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GPX 17 Coil Commentary


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Ah OK, so nuthin 'official' from Rohan. But based on your in field testing you suspect its just a bundle wound coil...Interesting and a bit disconcerting. The X6 still uses MPS (dunno about DVT but I suspect it does) so the design parameters appear to be the same as the earlier GPX units anyway, just with added geo-feedback and filtering/code adjustment on the fly. The 11" mono and 14DD supplied by ML both have layered flat-wound designs so its obviously whats supposed to be used with it, at least in the smaller sizes. The larger and smaller coils will obviously need to be bundle wound due to size constraints and signal saturation as you rightly suggest. 

Given your top notch field testing results, Im still sure we will get a great coil regardless, but just curious as to why the bundle wound style was used instead of the flat wound which appears to be what the 6000 is meant to use in regards to the small-medium sizes....

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52 minutes ago, Aureous said:

Ah OK, so nuthin 'official' from Rohan. But based on your in field testing you suspect its just a bundle wound coil...Interesting and a bit disconcerting. The X6 still uses MPS (dunno about DVT but I suspect it does) so the design parameters appear to be the same as the earlier GPX units anyway, just with added geo-feedback and filtering/code adjustment on the fly. The 11" mono and 14DD supplied by ML both have layered flat-wound designs so its obviously whats supposed to be used with it, at least in the smaller sizes. The larger and smaller coils will obviously need to be bundle wound due to size constraints and signal saturation as you rightly suggest. 

Given your top notch field testing results, Im still sure we will get a great coil regardless, but just curious as to why the bundle wound style was used instead of the flat wound which appears to be what the 6000 is meant to use in regards to the small-medium sizes....

I have never heard the 6000 windings being described in that way so I presume the words you are using are your observations based on X-rays you’ve seen? No engineer I’ve worked with has described the windings in that way and I worked extremely closely with them on the 6000 right from the ground floor.

I’d say both CT and NF will need to design within the very strict parameters that Minelab set so windings will need to be extremely similar to what has been shown in X-rays if that helps. 🤔 

JP

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1 hour ago, Jonathan Porter said:

I have never heard the 6000 windings being described in that way so I presume the words you are using are your observations based on X-rays you’ve seen? No engineer I’ve worked with has described the windings in that way and I worked extremely closely with them on the 6000 right from the ground floor.

I’d say both CT and NF will need to design within the very strict parameters that Minelab set so windings will need to be extremely similar to what has been shown in X-rays if that helps. 🤔 

JP

The words are those of Eric Foster who first designed the flat (spiral) coils back in the 80's. If the coil wire is not bunched into a tight bundle and laid flat instead (either singularly or in layers), then its flat wound. Its a very common term within technician circles because various other EM coils use the same layout. Maybe the techs dont use tech terms to laypersons???....dunno.

Thanks for the input, its cool to hear your take on it, especially your in-field observations. Trevor F has muddied the water by not knowing the terms either. Im sure they will all work 100% but the theory is that flat wound is better for medium sized coils as evidenced by ML using them for the 6000.

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58 minutes ago, Aureous said:

The words are those of Eric Foster who first designed the flat (spiral) coils back in the 80's. If the coil wire is not bunched into a tight bundle and laid flat instead (either singularly or in layers), then its flat wound. Its a very common term within technician circles because various other EM coils use the same layout. Maybe the techs dont use tech terms to laypersons???....dunno.

Thanks for the input, its cool to hear your take on it, especially your in-field observations. Trevor F has muddied the water by not knowing the terms either. Im sure they will all work 100% but the theory is that flat wound is better for medium sized coils as evidenced by ML using them for the 6000.

So you've used your understanding of Eric Foster's words to describe what you've seen in the xray pictures?

Technically I'm not sure how to describe the way they're wound, that's not my area of expertise. All I know is the way the coils I've tested have behaved, what they've been like to operate in Goldfields environs and how they compare to each other, I'm more than confident you'll enjoy that similarity too.

JP

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They are very common terms nowadays, every second post about coils mentions them....usually  'spiral or flat'. Cant wait to trial the 12x7 though, its my dream size for the 6000. So glad you've had the time using it yourself and got such great results....bodes well for the future!

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  • 2 weeks later...

So I sent my 17’ coil in to have it checked and after it was connected to the coil test in a few minutes the coil became very unstable and extremely touch sensitive the coil was declared defective and a new 17” replacement coil is shipped and on its way.

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