GPZ 8000 Z-Set Toroidal Coils

[Chet]

Possible GPZ8000 coil configurations as per Bruce Candy patent of April 2024. Different winding layouts provide different depth, ground and EMI performance

 

[Chet]

The 17" and 18" coils are similar in size but have different windings to use for different conditions.

 

[TheDeepseeker]

Thanks for that Chet. That's interesting. I'm no wiz with this stuff so I wonder if the end result is that you have the different characteristics of different sizes/ types of coil all at once? I'd imagine it would certainly make it harder for some of the aftermarket coil makers to replicate.

It may also help the Minelab detractors (and I admit I'm often one of them) understand just how much time, money and development goes into bringing this ground-breaking technology into fruition. According to the above this idea all started rolling back in 2021. I'm sure Minelab would be paying a lot of skilled people a lot in salaries etc., long before ML sees a return on their investment.

[Gold Catcher]

It will be very interesting to compare the new Z‑set coil and its GeoZVT implementation with the conventional ZVT platform of the 7000. The key question is what the real advantages will be in the field, especially at a likely USD 15k price point. Does it incorporate a more advanced DSP—similar to the innovation that made the 2000 such a major leap forward? And what does this mean for the 7000—does it effectively become obsolete or even discontinued?

The included 18‑inch coil is great for open, low‑trash ground, but most of my detecting calls for a smaller coil, something around 12 inches like the NF. Do I really have to pay extra for that, and how much more will it cost? For somewhat shallower detecting, how does it actually outperform the 6000, or even a 7000 fitted with an X‑coil or a NF 12?

Lots of questions, and I’m sure they’ll be answered over time. But at 15k, this isn’t a casual purchase. If the real advantages only show up with the larger coil set, this detector may be better suited to the Australian market. In the U.S., there simply aren’t that many deep, large nuggets left.

GC

[Doc]

This is what intrigues me.  The technology of that unique coil design.  Yes it looks weird, but if it's doing something beneficial in terms of improving overall performance, that's what we are all looking for.

I like it when something looks different for a reason.  Not just aesthetics.

It's exciting that Minelab has innovated something that hopefully will be an improvement over the GPZ7000.  I just hope exciting doesn't mean being so expensive that there is a reluctance to invest.

I'm sure a high price tag, might be justifiable in places like Australia with gold going for $5000 an ounce, where you might find a two ounce slug.  But us Yanks don't get into that kind of gold chunks very often.  Not unheard of, but certainly not the norm.

I remember when Trevor from Coiltek came over to the U.S. and Rob Allison and I arranged with some friends of ours to take us to their private claim "lease".  Trevor had never found a 1 ouncer before.  I told the claim owners to go ahead and take him over to the gold producing area they had been working and I would go ahead and set up the tent.  I swear this is true!  I had not even got the tent unrolled and I hear Trevor hootin' and hollerin'.  He had found a 1 ounce plus nugget in the side wall of a gully.

I told him that's about right, you have to come all the way to the U.S. from Australia to score your first 1 ounce nugget.  It sure took the heat off me.  During his visit I had planned to take him to upscale restaurants, Las Vegas shows, great buffets.  I think I could have fed him peanut butter sandwiches because after that slug he found nothing could have ruined his trip to the U.S.

Doc

[Lesgold]

The initial view of the coil shape was a bit of a surprise. Realistically, it’s basically just different to anything that we have seen before. We have been accustomed and conditioned to expect something similar to what we have used or experienced in the past and this new design is way out in left field. Will it catch on vines, sticks and rocks? Some of the testers will give feedback in this regard. If you look closely at the earlier pictures you will notice that there are a number of potentially good design features that may actually help in the field. Spreading the lugs over a greater distance may in-fact reduce the wear issues that we experience on the 6000 and other older machines. The coil lead appears to be covered in the lower section which has obvious advantages when detecting in scrubby country. Finally, the under section of the coil appears to have quite significant bevels on the under surface which means that the coil would potentially rise and ride over obstructions on the ground such as small rocks and twigs regardless of the coil movement direction. 

[EL NINO77]

I'm not an electronics expert....but the toroid principle is often used in transformers in modern electronics...here it is seen that Minelab has once again thought outside the box of already used design ideas and used something new...It is hard to say how much more effective such a construction is...so practical tests and comparisons of GPZ8000 with GPZ 7000..will show us something more...

[Chet]

54 minutes ago, Alchemist said:

I've been making coils for my GPZ since the Z offerings came on the market. I came to realise the extra benefits gained by using a mix of solenoid to spiral combinations to tailor the array to small surface or chunky deep targets.

I think the 7k performance would also be greatly enhanced using this coil topology, such that the 8k margin would depend upon Geo sense and 2nd generation ZVT

By rough calculations the GPZ 7000 Double D Z19 coil has 177 square inches of transmit area and 190 square inches of receive area. The new GPZ 8000 Z18 coil has 255 square inches of transmit area; an increase of 44%.  The new Z18 coil has 255 square inches of receive area; an increase of 34%.

This increase in coil performance plus improved GPZ 8000 electronics performance could turn out to be a real winner. I look forward to some good comparison tests between the GPZ 7000 and the GPZ 8000 on deep targets.
 

[Dutchman4]

1 hour ago, Chet said:

By rough calculations the GPZ 7000 Double D Z19 coil has 177 square inches of transmit area and 190 square inches of receive area. The new GPZ 8000 Z18 coil has 255 square inches of transmit area; an increase of 44%.  The new Z18 coil has 255 square inches of receive area; an increase of 34%.

This increase in coil performance plus improved GPZ 8000 electronics performance could turn out to be a real winner. I look forward to some good comparison tests between the GPZ 7000 and the GPZ 8000 on deep targets.
 

And the 8000 will have to have significantly (1.5"+) more depth on 1 gram+ nuggets than a stock or modded 5000 using large spiral/flat wound coils.