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GPX 17 Coil Commentary


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The detecting environment has some effect on the choice of coil cable routing and placement.

It was like sliced bread was reinvented when the GPZ 7000 came out with the taut tight-fitting stretched cable inside the detector shaft. Gone were the days of messing with rewrapping loose floppy cables with Velcro with each coil change.

Experience with the GPX 6000 in bushy areas has re-induced an external cable problem. Leaving a loose loop above the coil causes frequent false target sounds when swinging into or pushing under bushes.

Normally setting and raising the detector is a small percentage of the time spent in detecting. Sounds generated during those motions can be accepted.

Have a good day,
Chet
 

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3 hours ago, Chet said:

The detecting environment has some effect on the choice of coil cable routing and placement.

It was like sliced bread was reinvented when the GPZ 7000 came out with the taut tight-fitting stretched cable inside the detector shaft. Gone were the days of messing with rewrapping loose floppy cables with Velcro with each coil change.

Experience with the GPX 6000 in bushy areas has re-induced an external cable problem. Leaving a loose loop above the coil causes frequent false target sounds when swinging into or pushing under bushes.

Normally setting and raising the detector is a small percentage of the time spent in detecting. Sounds generated during those motions can be accepted.

Have a good day,
Chet
 

All very good points Chet, Chris Gholson used to firmly tape his first coil wrap in as close as possible (just enough loop to allow the coil to flex without the loop being too big) then he would run the coil lead straight along the lower shaft then have lots of coil lead wraps further up. This worked well with the GP and GPX machines but is less than ideal due to the thickness of the cables used on the 6000, plus if makes it a hassle to shorten the stems for transporting etc. This is even more evident in the colder months as the cables stiffen up considerably. As the weather warms up it it’s important to NOT have the lead too tight going up the shaft to prevent stiction as the leads are more prone to noise when they are soft and pliable compared to cold and rigid.

The point to my post was to show how sensitive the 6000 is and enlighten people to the noise they will hear when they fold the coil flat against the shaft. Obviously if the country you work is brushy and the lead snags a lot and not wide open spaces like I have the pleasure of working then modify the way you wrap the lead to suit your detecting locations.  

JP

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6 hours ago, Jonathan Porter said:

 

The point to my post was to show how sensitive the 6000 is and enlighten people to the noise they will hear when they fold the coil flat against the shaft.

JP

I truly thankyou for that....!!!!!  Don't use my 6 that much (39 nuggs) and almost used to dealing with the seemingly constant EMI although aggravating.  The one thing that really pisses me off is EVERY time I set the 6 down with coil flat it goes nuts even though I have enough loop in cable to comfortably lay coil flat.  NEVER even thought about cable to close to coil as it hasn't been a problem on my other machines but I can see where the sensitive 6 could be effected by this.  I'll make for a bigger loop and see how that helps a very annoying issue.  Thanks much for the tip....!!!!!

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Thanks for the great information folks,

Glad I’ve finally found somewhere where there is a decent discussion about the 6000.  I’m as green as they come to gold detecting. The 6k is my first detector so I don’t know any better or worse. I received mine in the second release end of May. My occupation involves near surface geophysics so I have a reasonable understanding of antennas/frequency and ground conditions. I have been really lucky with the 6k running the 11” mono, I’ve pulled out around 13 grams in the past couple of months, 8 grams of that on a patch I came across about 40m by 40m. You would suggest I run both the 14” and the 17” over this ground also? 
 

On sensitivity, I run in normal as high as I can without the audio wobbling too much (always with headphones), however I do swap over to difficult and auto modes to check if a target is noise or not. This seems to work for me and I have dug many duffers ie nothing there that ping in normal but not in difficult. Would you say this is good practice? 
 

What is the reality on auto and auto plus? I guess I need to hot swap between settings when I’m on a target and do a lot more testing. I feel sceptical about running in auto in fear of missing targets. Minelab do say the manual settings are more sensitive?

 

Thanks again

Drew

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Hi Drew - welcome to the forum.  The best settings and coil selection for the 6000 are dependent on ground mineralisation & local EMI and whether you are targeting very small shallow targets or deep targets. Some swear by auto + & others like a quieter threshold so use the manual settings.

I would definitely go over your patch with the 14" DD coil in auto + as i have had some surprising results with this coil.

The 11" mono is a sweet light thing to use & is fun  - 13 grams is pretty good for a beginning so keep on swinging and experimenting and thinking for yourself - you will pick up useful tips on this forum but it does not beat actual experience.

Are you detecting AUS or USA?

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  • 8 months later...

Now that its been out for awhile, does anyone have any other observations on what are their preferred applications for the 17"?

How does it perform in patch hunting in areas infested with hot rocks?  Does the size render it less sensitive due to averaging of a larger surface area?  Or, is it bogged down due to a having wider footprint?

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Hey JP, has Rohan told you if the 12x7 and 15x10 Xceed coils are flat wound or not? Dual layer or stacked? Seems to be some confusion going on at the moment re the upcoming new aftermarket 6000 coils....

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22 hours ago, Aureous said:

Hey JP, has Rohan told you if the 12x7 and 16*x10 Xceed coils are flat wound or not? Dual layer or stacked? Seems to be some confusion going on at the moment re the upcoming new aftermarket 6000 coils....

The whole idea of flat wound is to increase the sensitivity on older MPS machines up to the GPX5000 with DVT, however it comes at a price and as such could be considered a not so elegant way of achieving that desire with clear disadvantages in detector behaviour especially with ground signals such as X and saturation signals. The way its been explained to me is in essence the flat wound coils force the GPX 5000 and below series to demodulate early, something the electronics where never designed to do, as such there are some undesirable outcomes that come along for the ride.

I personally would not like to be using a ‘dedicated’ flat wound on a ‘designed from the ground up’ PI like the GPX6000 as its electronics have been developed to do a far better job of early sampling and ground handling than a flat wound could ever emulate on previous machines thanks to GeoSense.

As you can imagine the 6000 has massive headroom sensitivity wise so anything smaller than the standard 11” mono is intrinsically going to have even MORE sensitivity, anyone designing a coil for the 6000 is going to have to make sure it is usable in all areas and I presume to that end will need to satisfy intense Minelab scrutiny prior to being released to the public.

Based on my experiences with the Nugget Finder 12x7 Xceed it is not a dedicated flat wound winding, it did not show the typical difficulty in pinpointing a target a flat wound demonstrates especially when moving/retrieving a tiny target across the windings but did show amazing sensitivity and ground handling ability. During my time with it target retrieval and pinpointing with the NF 12x7 Xceed where very exact and precise. 

Hope this helps
JP

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