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Kruzer Coil Question On Depth And Weight


kac

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I just got my 11" coil in and it seemed super light. Comparing it to the stock 7x11 that weighs 471g w cover and cable the 11" coil only weighs 492g with cover and cable.

Depth wise the 11" seems almost the same or at least air test I can't really tell.

Did they reduce the amount of copper in the 11"? Tech specs say it should weight 540g.

If anyone has an 11" for their Kruzer or have an Amphibio stock 11 can they post the weight of it? Thinking my coil is out of spec.

Thanks

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  • The title was changed to Kruzer Coil Question On Depth And Weight

Do to the lack of support from Nokta in the past I was forced to return the coil back to the dealer. May cost me 20% but better than being stuck with a piece of junk. I have a suspicion the coil is miss marked. My thoughts is it might had been a Simplex stock coil with the wrong barcode and product number. If that is the case then I fear there are more than just one of these miss marked coils being distributed to customers.

Most people may not know the difference but having the bit of experience under my belt I picked up on something being wrong right away. I am very unhappy how Nokta has been with their customers. As much as I love my Gold Racer and the Multi Kruzer, if I had known service and customer support was going to be like this I would have bought a Deus or Nox. I hope they get their act together as it seems like they are pulling out of the US market with the lack of customer service they have.

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Interesting....I have not saw anything like that. I do know that the covid  b.s. has caused a lot of stuff being imported in to the country is taking longer due to that. 

 

What was the coil doing that was so bad??

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When I first unboxed it I noticed it was unusually light for an 11" coil so immediately I did a quick depth test with my 7x11 then installed the 11", reset the factory defaults and put the same gain settings back on and noticed there was no real difference in depth between both coils.

I took it to the local park and numbers weren't all that consistent, even clad was a bit jumpy. I dropped the gain down to try to stabilize it and it had little effect.

Previously to purchase back in May I had asked Nokta the weights on the coil as I didn't want to buy a boat anchor. Months ago they returned my message that the AF28 weighs in at 540g. With that bit of info I tossed my 7x11 on the scale and it came in at 471g then the 11" and it weighed in at 492g.

Like I mentioned I believe the coil is actually a Simplex stock coil but miss labeled. I think it is an easy mistake but not good for the Kruzer customers that want to upgrade. I can't imagine how many of the wrong coils there are out there and it is unfortunate as the customers will be getting a seriously missmatched coil and have no performance gain on upgrade.

The dealer will hopefully clarify this and notify Nokta and maybe Nokta might do the right thing and do a replacement to those that had purchased the bad coils.

I have an email out to the GA tech center and the main tech support on a previous question and it still goes unanswered. I had to do an RMA on the coil with the dealer in this case because I do not want to get stuck with the coil and only have a 30 day window. Nokta support has been horrible and I can't blame the virus as emails can be answered off a Lazboy on a laptop. No excuse for lack of corresponance with their loyal customers. If they seriously want to survive in this competitive market they really need to pay attention to their qc and customers. Dumping faulty equipment out and ignoring customers is a easy way to kill a business.

So my advice on this if your looking at the 11" coil you may want to go for the 13" as that is unique size to the Kruzer and Amphibio line.

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Kac, mine weighs in at 490g, I'm not having any depth issues at the moment. Maybe the newer 11'' coils are lighter and they just didn't upgrade the spec sheet or maybe the old spec was a typo. maybe the coil is bad like my old one was. I wish i weighed my old one but its to late.  Good luck with the next one.

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If someone has a simplex, could they weigh the coil?

Depth of an 11" coil should be noticeably deeper than a 7" coil with the same gain settings. That is a big red flag for me that something is wrong.

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Well there is a thing as bad coils. I have one coming this saturday but it would be a couple of days before I could give you any test results on performance. I am very please with the Kruzer so far.

 

I saw on youtube a fellow say that the 11 anfibio coil put on the Kruzer was a deeper combo than the anfibio with the 11 coil on it.

Has anyone heard this?

 

I no longer have an anfibio. The anfibio is a great unit but the shaft is just way too heavy. I love the weight of the kruzer and it has enough settings to keep me happy.

 

I have the 9.5x5 elliptical on the Kruzer currently. Man is it a great combo for getting around tight spaces. About the best size I have ever had for that.

 

 

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On 9/29/2020 at 11:00 AM, kac said:

I just got my 11" coil in and it seemed super light. Comparing it to the stock 7x11 that weighs 471g w cover and cable the 11" coil only weighs 492g with cover and cable.

Depth wise the 11" seems almost the same or at least air test I can't really tell.

Did they reduce the amount of copper in the 11"? Tech specs say it should weight 540g.

Sounded like a fun calculation -- ratio of weights of copper for two different coils.  Now, I made a lot of assumptions and I don't know how good those are, so please keep that in mind.

Assumptions:  mono coils (already inaccurate for IB/VLF search coils), typical simple winding (as opposed to the fancy spiral windings now available on some more recent PI coils), same wire size used in both coils' windings, same electromagnetic inductance (I think this is a requirement for properly tuned detector-coil configuration), 7"x11" coil is a true ellipse (calculation probably insensitive to this assumption if it's anything close) and 11" coil is a true circle (ditto).  The assumption that the wire used is identical (other than length) may be the biggest weakness of this simple comparison.

The loosest approximation says the ratio of copper weights is (smaller coil divided by larger coil) equal to the square-root of ratio of smaller coil perimeter dimension to larger coil perimeter dimension.  For the two coils you quote (and assuming dimensions quoted are of the actual copper coils, not the enclosures/housings) it comes out to 0.91.  A better approximation includes some sqaure-roots of natural logarithms of functions that depend upon the actual wire used, but that's a weak dependency so the expected weight ratio then comes out to be ~0.92 for coil wire guages in the ~20-32 AWG size.

Now, how much does this help you?  The weight of the housing (and coil covers if included) are also going to contribute, and not in such an easily calculable way.  Throw in the possible flaws in the assumptions (e.g. mono coil vs. DD or concentric coil) and I'm thinking "not so much".

I wonder if measuring the inductances of the coils (two for each searchcoil) would help?  I.e. should they match?  (For mono coils as mentioned, I think the answer is 'yes' but I don't know if that carries over to concentric or DD coils.)

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I got in tough with the GA suport guy though he had very little knowledge on the weight and performance of the coils and had no knowledge of any spec changes since May. He also stated that there is no way the windings of a Simplex would be at all compatible with the Kruzer or Amphibio machines.

He did argue that air test or ground test won't dictate the depth of a coil which makes absolutely no sense to me at all. Here is why I say that. Of the machines I have and the coil versions I have when the width of a dd coil is larger on the same machine the wider coil will ALWAYS have more depth. There are times wider coils can be counter productive especially in high mineralization. It is completely pointless to argue or make a 11" wide coil that will have the same depth as a 7" wide coil. Either there is a design flaw in the updated design OR Nokta is selling a sub par upgrade to the Kruzer users. I consider the current 11" coil to be a piece of junk and a waste of money. I have enough experience to know when something is not right and do not like how this issue is being shrugged off.

I don't regret my Multi Kruzer purchase nor my recent Gold Racer purchase but seeing how a company has turned leaves me with little confidence in my purchases. Would I buy another Nokta machine? Highly unlikely.

I am still waiting on information about wireless compatibility of my Makro headphones and the Gold Racer that ON THE BOX INDICATES IS COMPATIBLE WITH THE HEADPHONES I HAVE. Yet there is no way of connecting them. There IS NO INTERNAL WIRELESS TRANSMITTER. THERE IS NO PORT FOR A WIRELESS DONGLE. THERE IS NO LONGER A WIRELESS DONGLE AVAILABLE. I was told th EZ Wander is not the option for this. I am really curious on how this gets resolved.

 

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