Nexus Coil Design

[Max]

(but one my friend has a similar one, bulgarian design, homemade)

[ivconic]

Geo, you are abslute right!
Regards!

[Unregistered]

halo

halo effect is just salesman nonsense. coins fall down the hole as you dig, thats hoe they get deep

[Unregistered]

money back

just imagine trying to get your money back from grogy

[Unregistered]

just imagine trying to get your money back from grogy

Just imagine getting losers like you to leave the Geotech forum and salvage us from reading your mindless uneducated comments.

[Qiaozhi]

But there is statement i can not agree with;
"I asked Georgi Can machines that that don't air test well go deeper in the soil.He
said No absolute Crap !! this is scientifically impossible if a machine air tests badly
it will detect badly in the soil despite what you read on metal detecting forums and some manufacturers literature."

If you use a particular coin for an air test and then bury the same coin in the ground, all detectors will detect this coin further away in the air test. I don't think there is any dispute that this is a fact.

Yes this is true! Not "some" machines - but most machines will do! O.K. differences are

not big, but there are some differences. Otherwise, i dont know how to explain so much simillar situations when i dug item (coin) from 20cm depth, and minute after i cant detect same coin at 17cm in the air!? How do you explaining this!?
Only explanation is ; i am liar!? Am i? Yet this is unknown phenomena for me.
I noticed it few years ago. Was interested much about it an especially payed attention on it. So many times i performed simillar checks to establish some rules or discover what is all about - but without success!

What are you talking about here is someting different. I know this is a contentious issue, but I also have noticed this halo effect on a number of occassions. In some cases, with ferrous targets and copper coins for example, this is quite common. However, for gold and silver items it's harder to understand how this could happen. Sometimes with gold and silver items there could be a mistake with regard to actual depth. I'm sure we've all dug a big hole and had trouble locating the target, when in fact the object was in the side of the hole, and later falls to the bottom during excavation, thus making the depth appear greater than it actually was in practice.

BUT IT IS FACT WHICH NOBODY (NO NEXUS EXPERTS OR ANYBODY ELSE) CAN DENY! YES,VERY OLD

ITEM, SO LONG AGO BURIED IN THE GROUND WILL BE DETECTED DEEPER THAN IN THE AIR! DIFFERENCES FROM ONE TO ANOTHER DETECTION DISTANCE WOULD BE PROPORTIONAL TO SIZE AND
MASS OF ITEM - LARGER THE ITEM, BIGGER THE DIFERENCE BETWEEN DETECTION DISTANCES AND VICE VERSA.
So sorry if i confronted to you, but i experienced this so many times...i am prospector
too - not only constructor. Come to think; i am prospector for 20 years and constructor just for 10 years...!?
Phenomena or call it anyway you want - it exist,it is true....and i dont have clue what
is all about!? I can not explain it yet....
Again, good test, i am not suprised at all....keep it that way!
Regards!

I wonder how much of this is caused by compacted soil rather than disturbed soil. Has anyone ever tested whether there is a difference?

The Bandido has nowhere near the depth capability of the Nexus."

You are not familliar with phylosophy of metal detectors much, my friend!
Depth capabilities are mostly dependant on coil - not on detector itself!
So, why not? Bandido could be much better if used with XXL OO shape coil as Nexus...

You have misunderstood my statement. You said "Depth capabilities are mostly dependant on coil - not on detector itself!" which was exactly the point I was making!
In fact we are in total agreement.
If you were to put a OO coil on the Bandido, it would have improved performance. If you also made this OO coil fully resonant, there would be an even greater improvement.

But what are benefits from XXL coils??? Not suitable at all on most terrains....

The Nexus does not rely only on XXL OO coils. One of Georgi's favourites is the 4" coil. http://www.nexusdetectors.com/Access...sproducts.html
It can detect a 30mm coin at 14" in real soil conditions!
So there is no need to worry about the difficulty of getting that strange OO coil into difficult places. I have personally used the 4" coil and it's quite incredible how deep it can go. Ivconic - try making one of these yourself. It looks really silly on the end of the detector stem because it's so small, but you'll be surprised.

OK, friends, at some point all of you are right! i can partially agree with all your

claims. No need to argue here.

Absolutely true. I think we are all in agreement for once!

OO coil shape is most strange design i met. I tried to make OO coil for my TGS and

later it showed excellent performances. Yes it is very sensitive and deep setup.
I cant beat depths managed with OO coil on TGS, later with any of DD coil i made...
So, although i am not familliar at all with Nexus, i can see cleary that OO coil
applied to any descent detector can turn it to much better device...It is fact!
But, as benefits, OO setup has drawback too! Main drawback is shape not suitable
to approach to some hard spots on the field. I already posted this in TGS thread.
On leveled terrains OO shape is just perfect!
As coin prospector mostly, i am pushed to "infiltrate" in closely bush, tree roots,
stones....poky,snug places...so hard even for small DD coil. At these spots OO coil
is almost unusable....easy miss coin or other small item...

As I said above, try making a 4" coil.

I think it would be very interesting to try and understand this "halo" effect. Is it real, or just a case of bad measurement? Maybe it's something to do with compacted versus loose soil matrix, or oxidization of the target item. Maybe it's a combination of all three?

[tiktak]

Qiaozhi

If you also made this OO coil fully resonant, there would be an even greater improvement.

Hi,
Qiaozhi
How you do this?fully resonant?

[tiktak]

Hi,

Max,
How much turns did you use for your 12cm OO coil?
I wish to try this too.
Thanks

[Max]

Max,
How much turns did you use for your 12cm OO coil?
I wish to try this too.
Thanks

Hi,
read Ivconic's posts about. He made these before me.
You'll find any data there.

Best regards,
Max

[Qiaozhi]

If you also made this OO coil fully resonant, there would be an even greater improvement.

Hi,
Qiaozhi
How you do this?fully resonant?

That's the Nexus secret my friend.

[Max]

If you use a particular coin for an air test and then bury the same coin in the ground, all detectors will detect this coin further away in the air test. I don't think there is any dispute that this is a fact.


What are you talking about here is someting different. I know this is a contentious issue, but I also have noticed this halo effect on a number of occassions. In some cases, with ferrous targets and copper coins for example, this is quite common. However, for gold and silver items it's harder to understand how this could happen. Sometimes with gold and silver items there could be a mistake with regard to actual depth. I'm sure we've all dug a big hole and had trouble locating the target, when in fact the object was in the side of the hole, and later falls to the bottom during excavation, thus making the depth appear greater than it actually was in practice.


I wonder how much of this is caused by compacted soil rather than disturbed soil. Has anyone ever tested whether there is a difference?



You have misunderstood my statement. You said "Depth capabilities are mostly dependant on coil - not on detector itself!" which was exactly the point I was making!
In fact we are in total agreement.
If you were to put a OO coil on the Bandido, it would have improved performance. If you also made this OO coil fully resonant, there would be an even greater improvement.


The Nexus does not rely only on XXL OO coils. One of Georgi's favourites is the 4" coil. http://www.nexusdetectors.com/Access...sproducts.html
It can detect a 30mm coin at 14" in real soil conditions!
So there is no need to worry about the difficulty of getting that strange OO coil into difficult places. I have personally used the 4" coil and it's quite incredible how deep it can go. Ivconic - try making one of these yourself. It looks really silly on the end of the detector stem because it's so small, but you'll be surprised.


Absolutely true. I think we are all in agreement for once!


As I said above, try making a 4" coil.

I think it would be very interesting to try and understand this "halo" effect. Is it real, or just a case of bad measurement? Maybe it's something to do with compacted versus loose soil matrix, or oxidization of the target item. Maybe it's a combination of all three?

Hi,
"The Nexus does not rely only on XXL OO coils. One of Georgi's favourites is the 4" coil"

maybe now it's so...

he said some time ago that Nexus uses just 1 type of coil the BIG one... now there are many more ? Nice.
Maybe he realized what me and Ivconic are talking about here... big OO are unusable in some places, like you stated now.

Hard to belive but seems that you agree with me at least one time!

Maybe you suggested him making smaller coils ?

4'' OO ? each coil is then 10cm diameter.

"It can detect a 30mm coin at 14" in real soil conditions!"

Well ehm... don't know how to say that...I have to made a 4'' OO to say how my homemade BandidoII goes with that coil type and dimension on soil...

But
man... I have a sad news for you !

My homemade BandidoII detect a 30mm coin at more than 14'' in the ground with 12cm diameter OO. 14'' are 35cm , right? I detect a 30mm coin at 38cm with OO12 in the ground. My coin is made of a silver alloy. It's 30mmx2.5mm, a bit smaller than 1/2 crown of 1967 that is 32.5mm in diameter.

So not much difference I think...I have a bit greater OO.

So I was right on everything here !

How that's possible ???

Cool !
Can I start a company now !?

Guys, follow my advices:
- if you aren't skilled with soldering iron find the money and buy the Nexus, or any other good one...
- if you are skilled and can make a good coil and solder some stuff, tuning... build a TGS... you'll find everything you need in the posts by Ivconic (OO coils) and others...

One way or another it's up to you !

PLEASE DON'T ASK ME ABOUT HOW MANY TURNS ETC... YOU'LL FIND EVERYTHING THERE.

Kind regards,
Max

[J_Player]

Hi Qiaozhi,

Has any testing been done with the Nexus in difficult hot soil like found in the Australian gold fields? I am curious to know about the discriminating abilities in the iron rocks that make it nearly impossible for most PI detectors to find the deep gold nuggets there. Currently, Minelabs makes the only PI detector that gives much success in these fields. But I was wondering if the Nexus can perform there as well as these PI detectors in the iron soil found in Australia.

Best wishes,
J_P

[Qiaozhi]

...he said some time ago that Nexus uses just 1 type of coil the BIG one... now there are many more ? Nice.
Maybe he realized what me and Ivconic are talking about here... big OO are unusable in some places, like you stated now.

Actually Georgi has made many different sizes of coil, but the first detectors all used the same size.

Maybe you suggested him making smaller coils ?

No - Georgi thought of it all by himself.

My homemade BandidoII detect a 30mm coin at more than 14'' in the ground with 12cm diameter OO. 14'' are 35cm , right? I detect a 30mm coin at 38cm with OO12 in the ground. My coin is made of a silver alloy. It's 30mmx2.5mm, a bit smaller than 1/2 crown of 1967 that is 32.5mm in diameter.

Well Max, you must a master coil constructor.
Exactly 51 minutes after I posted that information you managed to read my post, dash to the workbench, construct a 4" OO coil, go out in the field to do some testing, then return to post your own reply about the superiority of your new coil. Bloody amazing...

Can I start a company now !?

Well at least you'll be able to make coils quicker than Georgi.
Perhaps you can give him a few tips?

PLEASE DON'T ASK ME ABOUT HOW MANY TURNS ETC... YOU'LL FIND EVERYTHING THERE.

No comment.

[Max]

Actually Georgi has made many different sizes of coil, but the first detectors all used the same size.


No - Georgi thought of it all by himself.


Well Max, you must a master coil constructor.
Exactly 51 minutes after I posted that information you managed to read my post, dash to the workbench, construct a 4" OO coil, go out in the field to do some testing, then return to post your own reply about the superiority of your new coil. Bloody amazing...


Well at least you'll be able to make coils quicker than Georgi.
Perhaps you can give him a few tips?


No comment.

Hi,
"Well Max, you must a master coil constructor.
Exactly 51 minutes after I posted that information you managed to read my post, dash to the workbench, construct a 4" OO coil, go out in the field to do some testing, then return to post your own reply about the superiority of your new coil. Bloody amazing..."

I've not made in 51 minutes... about two hours for wounding, shielding and nulling... big problem was sealing and keep it fixed. About 1 week cause had to wait for some epoxy to arrive.
Already done about 1 month ago in some spare time.

And my coil is not 4'', read better, is 12cm diameter for each O coil. More than 4''. So I admit I can't compare my stuff with Nexus-4''OO coil results, cause I need exactly same dimensions to compare... and have no time for these BS at now...also I haven't any Nexus to compare with on my test garden.

"Well at least you'll be able to make coils quicker than Georgi.
Perhaps you can give him a few tips?"

I don't need much time to do them cause are just coils. No black magic... no secrets, just coils. I don't know what he have to do...I don't know why he need more time... maybe alignement or resonance... I'm not interested at all in that. It's his problem if have hundreds of volts on oscillator, I haven't.

My idea is that what Nexus does brute-force... my BandidoII-clone does with a good tuning and a lower noise.

Anyway, if you want belive that only Nexus could find a 30mm diameter coin underground at 14'' (35cm) with its 4'' OO coil... do so.

Not my problem if you have self-convincements about that.

Kind regards,
Max

[Esteban]

For me the best detector is the detector that has everyone of us

Geo is right and I add: The best is the detector used properly. I see persons with excellent MD, and I gain them with my homemade. EVER!!! Experience, come here!!!