Yes! New Coils For GPZ 7000!!!

[Norvic]

58 minutes ago, Jonathan Porter said:

How could you know one way or the other if the ‘chip’ can dumb down a coil on a GPZ, and if so why would ML even consider dumbing a coil down through the chip in the first place?

Hey JP and anyone else who considers this is what I was saying, I did not suggest the chip dumbs down the coil,  I suggested to have ML allow the  chip on the coil the coil had to be dumbed down to MLs specs, and that I understand is how manufacturing goes, the need for the coil to handle all ground types encountered by World wide users. No drama there as that will allow a coil with the chip to appeal to the wider market which is obvious from the wider markets reluctance to the patch cable. 

I trust this clarifies my thoughts and clears up any need for this subject to "get out of hand".

[flakmagnet]

I'm sure ML (and NF), knows that the first thing that will happen with a new coils' release is that it will be tested and compared to an x-coil. Maybe dumbing down is an apt term but is carries a worrisome connotation in the world of comparisons.  

[Jonathan Porter]

I think this needs clarification, firstly there is no connection between dumbing down and meeting proper electronic requirements and secondly the chip is an intentional security feature. I'm not sure if Minelab ever intended the chip to be offered to third parties but the lack of them supplying other coil options has created the demand if people are willing to go down the current risk path. More power to the brave if they are lucky enough to be working in ground that allows it.😎

If a coil does not reach correct electronic requirements how can that be considered an improvement except in specific areas? I've clearly demonstrated the issues related to this subject in videos placed on this forum.

JP

 

[Steve Herschbach]

I agree Simon. Coils need not work well everywhere. We used to have mono coils for mild ground, DD coils for tougher ground, and Salt coils for the worst ground. If people can’t understand something like “recommended for low mineral conditions only” then too bad for them. I’d like “hot” coils for places that can tolerate them.

Hopefully we get some more news on these coils someday. Nothing new since December. Do you have to rob another coil on the security chip to make one of these coils work or not? Simple question, no answer forthcoming.

[klunker]

 We used to have detectors with selectable soil timings and lots of other stuff to fiddle with that allowed you to adjust for changing soil conditions. In this area it's not uncommon to go from Serpentine to Shale to volcanic ash to washed gravel to clay to forest soil made of all the previous in different mixtures thereof all within an hours time.

 I'm much too lazy to change coils and too cheap to buy them and I had to work for a living today so I'm grumpy.

[Norvic]

I understand MLs manufacturing detectors and coils for most gold conditions, as a manufacture myself, albeit a lot wee smaller than ML, I did the same with my RV/solar fridge/freezers, rather then build them with a fan forced condenser I dumb them down to a naturally cooled condenser, not as efficient but less likely to create problems down the track ie. more user friendly. Especially to prospectors who as I`m one are a wee rough on gear.

[mn90403]

7 hours ago, phrunt said:

Out of interest, what are the soil conditions like in Africa, Russia and other areas that Minelab say are their biggest markets, bigger than Australia for sales of detectors.  Are they all heavily mineralised? I guess the Middle East would have high salt content and they're a big selling area.  This is why I think coils for different markets and soil conditions would be good.

What are the unit sales in these areas or is that proprietary data only seen in the boardroom and not in investor info?

[Jonathan Porter]

On 4/28/2020 at 10:20 AM, Steve Herschbach said:

I agree Simon. Coils need not work well everywhere. We used to have mono coils for mild ground, DD coils for tougher ground, and Salt coils for the worst ground. If people can’t understand something like “recommended for low mineral conditions only” then too bad for them. I’d like “hot” coils for places that can tolerate them.

Hopefully we get some more news on these coils someday. Nothing new since December. Do you have to rob another coil on the security chip to make one of these coils work or not? Simple question, no answer forthcoming.

I agree Steve, essentially that is what I have been doing with the coils I presently have on hand. In the case of the GPZ a more sensitive coil (for the want of a better word) would be desirable if the situation was akin to the mono versus DD scenario of the SD/GP/GPX machines. However we have to think laterally for a minute to keep things in perspective, MPS machines using Normal timings had mono and DD options, where you could use a mono coil in the vast majority of ground (I know because I did exactly that all over Australia), MPS GPX machines got the benefit of the Smooth class of timings and monoloop coils without the reduction in depth which really opened up the variable ground especially for the mid sized nuggets that had been previously lost in the ground noise.

A DD coil provides some cancelling of the Ground signal because of the two windings needing to be nulled (this is an extremely basic explanation but will suffice in this instance), there is an immediate loss in depth across the board which can be about 20%, this is for two reasons the one just mentioned and also due to the Tx and Rx windings being smaller relative to overall coil size. This is also why ML do not recommend using the Smooth class of timings with a DD, the depth reduction becomes overkill.

So to put the power of ZVT into perspective you need to reflect back on the MPS machines, firstly it has a balanced coil, the tech cannot work effectively with a DD coil so needs a DOD design, this means the coil needs to be nulled so there is a lot of ground signal reduction going on and is why the GPZ is so smooth over variable ground in spite of ZVT. Secondly the GPZ also has the Smooth Class of timings in the form of Difficult mode which was a BIG NO NO on MPS using a DD. I hope this goes some way to explaining the differences between MPS and ZVT?

So as discussed the coils currently on offer do provide some sensitivity increase but also suffer from Saturation and poor X balance but in a lot of areas thanks to the flexibility of the GPZ they are quite effective so can kind of be thought of as a monoloop like option but the range of ground types for them to be effective is quite different to MPS/mono, the bad X balance could be able to be designed out of the coil without losing the sensitivity advantages of the flat wound Tx, Saturation will always be present (goes hand in hand with the sensitivity increase) because of the nature of the windings but is maneagable. 

The other advantage is in the range of sizes available and less weight and is IMHO where they offer true advantages. A smaller coil really has a big impact on nulled coils, this was always the case with DD designs for the MPS machines, the bigger coils did not really show a lot more advantage on depth with the effect being more subtle similar to comparing the GPZ14 to the GPZ19 coil, it requires a more dedicated and refined approach. 

I sincerely hope NF offer a range of coil sizes to fill in the gaps, not having to go through the coil lead modification would be icing on the cake but a big negative for me otherwise. Something smaller than the GPZ14 would really fill in the gap and something bigger but smaller than the GPZ19 that is nice and light but not too big that the salt signal kills things in too many areas would be my dream coil. Am keeping an eye on any news from NF with extreme interest, as NF dealers we are getting emails on this subject constantly now.

JP