From Euphoria To Despair

[Bryan]

Thanks for the kind words, SchoolofHardNox. I felt so bad that it was DOA. I just had a customer whose 11" coil was bad and causing the same error. Works fine with a different 11" and fine with the 14". All we want is for you all to receive a working product that you are happy with. This GPX roll-out was, shall we say, less than smooth.

Again, thank you for the kind words. I wish everyone was as understanding and patient as you were.

 

-Bryan

Alaska Mining & Diving Supply

907.277.1741

[Roughwater]

Glad you are good to go now.  I gotta say though, the 5000 ain't a bad back up.  Dated or not, it's a powerful machine!  

[schoolofhardNox]

43 minutes ago, Roughwater said:

Glad you are good to go now.  I gotta say though, the 5000 ain't a bad back up.  Dated or not, it's a powerful machine!  

The 6000 is doing better than I thought it would for tiny targets, better than the 5000. But it still has to prove it can hit a silver dime at 18" at the beach. If it can do that, I will be torn on making the 5000 my back up machine ☹️

[1911Colt]

For a ridiculous $6,000, they ought to just send you a whole new unit no questions asked, in fact I would demand it, the one you got could be a lemon giving you problems for years to come.

[mn90403]

4 hours ago, 1911Colt said:

For a ridiculous $6,000, they ought to just send you a whole new unit no questions asked, in fact I would demand it, the one you got could be a lemon giving you problems for years to come.

I think that is what happened.

[schoolofhardNox]

22 hours ago, 1911Colt said:

For a ridiculous $6,000, they ought to just send you a whole new unit no questions asked, in fact I would demand it, the one you got could be a lemon giving you problems for years to come.

I had a new machine sent to me in 4 days. That was even before I sent the broken one back. I can't ask for better service than that. 🙂

[schoolofhardNox]

So I had my third hunt with the 6000. It was a short hunt at another native site that was not inhabited for very long, and a bit newer than the village I'm used to doing. 1637 vs 1723.  So targets will not be as plentiful as the other site, even though it's the newer site. I picked this area because it has some fairly hot electrical lines running along side it, as well as the Acela train fairly close by. Both of those gave my GPX 5000 problems when I got near them. I started by using the 11" mono coil, since it performed better at the previous location. It did not handle the EMI well at all, even on 1 bar sensitivity. So I reluctantly switched to the 14" DD to see if the EMI cancelling would be better here than at the previous spot. Since the EMI was way more noticeable here, I did not expect much. To my surprise, it handled the EMI extremely well. purred like a kitten 😄. I'm not sure why that happened but it did. I also noticed that running ground difficult at this site was detrimental to getting a clean signal but normal picked the target up clearly!  Again, opposite from the previous site. Even though the sites appear similar in soil and vegetation, and were relatively close to each other (about a mile apart), they responded completely different. The only similarity between the two sites was that I found quite a lot of small targets that the 5000 missed. These were shallow targets in the 1/2" to 7" range mostly small lead shot, 22's and their casings, and some thin scrap brass. A couple of nice rose head nails sounded loud and clear as well. The 6000 is showing me that I should have experimented more with other timings on the 5000 to try and get these small targets to respond. All and all I'm still more impressed with the 6000 than I thought I would be. Next week, if all goes well, I'll be at a Rev war site project to see what I can find for their project. I hear this guy detecting there is a very good detectorist, so I'll be bringing the 5000, 6000 and EQ800. I love a challenge 😉

[Chase Goldman]

8 minutes ago, schoolofhardNox said:

So I reluctantly switched to the 14" DD to see if the EMI cancelling would be better here that the previous spot. Since the EMI was way more noticeable here, I did not expect much. To my surprise, it handled the EMI extremely well. purred like a kitten 😄. I'm not sure why that happened but it did. I also noticed that running ground difficult at this site was detrimental to getting a clean signal but normal picked the target up clearly! 

The the two coils in the DD enable common mode noise to be cancelled out by running the current in opposite directions in each loop in EMI cancel mode (not sure if you were running it in EMI cancel (default) or conductive ground cance which requires a long press of the noise cancel button). The trade off (usually) is that you get less depth than a 14" mono (or possibly even the 11" mono depending on how ML electronically switches each of the DD coil sections - not familiar with ML's approach as far as the GPX 6000 is concerned).  But at a site like the one you were at, the trade off is well worth it when the alternative is throwing in the towel with the mono.

[schoolofhardNox]

13 hours ago, Chase Goldman said:

The the two coils in the DD enable common mode noise to be cancelled out by running the current in opposite directions in each loop in EMI cancel mode (not sure if you were running it in EMI cancel (default) or conductive ground cance which requires a long press of the noise cancel button). The trade off (usually) is that you get less depth than a 14" mono (or possibly even the 11" mono depending on how ML electronically switches each of the DD coil sections - not familiar with ML's approach as far as the GPX 6000 is concerned).  But at a site like the one you were at, the trade off is well worth it when the alternative is throwing in the towel with the mono.

 Thanks Chase, So they are running opposing currents.... Hmmm that's interesting. I did try running in EMI and in ground cancel and I'm not sure which one I stuck with. I think once you shut the machine off it reverts back to EMI mode, so I can't tell anymore. I was just happy that it ran smooth. I have 2 more land hunts planned before my beach season starts. Then I'll be playing a lot more with ground / EMI modes. Back to the current thing.... so if that is how the machine works when you put the DD coil on, then those opposite direction currents run in both EMI cancel and ground mode, or just EMI cancel mode??? If they run that way for both, I should be able to run ground cancel for the salt on the beach while still getting some benefits of the EMI cancel. That would be my go to coil for some beaches for sure.

[Chase Goldman]

5 hours ago, schoolofhardNox said:

 Thanks Chase, So they are running opposing currents.... Hmmm that's interesting. I did try running in EMI and in ground cancel and I'm not sure which one I stuck with. I think once you shut the machine off it reverts back to EMI mode, so I can't tell anymore. I was just happy that it ran smooth. I have 2 more land hunts planned before my beach season starts. Then I'll be playing a lot more with ground / EMI modes. Back to the current thing.... so if that is how the machine works when you put the DD coil on, then those opposite direction currents run in both EMI cancel and ground mode, or just EMI cancel mode??? If they run that way for both, I should be able to run ground cancel for the salt on the beach while still getting some benefits of the EMI cancel. That would be my go to coil for some beaches for sure.

You are asking some great questions that I can't really answer because I have not done a deep dive into the available technical information on the GPX 6000 (other than reading the 6000 user manual) wrt to how it implements EMI mitigation- which knowing ML - I am sure is sparse and/or amibiguous - lol.   I want to caveat the statement in my previous post regarding the opposite currents cancelling noise in the two D coils - that is one way to take advantage of symmetric dual coils but I do not know if that is the specific ML implementation.  All I can say based on the user manual information is that it compares signals in the two coils in both EMI and Ground Cancel mode and utilizes the signal comparison to implement the cancellation of common EMI or ground noise signals.

Anyway, from what I can tell, ML is also utilizing some sort of EMI mitigation algorithms for mono coils too and I assume they can apply that algorithm to the DD regardless of whether it is in EMI noise or ground noise (conductive/salt ground) cancel (that is implied by the noise cancellation guidance on pages 13, 14 and 19-21 of the user manual).  So I definitely thought of you regarding what setting would work best on your EMI saturated beaches that you hunt in the "cold" seasons.  I presume when on your beach sites, you will need the DD in conductive ground cancel mode for the salt and then see if you can mitigate EMI using the EMI cancel algorithm.  If EMI is still unbearable, then I would experiment to see if you could actually get the 6000 to run stable on the beach in EMI cancel mode.  It looks like you have one of those excruciating "either or" situations since you apparently can't run in EMI cancel mode and "Salt" cancel mode simultaneously.  Really looking forward to what you find out on the beach and hopefully you can find a sweet spot settings wise.  GL HTH