New for 2017. Carbon Fiber search coils for Nexus Standard MP.

[Nexus]

I have the pleasure to introduce the first in the world Caron Fiber composite search coil manufactured for Induction Balance metal detector. The coil on the pictures below is 45" in diameter and weight 1.4 kg. Sampling frequency 5.3kHz.


Coming soon from our Carbon Fiber series search coils are 20"DD and 26"DD.





For comparison 45" concentric next to 13"DD.



Further technical information will follow.

[kt315]

depth on gold plate 15x15cm?

[Nexus]

depth on gold plate 15x15cm?

On the mentioned 15 x 15 cm metal plate (the actual metal is irrelevant) the maximum guaranteed depth in ideal conditions will be 120 cm in ground. The mentioned ideal conditions are - No iron around, flat ground surface without any pot holes (like a disced field), very dry soil as concentric coils are inherently sensitive to mud.
In average conditions the maximum depth would be up to a meter in the soil in the absence of Iron nearby.

[WM6]

........as concentric coils are inherently sensitive to mud.

I tested model Nexus Standard MkII. It sense differences in pure soil: between trampled down soil lanes and normal pasture soil.
Suppose that mentioned MkII model such a big coil would not survive. Hope that MP model is set to be less border sensitive.

[mschmahl]

This combination with big coil look´s like a great hoard-hunter.

[Funfinder]

Great job - a large coil but still lightweight enough so someone can handle it.
70cm would be already good as standard deep coil but 115cm is for real depth.
The question is how the concentric design compares with DD but I guess its pretty
good under such conditions. Probably it will stronger ignore surface near smaller objects
of ca. 3cm but this way someone is undisturbed to concentrate on the real deep and large stuff.

Happy New Year and much success with it!

[Nexus]

Great job - a large coil but still lightweight enough so someone can handle it.
70cm would be already good as standard deep coil but 115cm is for real depth.
The question is how the concentric design compares with DD but I guess its pretty
good under such conditions. Probably it will stronger ignore surface near smaller objects
of ca. 3cm but this way someone is undisturbed to concentrate on the real deep and large stuff.

Happy New Year and much success with it!

Thank you Funfinder.

There is actually a mistake in the stated diameter of the coil in inches ( as I am use to meters, centimeters ect). The correct figure is 41" not 45. So in cm will be about 104 cm diameter.
There will be a DD with an average diameter of 66 cm - 26" not long from now.
With the Nexus Standard MP the big concentric coil have demonstrated so far the best sensitivity and depth. Before involving Carbon Fiber in the construction huge DD coils were impossible to manufacture with an acceptable weight and they have also proved to me real hell to keep stable. It remains to be seen how things will turn up with the Carbon Fiber, but there are some other materials that will aid the design if necessary.

This 41" coil does not actually miss small objects, which some may consider a disadvantage. It slams a Victorian Penny at 20" in the soil and small coins around 18mm at 12 to 15" with crazy signal level. There is however a considerable difference between large deep objects and small objects at shallow depth in the time constant of the signal, which makes it quite easy for one to distinguish the big stuff.

The weight of the coil can drop to about 1 kg, but at the cost of a considerably more complicated design and manufacturing process.

[Funfinder]

Everything fine!

But my really genius idea you can check out by some tests is: using two pretty small coils from a distance of 70cm!
Such a coil even can reach the smallest cave-crevices and goes through woods, stony areas and bushes like butter.
It also could be made very stable, lightweight and good transportable. And also some vibration could be very useful!




> 66 & 105cm

No prob 5cm less or more. 66cm is already a big advantage compared with all those still too small 40 or 45cm coils for reaching great depth.

What might be an additional improvement is to mod the coil a bit from circle to egg or elliptical shape for terrain full of bushes etc.
As long as it doesn't reduces depth too much. So the 66 & 105cm coils also are easier to transport.




> It slams a Victorian Penny at 20" in the soil and small coins around 18mm at 12 to 15" with crazy signal

WOW! This is fantastic! Seems the inner coil already gets far out of balance by such small objects. Super!




> in the time constant of the signal, which makes it quite easy for one to distinguish the big stuff.

In this case it is no disadvantage at all but perfect, because the detector outputs some longer signal -
compared with those annoying all the time the same short Garrett etc. beeps.

[Nexus]

Everything fine!

But my really genius idea you can check out by some tests is: using two pretty small coils from a distance of 70cm!

Small coils can not get deep enough, because a small TX does not have long enough radiation with useful intensity. TR configuration were never my passion as they do not exhibit sensitivity to targets that I am interested in.

66 & 105cm

No prob 5cm less or more. 66cm is already a big advantage compared with all those still too small 40 or 45cm coils for reaching great depth.

What might be an additional improvement is to mod the coil a bit from circle to egg or elliptical shape for terrain full of bushes etc.
As long as it doesn't reduces depth too much. So the 66 & 105cm coils also are easier to transport.

As I have established long ago marginal increase in diameter of a coil does not lead to significant increase in depth. Double diameter of a coil will result in 50% air sensitivity and only 25% real depth penetration in ground. To double the depth of any detector it is required to fit it with a coil that is 64 times bigger in surface area or 8 times the diameter of the original coil.
My main objective with the Carbon Fiber coils is low weight relative to absolute size, which will result in higher productivity.

It slams a Victorian Penny at 20" in the soil and small coins around 18mm at 12 to 15" with crazy signal

WOW! This is fantastic! Seems the inner coil already gets far out of balance by such small objects. Super!

> Unfortunately too small for my taste. I wish it was a bit less sensitive to the small stuff, but then there will be less sensitivity to the small (below 1kg) hoards as well.

[/QUOTE]

[kt315]

ok. how about of a name on the coil now? there will be necessarily a word GOLD just cause without the word
you will not get the success in adwertizing. thats sweetty word for majority. GOLD PHARAOH. or GOLD EAGLE. oops there had been golden mask! BAD!
ELDORADO GOLD is nice!

offer your name.

[Nexus]

ok. how about of a name on the coil now? there will be necessarily a word GOLD just cause without the word
you will not get the success in adwertizing. thats sweetty word for majority. GOLD PHARAOH. or GOLD EAGLE. oops there had been golden mask! BAD!
ELDORADO GOLD is nice!

offer your name.

Well then, I am open for suggestions.

The coils profile resembles a wheel of an ancient chariot, so how about a Gold Chariot or a Grand Chariot?

[Funfinder]

You can name the 1 meter coil: Golden Sun
Paint the inner ring together with the rays golden and it looks really luxurious!

btw. do you know how sunny it is in Bulgaria or better how much snow in winter?
I guess January and February will be the most snow, no matter if Sofia or Varna.


Thanx for the infos. I didn't thought about TR but IB with the two distant but still very
inductive small coils. Would be a question of stability and sensitivity how good it works.

Another interesting deep coil method is to place the DD for the 66cm up-downwards!
In earlier times you built 2 circle coils left-right so you just turn this for 90° and voila.
This way each part of the DD coil can keep almost its circle form or you
can make them egg-shape overlapping so the total coil looks elliptical.

Anyways, its fantastic that you built the 1m & 66cm coils and I'm
interested how it compares with all those pretty unstable PI 1m coils.
I am sure the results will be better and especially the discrimination, too!

[kt315]

Well then, I am open for suggestions.

The coils profile resembles a wheel of an ancient chariot, so how about a Gold Chariot or a Grand Chariot?

vote for Gold Chariot! nice choice!
i receive every day letters and all of them have the magical HOLY word GOLD! ALL!!!
this word has written in DNA of those people by God himself i believe! thats hard fact!

Hello If you have any information about the construction of the metal detector and gold detector professional and efficient servant put Thank you very much

[chevesne]

Well then, I am open for suggestions.

The coils profile resembles a wheel of an ancient chariot, so how about a Gold Chariot or a Grand Chariot?

[Funfinder]

I know Chariots Of or On Fire but not of gold - those are war-tools.

But the sun is big and stands for a prospering life! Ra was the god of sun at Egypt.
The sun which shines through the darkness of soil and reveals all the treasures!