......... the audio response ramps down dramatically. The F75 gives the illusion of 'greater depth'............ although........ in a test-garden (controlled environment)........ this is not the case......... as both units will detect a dime at 12". The audio of the GMP is quite a bit reduced/weaker......... but intelligible. In the real world......... in real environments......... these weak sounds are more difficult to distinguish.

The Sensitivity control was adjusted at 100% in most applications. Never once did I find a scenario to run the Sens above 100% (into the 'red' arc zone)...... as internal EMI issues ensue. Sometimes ground feedback (whilst sweeping coil) can 'over-ride' internal EMI component cross-talk issues......... and the Sens could be adjusted above 100%; yet, I never found this to be the case. The Sens control is a very linear (per expectations) adjustment throughout the spectrum of its adjustable range. Once again.......... this unit performs better with a higher Sens level...... even whilst sweeping carpets of nails. Audible resolution is enhanced/intelligible with higher Sens settings.

The Discrimination span is also quite linear. There is a lot of critical iron Disc performance in the Disc range of 5.5 - 10. Some areas I hunted......... I could adjust the Disc to a setting of 5.5 ........ due to the heavy decomposition status of the iron at one specific site. The square nails were of 1855 vintage. Interestingly, on the far West end of this same 1855 site....... and overlaping.... is a 1905 site. The decomposition status of the 1905 site dictated that iron Disc must be adjusted to 9.5. The "less decomposed" 1905 iron nails were the overriding factor as to where the discrimination needed to be adjusted. This hampered real-world end-resultant performance; yet, not a fault of the detector; rather, environmental conditions.

In carpets of nails......... it was of great benefit (less human fatigue) to run the detector in 2-tones (vs 3-tones). And.............. to adjust the iron 'volume' down to 1/3 volume. This is to say......... the mid-tone is at normal (full) volume..... whilst the iron low-tone was adjusted to 1/3 volume. It should also be mentioned that a substantial reduction in audio fatigue can be ascertained by adjusting the iron volume to '0' zero; however, this sets up a condition of NOT knowing exactly what is happening under the coil.... at all times. The resultant can be ghost signals.

This has to be one of the most noisy detectors I have ever used in carpets of nails............. (with 'some' of the noise being mitigated)........... yet, at flagship performance levels. One particular non-ferrous target (a copper washer) that I tested before recovering.......... presented shocking (yet expected) results. The target was detected with a Disc setting of '6'. When Disc was adjusted to '8'........ the non-ferrous signature of the target completely disappeared......... with the audio dropping to a constant low-tone. Keep in mind........ the iron Disc span range is from 0 - 25......... and with a analog dial. Also................ adjusting the Sens from 100% down to 60%.......... and the target disappeared. This also was one of the targets that I (head-to-head) tested with the F75 SE................ with both the 11" elliptical DD coil......... and the 5" DD coil. Under no circumstance.... could the F75SE detect this target. It took 90-minutes of careful recovery to determine the 'conditions' of this specific target(s). This also lead to the answer as to why the F75 could not detect this target. The copper washer was 7" deep. Off to the sides of the target were excessive amounts of ferrous implements/nails. The F75 longer/bigger 11" DD coil would 'reach' into the additional masking culprets a bit TOO much........ and mask the non-ferrous target. Installing the 5" DD coil............ and it would see/amplify too many of the shallow rust flecks/flakes above the copper washer; subsequently giving the same end-resultant............. excessively masked non-ferrous target.

With days of collected data........ several non-ferrous targets were found/recovered with the XP GMP..... behind the F75SE (with both coils). This prompted me to find a virgin site to hunt. . . . . . . but............... this time I would hunt with the GMP first. Then.............. I would go behind the GMP with the F75SE. The order of units used....is absolutely critical. Speculation (theorem-to-proof) onset...... was achieved. There were plenty of targets that the F75SE could detect........ that the GMP could never detect.

Let's start with this: The GMP has a 9" concentric DD coil....... with a specific physics-dictated 'footprint'. The F75 has a 11" x 7" elliptical DD coil with a 'different' footprint. Let's say the footprint differential is.......... say........... 21% electromagnetic footprint field-of-view difference. This means the view/window of the real-world is 21% different. Now........... add the fact that one unit is 18-Khz and the other unit is 13-Khz. This also changes the way each detector 'views' the world. BOTTOM LINE = Awash! Both detectors performed with the same end-resultant.......... that being.......... both units walked away with the same amount of non-ferrous targets being recovered...... in the carpets of nails. BUT........... these targets are NOT QUITE the same targets. Nearly 80% of the targets could be detected by both detectors. Nearly 20% of the targets capable of being detected..... are/were detector specific!

This is the first time I have seen/witnessed a detector nearly 'parallel' the end-resultant performance of the F75SE. I do feel the F75SE with the 5" DD coil in 'boost process' still takes the overall lead............ yet............ I need to collect more data. All of this testing certainly has brought about a much better appreciation of the 'boost process' engineering/invention of the F75SE.............. as I can see/feel the GMP is not a 'boost process' unit; yet, extremely capable.

The GMP is moderately heavy; yet, due to the electronics being under the armcup.......... the unit is perceived as 'light'.

I have been heavily testing (in parallel) a XP DEUS............. and have another long report to share/impart/post.

Tom

Great report! I await a 'preliminary' report on the Deus with much anticipation...

Dang!!! ,,,,,,This is great!!!
Thanks Tom!

Great stuff Tom!! Man, this is some thorough stuff!!

Hey Tom!!!

Now you know why I wanted you to test the GMP...I thought of you and your iron masking test's when I saw what it was capable of with such a large coil...

Its 100% visible to see what the engineer wanted and achieved with this machine...

Sort of like a modern day shadow X-5 with the way it hit's all conductor's well with the added bonus of the tone's and tone split...

Also the GMP came out I think it was 2 months before the T-2 so no copying went on by the XP designer's...

I myself am quite impressed with the companys attitude and direction.

Keith

Wow. Had no idea the GMP is more than 6 years old (older than T2).

Yes Tom..I found a Field test in a U.K. Magazine and it is April 2006 [www.treasurehunting.co.uk]

So has to be at least 6 years old this month...

It replaced an earlier version 18khz of almost the same design created around 2003 or so...

Thanks again for your testing...

Keith

Thanks Tom, I'm really enjoying these reports.

You are welcome............. and I may perform a bit more testing. I'm busy for the next 48-hours........ but maybe this coming weekend.

After another extensive batch of testing/detecting with the GMP......... I continue to be impressed. The GMP does seem to have slightly more 'punch' vs the DEUS. And today............. for the first time............ I was able to run the Sens deep into the red arc. . . . . . in fact, half-way into the red...... with minimal falsing/overload. I was under electrically 'lit' power lines........ and no EMI. This extra Sens boost (into the red arc) did improve performance a slight amount. Whilst relic hunting........... seeking to find/dig/recover ALL non-ferrous targets in carpets of nails............ I continue to be impressed with this units performance/capabilities. Once again........ it has proven to 'parallel' the performance of the current flagship relic hunter............. presenting equal confidence with this unit..... as with the F75 SE. Relic hunting......... once again......... dictates two-tone selection, higher Sens settings, 1/3 volume on iron (or less...... with some stipulations)............ and the minimum amount of iron Disc that iron target decomposition status dictates.

Also.......... the latter part of the day (for a few hours)............... exclusive 'old-coin hunting' in trashy areas.... resulted in exceptionally good performance....... but only in 3-tone selection..................... digging/recovering only the high-tones. Noteworthy is the fact that the 'blending' of the mid-tone with the high-tone on targets that are conductively 'right-at' or 'between' the two tones....... a tremendous amount of audible data is presented.

I will be returning this unit to Keith this week............. and certainly would learn a lot more about this unit (for additional reports/posts on this forum)....... if I were to extensively use it for several months. My interest is piqued for testing the smaller elliptical DD coil on the GMP platform...... as I feel there is knowledge to be gained (and pubically shared). And my interest is also piqued for testing the 4.6 Khz version of the GMP.

Very impressive/worthwhile unit.

Tom

Thanks for the exhaustive testing Tom....

Yes the GMP seems to have more "PUNCH" over the DEUS.....

Yes The tone's are more conveying Vs the DEUS...

It is a well engineered detector for sure when used for intended purpose...

I may locate a 5x10 DD sometime this year?...if so I will send it back down...

I have also been interested in the Gmaxx 4Khz machine...If it behaves like the GMP but on the 4 Khz platform it could really be the 1-2 punch combo...

What I am hoping for is that since the DEUS is being introduced to the U.S. market that the other machine's will show up...all that hold's them off is the wireless headphone freq and that could be easily changed to become compliant..

then the accesory coils and such would be easier to obtain.

The GMP is a quite costly detector though...right at 1000.00 U.S. dollars I believe? Maybe more..

Some more info I ran across is the designer was actually working on the DEUS 8 years ago....and the GMP was how should I say a product of his vision..Like the wireless transmitter and such...I dont think it was a by-product but it was a replacmenet for there earlier goldmaxx 18KHZ machine with some features he was working on for the DEUS...

cant look at the Xp detectors as anything but cutting edge design at this point....he was doing thing's 8 years ago !

Thanks Tom!

Keith



Edited 1 time(s). Last edit at 04/15/2012 02:42AM by Keith Southern.

"Let's start with this: The GMP has a 9" concentric DD coil..".

Tom, What is a concentric DD coil?

Hobo Wrote:
-------------------------------------------------------
> "Let's start with this: The GMP has a 9"
> concentric DD coil..".
>
> Tom, What is a concentric DD coil?

I do remember reading somewhere that they went with the concentric DD coil as it gets more depth over the oval/ellipse DD coil. Seems the Deus doesn't need more separation that the oval/ellipse DD would bring as they went with a smaller 9" stock coil??? Looking foward to the reply.

Great thread, would love to heave more about the GMaxx II at 4Khz. Seems like this could be a great coin machine in iron and trash (though there is no VID/Screen).

Yes........... "concentric DD" is a 'round' coil........... in Double D configuration

VS

A "elliptical DD"............ which the coil is elliptical................ in Double D configuration.


Albert..................... you bring up an interesting point. No meter or VDI on the XP GMP. I would NEVER want a meter/VDI on this unit. It would certainly be more of a detriment/hindrance "no dig" inducing resultant/scenario. The GMP is specifically designed to combat iron infested (carpets of nails) areas........ in 'specifically' relic-hunting applications. It is more the 'norm' (vs the 'exception')..... to have multiple pieces of iron under the coil in concert with a non-ferrous 'relic' target ....... in need of being unmasked.................. and ...................... in this scenario............... a VDI would surely induce/promote a "no-dig" resultant. More folks would 'talk their way out of' a 'dig' decision. And............ since we detect exclusively by our ears (more than most folks can imagine)........... a unit without a meter 'educates' the detectorist in many aspects........... especially if the unit is a 18-Khz base-platform.

Now............. a 4-Khz platform with a meter. Hmmmmmmmm. Maybe; yet, folks would still talk their way out of a 'dig' decision.

To Tom D, I have had the Goldie since it came out, have never understood the ground reject or settings, just run it at 12oclock. Could you explain.

I like to think of the GMP ground reject as a ground signal discriminator, not a ground balance.

If the ground gives you much noise and is free of targets increase ground reject as a discrimination like you would if it was unwanted targets.

It is a form of Grnd Balance. Try to keep it at 9am or 10am position.......... if your ground conditions permit. What you are seeking with this control is ...... harmony between unit and ground.

The XP GMP is far underrated.

I would like for EVERY single Explorer/E-Trac owner to "experience" the GMP.

NASA-Tom --

I was wondering if you could give just a bit more detail on this statement you made, which I find intriguing:

Quote

I would like for EVERY single Explorer/E-Trac owner to "experience" the GMP.

From the perspective that most guys who run Explorers/E-Tracs are specifically deep coin hunters, and since in an earlier post, you said:

Quote

The GMP is specifically designed to combat iron infested (carpets of nails) areas........ in 'specifically' relic-hunting applications.

...I'm just trying to figure exactly what you mean. I would think that if someone is primarily a relic hunter, who hunts in "carpet of nails" scenarios looking to dig any non-ferrous target, they would NOT, in most cases, have chosen their "weapon of choice" as being an FBS unit. I could easily see the GMP doing a much better job, as you have clearly pointed out.

Similarly, for those HAVE chosen FBS units, BECAUSE thier hunting style is to hunt deep silver/old coins in parks filled with modern trash (which is the application I'd say most FBS hunters use their machines for), I'd think a non-metered "relic" machine would NOT compete as well, in this specific application. So, I'd think many would likely NOT be highly impressed with such a unit. But, you obviously have some thoughts in mind -- which is why you made the original statement...and I'd be interested to better understand why you are thinking...

Thanks,

Steve

Steve,

One of the ill-conceived attributes of the Minelab units is........... most folks think they are extremely good in the iron at unmasking (((especially coins))). The GMP would be a eye-opener.
Another ill-conceived attribute of the Minelab's is.......... they have above-average adjacent target separation abilities. Again....... the GMP would be a eye-opener.
The GMP is a meterless unit. Again......... another eye-opener.

Just to name a few.

Education can be painful......... yet.......... priceless.

My old motto: - ((( I would rather hurt you with honesty...... than mislead you with a lie ))).

I grew up reading that all the good targets must be deep. This is not the case. These XP detectors are opening eyes.

MANY are 'masked'
MANY are too 'deep'

We are just BEGINNING to tackle the 'masked' scenario.

NASA-Tom --

Makes sense. I personally do NOT think FBS units are "extremely good in iron," nor "above average" at separating adjacent targets...so, that makes sense why I didn't follow what you meant. I now understand your point, and intended audience...

Thanks!

Steve