Coiltek Coils For The GPX 6000 - Confirmed!

[jasong]

I detect with my phone off usually so sometimes I'm unsure if there is cell coverage or not. But the reason I mentioned cell towers is because literally the only thing anywhere even remotely close to some of these areas are cell towers. When they are in range, they are probably the old Union Wireless (or whatever company predated them) towers that were built out before Verizon, ATT and the larger carriers decided to build their own in rural areas. So they might be using some kind of strange outdated transmitter from the early cell days that the normal cell towers don't use for intra-tower communication? No idea, but that's my only thought at this point.

I have a NanoVNA, not a TinySA, but I think they are the same thing basically. But at this point I just don't care enough anymore, I just want a detector that works. I'm going to take a hit on reselling this 6000, just wasted another $400 on a coil that didn't really help. So I'm out of patience and motivation to solve ML's problem for them, they can pay me if they want help.

I just know it varies by location, that's about all I can say other than the 6000 itself has some problem dealing with certain types of EMI and of those two things I'm certain. It's hard to see until you travel enough to see the problem repeat.

[jasong]

9 minutes ago, phrunt said:

I think people would be extremely surprised to see how close to civilization I look for gold here so EMI is always an issue...

I did quite a lot of detecting this winter with the 6000 in Arizona fairly close to civilization, it was noisy sometimes, but I could deal with it. Some places it ran smoothly, no issues, in places I could hike and get a fast food burger if I wanted, that's how close I was.

Oddly, the big problems I'm having are when I came up north to areas that really have no civilization around them. 

[GotAU?]

3 hours ago, jasong said:

I did quite a lot of detecting this winter with the 6000 in Arizona fairly close to civilization, it was noisy sometimes, but I could deal with it. Some places it ran smoothly, no issues, in places I could hike and get a fast food burger if I wanted, that's how close I was.

Oddly, the big problems I'm having are when I came up north to areas that really have no civilization around them. 

It would be interesting and bizarre  if your more northern latitude was causing the issue due to the recent geomagnetic storms the Sun is causing this weekend.  There have been some great Aurora Borealis lights further south as a result, and we are going to have another CME (coronal mass ejection) hit the Earth on Sunday as well…

https://www.spaceweather.com/

[jasong]

8 hours ago, GotAU? said:

It would be interesting and bizarre  if your more northern latitude was causing the issue due to the recent geomagnetic storms the Sun is causing this weekend.  There have been some great Aurora Borealis lights further south as a result, and we are going to have another CME (coronal mass ejection) hit the Earth on Sunday as well…

https://www.spaceweather.com/

It's something I considered a few times. We had to check solar activity when I worked in the oilfield as our MWD tools would be affected when solar storms got intense, causing potential downhole steering errors.

But I don't think that's what is happening here. I can't say for certain but I think it's just some specific human created EMI frequency in combination with a design and/or manufacturing flaw on the 6000. It's just impossible to say without any input from Minelab though, only guessing, since it's not really possible to differentiate between a problem inside the machine and one outside the machine when the machine itself is a total black box. All that can be said is a problem exists somewhere. There is also the potential that I got a bad stock coil, plus a bad Coiltek coil. Or that a bad batch of 6000's was sent and everyone I detected around all had bad 6000's too such that my comparisons never included a functional machine. Lots of low probability events could make a diagnosis impossible, which is frustrating.

[GotAU?]

2 hours ago, jasong said:

It's something I considered a few times. We had to check solar activity when I worked in the oilfield as our MWD tools would be affected when solar storms got intense, causing potential downhole steering errors.

But I don't think that's what is happening here. I can't say for certain but I think it's just some specific human created EMI frequency in combination with a design and/or manufacturing flaw on the 6000. It's just impossible to say without any input from Minelab though, only guessing, since it's not really possible to differentiate between a problem inside the machine and one outside the machine when the machine itself is a total black box. All that can be said is a problem exists somewhere. There is also the potential that I got a bad stock coil, plus a bad Coiltek coil. Or that a bad batch of 6000's was sent and everyone I detected around all had bad 6000's too such that my comparisons never included a functional machine. Lots of low probability events could make a diagnosis impossible, which is frustrating.

You’re probably right about external interference, remember Simon’s photo of the way the interior of the 6K cases are hand painted with a shielding coating?

Interesting about the Sun’s effect on drilling!

[jasong]

I haven't seen the photo, but I can tell the 6000 and 7000 both aren't well shielded for no other reason than electronic devices easily interfere when brought close to the control box. 

Some types of carbon fiber is conductive, it should act as shielding, I wonder why they don't build control boxes out of carbon fiber?

[phrunt]

See the shielding paint inside, I assume they connect it to a floating ground.

[GotAU?]

51 minutes ago, phrunt said:

See the shielding paint inside, I assume they connect it to a floating ground.

Thanks for posting it.  Guess we should wrap the whole thing in aluminum foil. In addition to ice cream cover coil protective tape and shaft spin locking o-rings, there’s another receipt to submit to ML for reimbursement! ?

[jasong]

I tried a no cell reception place today and it was fairly quiet on the 6000, definitely leaning toward the EMI being a tower issue, maybe some equipment specifically used in remote locations, or older outdated equipment, or higher power maybe for longer range in sparsely populated areas? 

The control box shielding definitely sucks - out of curiosity I put my phone switched off next to the box and it interfered even when off. Yes, an off phone interferes with the box...not even the coil...that ain't good. Worse on the left side than the right. S22 phone if anyone wants to repeat the experiment and see just how poorly shielded the control box is. Sorry but IMO this detector is built like a toy in some respects, like what I'd expect out of a kids walkie talkie. I'm not saying that to dog it, I'm saying that as an observation, this is what I'd expect out of an Ace250 level machine. 

The EMI is worse on the ground. Which makes me think there is some grounded antenna  or coupling effect to the control box going on. I dunno, I'm not a ham, antennas aren't in my wheelhouse. But something is happening on the ground to make it worse.