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GPX 6000 - Emi Troubles - Some Data For Minelab?


GPX 6000 - EMI troubles - Some data for Minelab?  

17 members have voted

  1. 1. Have you experienced bad EMI whilst using your GPX6?

    • Yes - but very little and nothing I can't tune out.
      5
    • Yes - small to medium levels but I put up with it as I don't want to 'dumb down' the detector.
      5
    • Yes - frequently to almost always.
      7
    • Yes - constantly, regardless of what I do.
      0
    • No, not at all.
      0
  2. 2. If EMI has been giving you troubles on the GPX6000.

    • The EMI is worse when using the in-built speaker.
      7
    • The EMI is the same regardless of which audio option I use.
      2
    • It is better at Manual Sensitivity of 1 but I feel I am losing detecting performance by having to do this.
      9
    • At the exact same location the EMI handling is better using the 14" coil in EMI Cancel mode.
      2
    • I have turned off/left in the car all electronic devices and it made no difference.
      7
    • It is worse in Difficult mode.
      0
    • It is worse in Normal mode.
      3
    • It is worse in any of the Manual Sensitivity settings.
      1
    • It is worse in either of the Auto Sensitivity settings
      3


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Considering the frequent mention of EMI troubles with the GPX6000 I thought it might be interesting to make a topic specifically for it as it may provide some answers/options for users.  

The poll might also give us an indication of what users think may be the biggest contributing factors to EMI for their locations or GPX6's. 

With a little feedback and data maybe it is something Minelab can update for us?  

I generally don't find EMI bad on my GPX6 in the locations I use it.  

I was within a few kilometres of the centre of Bendigo (about 100,000 people) last weekend and was able to run in Auto 1 with only a little mess to the Threshold.  

At another location not far from a tower (NBN or mobile - not sure) I pretty much had to use Sensitivity 1 the whole time if I wanted to use the Mono 11" coil.  BUT, this allowed a really stable threshold and performance was still fine with gold found.  

I actually carry my phone (iPhone) with me and have it turned on.  Always in my L) pocket.  I have tried turning it off and turning it off and leaving it in the car but don't feel it made any difference at all.  

I do find the in-built speaker creates a noisier threshold and more frequent noise cancels are required. Since having the Bluetooth receiver and using my preferred out-of-ear ear buds I have found EMI much less of an issue.  

Be interested to hear others thoughts and work arounds.  

Cheers,  N.E.  

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I have very little EMI trouble with the 6K, do notice it is more amplified when using the speaker, at times it goes unstable as the sun rises and sets more so then the earlier VLFs, PIs and Z did but I have simply learnt to stop with coil on ground until it stabilizes (couple of secs usually) then re auto cancel in MDs with that capability. I carry my mobile phone in pocket turned on with no ill effect. Turning mobile phone off makes no difference, I use Auto+, difficult mostly and patch hunt in threshold off (Bogenes) clean up with threshold on and in normal. 

Solar Cycle 25 Is Here. NASA, NOAA Scientists Explain What That Means | NASA

Press release above explains the suns natural EMI increase as the sun cycle heads to max in approx 2025, also because OZ is in winter and the US is in summer effects may be more amplified in the US currently. Those of you who are inquisitive google the Maunder Minimum for a wee more understanding of the suns cycles effects on life on earth. Could be this has naught to do with detectors/EMI, but is food for thought for all our modern sensitive electronic equipment especially now as we approach a maximum sun activity period from the minimum in 2019.. 

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I've heard anecdotal evidence about more recent troubles with MIQ EMI...as if the past year or so, people are having greater problems with it.

So increase in solar radiation due to the Solar Cycle would make a lot of sense. It might even explain other issues concerning a machine's level of "chattiness."

Now, I wonder if it even played a role with the Garrett AT Max and why so many people had problems with how sensitive it was. Perhaps during Garrett's testing of the AT Max (which I imagine was a bit abbreviated given how it was based on an already existing machine and tech), there was a relative "lull" in sun spot activity. Then when it was released in 2018, sun spot activity was higher than during it's testing stage (mostly during 2017, I imagine)

Instead of a Maunder Minimum, we had a "Garrett Minimum."

EDIT: Looks like from 2017-2020, we had less solar activity as Solar Cycle 24 ended and Solar Cycle 25 began. https://www.almanac.com/content/solar-cycle-updates-and-predictions#

And there was a spike in solar activity, but it came in late 2017.

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I could not use my GPX yesterday with the speaker due to noise. To test this I sat down, and let the detector hum without any movement for about a minute. Then I switched to the supplied Bluetooth headphones.

The pitch variation was worse with the speaker. At about 101F it was too hot for headphones but I was left with no choice.

I repeated this test today earlier in the day and the speaker seemed to effect the threshold less. My guess is that the amplifier and speaker windings are inducing noise somehow. I will write Minelab about this issue since after spending six thousand dollars I would really like to use the speaker. However since today I could not replicate the issue, it may only happen during bouts of bad EMI or maybe the component just needed some time to bed into the pcb.

If the issue persists I will send it in for repair or request a solution. I am very surprised Minelab released this detector with the issue since I’ve seen others report the same thing.

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Personally the EMI "issue" hasn't been an issue for me?

I do mainly use the headphones at the moment being winter here but I'm finding the GPX6000 with GPX11 mono is markedly better with EMI than previous GPX models. Any EMI I have experienced has been easily & quickly dealt with using auto tune &/or settings. I haven't needed to resort to the GPX14 DD at all as yet even though Minelab recommend it for EMI situations. 

To put this into context the public ground in NSW that holds gold prospecting opportunity is also regularly home to public EMI producing installations i.e. LV/HV powerlines, phone towers, railway, air traffic zones, fences/electric fences etc. etc. that I deal with at least one of mostly every day (if not 2 or 3) I detect. Granted we don't have the amount of air traffic that the USA has but the 6000 to me noticeably  handles what we do have many times better than previous GPX's with mono coils. Even private property here has a lot of various man made EMI sources. None of this, private or public, includes the different natural spherics encountered also.

I find the GPX6000 up with the GPZ & SDC in these areas with the correct settings etc. 

Now I'll duck for cover 😮

Reading between the lines + from what I've personally seen with a couple of operators a lot of issues could be attributed to the operator IMO.

I've seen a tendency for operators to try to run it flat out in auto+ or manual ~10 in areas you just can't do that with the mono. Less is sometimes more!

I've also seen a tendency for those using the speaker to turn it up to high levels or even flat out. All this does is amplify everything - ground noise, EMI, target signal etc. Again less is sometimes more & targets will still be very apparent even with lower volume levels, test some targets & adjust. Some tend to think they'll miss something at a lower volume but have it so loud it just becomes a rude, confusing noise to me.

A lot are also confusing EMI with the ground balance getting thrown out. This machine is very very sensitive & large targets or inadvertently getting the pick near the coil can & will throw it out of balance. Very quick & simple to fix using the quick track button in most cases + re-auto tune if necessary. You can audibly hear it happen on a number of videos when digging holes & the pick starts to upset it. I've learnt to keep the coil well away while digging. It seems much more sensitive to this than previous GPX's etc.

The sensitivity of the 6000 seems to be taking some getting used to IMO.

I think it's great 👍

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Usually  switching to a smaller mono coil or DD coil on the older units does away with alot of the EMI Opps wait the 11 inch mono is  the smallest coil and might be for some time sorry 6000 users  :wacko: :ph34r: 

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1 hour ago, afreakofnature said:

For a detector that sounds so simple to use……..maybe it really is not so simple after all.  

It very well could end up being your particular locations emi that ends up determining whether or not the 6 is the ticket or not for you?  It's a high strung machine but maybe so sensitive in some locations it's just not worth the aggravation, frustration, and constantly fucking with it to actually ENJOY your time out in the brush...????  Time will tell.....

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6 hours ago, AussieMatt said:

Less is sometimes more!

Yep.   You've put it more succinctly than I did.  I think we aren't losing much by running in manual Sensitivity 1 or 2 when required, and are perhaps gaining a lot more in having a neat and tidy threshold.  

 

4 hours ago, afreakofnature said:

For a detector that sounds so simple to use……..maybe it really is not so simple after all.

Na, it really is simple  😀   

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7 hours ago, oneguy said:

It very well could end up being your particular locations emi that ends up determining whether or not the 6 is the ticket or not for you?  It's a high strung machine but maybe so sensitive in some locations it's just not worth the aggravation, frustration, and constantly fucking with it to actually ENJOY your time out in the brush...????  Time will tell.....

Could be, but man that is a $6000 dollar chance to take.  I guess resale value ATM though would be enough to justify.  
 

I wish I could “see/hear” the problems people are having.  From what I have “seen”, it sounds more like an SDC threshold which for me I have learned to “listen through” for repeatables.  The EMI that I have experienced with the SDC sounds more like a constant wee ooo wee ooo wee ooo or the occasional distant lightning strike.  Are the EMI troubles people are having anything like I have described?

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