Concentric coil for TGSL.

[Koala]

I use a 5.5" concentric without a pinpointer for several years

A hole dug with a small boarder spade is just big enough to fit the coil in.

Works 90% of the time. .22 cartridges in the grass roots are a pain though and requires the clod being ripped apart.

With a 8" concentric I also rarely need to use a pinpointer. However a pinpointed does speed up the recovery.

I bought the GP pointer from Banggood. Works really well and for the price its not worth building one if you include its packaging.

[Virdi_248]

Hello, I have created laa bobbin of 8 " with thread of copper of 0,3mm and the bobbin is a bit unstable.

How many returns are the correct ones for thread of 0,3mm in bobbin of 10 "? I do not have possibility of obtaining of 0,25mm. I want to do the bobbin of 10 " now.


On the other hand in the video of youtube the bobbin not for of doing noise. Is it for the land or for that this the land fills of scrap?

[Goaty]

I bought the GP pointer from Banggood. Works really well and for the price its not worth building one if you include its packaging.

Hi Koala
Sounds interesting Can you give more details please? - sensitivity etc.
Thanks

[Hyena]

Hello, I have created laa bobbin of 8 " with thread of copper of 0,3mm and the bobbin is a bit unstable.

How many returns are the correct ones for thread of 0,3mm in bobbin of 10 "? I do not have possibility of obtaining of 0,25mm. I want to do the bobbin of 10 " now.


On the other hand in the video of youtube the bobbin not for of doing noise. Is it for the land or for that this the land fills of scrap?

Hi, 0,25 or 0,3mm does not matter.


Number of "returns" depends on Tx : Rx diameter ratio.


Read this: http://www.geotech1.com/forums/showt...373#post164373


Noise is often caused by mains 230V near in the wall. Did you shielded that coil? With shield and on field (far from mains and high voltage wires) it will be silent.

[jladre]

I bought the GP pointer from Banggood. Works really well and for the price its not worth building one if you include its packaging.

i got mine for $36. Its not really worth to build one with that price.

[Goaty]

Koala -
I tend to agree - at the moment I have too many unfinished projects underway!!!

Which GP pointer are you referring to from Bangood? - is it the Barui GP-101 they have advertised at the moment?

[Virdi_248]

Hi, 0,25 or 0,3mm does not matter.


Number of "returns" depends on Tx : Rx diameter ratio.


Read this: http://www.geotech1.com/forums/showt...373#post164373


Noise is often caused by mains 230V near in the wall. Did you shielded that coil? With shield and on field (far from mains and high voltage wires) it will be silent.

Thank you.
How do you suggest I put the shield? My intention is to put aluminum foil cheap.

[Hyena]

Thank you.
How do you suggest I put the shield? My intention is to put aluminum foil cheap.

Well, I tried aluminium and rejected it instantly. I use aluminium on DD coils. On DD this foil changes inductance a bit. But on concentric this shift was so big, I was not able to null and use it. So for CC i always use graphit spray.

EDIT: I noticed your long loops. Use as short wires between Tx and its backing as possible. In the end every wire is better when it is shorter

[Virdi_248]

Now the threads are mas short and I have tied the bobbin with rope. The bobbin to improved very much being mas stablly in way discrimination though the depth is not great, 17cm for an Euro.

On the other hand my intention is a bundle of wood does type sandwich. If civil servant painted the wood with graphite? The wings estaran closed with foam of polyurethane.

[saber]

Hi

i need a concentric coil for quasar arm with 0.45 wire

please help me

thanks

[Hyena]

Hi

i need a concentric coil for quasar arm with 0.45 wire

please help me

thanks

Help with what?

[saber]

Concentric coil details

[Hyena]

Which details? There are so many variables... Answer to your "question" could be long as toilet paper.

[Virdi_248]

I almost got the metal detector I've been chasing for a long time thanks to the 10 "concentric coil. It has worked better than the 8" in my case. The bad part is sometimes with noisy roots but it is acceptable. Overall I am happy, punctuated this 7.5 / 10 coil and bearing in mind that it is not shielded. I leave a picture of my detector. Thank you for sharing knowledge.

[ne555]

Hi don the back copper in rx Parallel or sequential?? [IMG][/IMG]