Concentric coil for TGSL.

[Hyena]

Hi

i need a concentric coil for quasar arm with 0.45 wire

please help me

thanks

Help with what?

[saber]

Hi

i need a concentric coil for quasar arm with 0.45 wire

please help me

thanks

[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.

[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]

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.

[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?

[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.

[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.

[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

[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?

[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.

[homefire]

DB ! What is the smallest Round housing you make ? 6" . I'll be using some of these Idea's for a 6" Concentric for my GMT I think.

[BKY1337]

Ok, i want to make a concentric one because i have no pinpointer and its very hard to pinpoint things with my DD coil.
But i dont like to change the coils. I have thought that it is like something between. Maybe its better to build a pinpointer.
But i definately will build a concentric one because it looks like its very light without the resin. My DD has about 600g.

I think you can sweep the coil again 90 degrees turned to pinpoint things, this doesnt work with my DD coil , maybe because of the big magnetic field
of the D coils. Maybe its smaller with this elliptic concentric coil but i dont know.

[Koala]

Do you guys think this pattern is usable for a good pinpoint and widescan coil?

[ATTACH]39583[/ATTACH]

Usable yes

Best for pinpointing no

Coins at an angle will pinpoint somewhere around the top and bottom of the inner Rx ellipse which is further from the centre than a circle.


Separation is half the coil width so you will be able to detect nearer to large iron.




Not tried any different shapes on a VLF but did try square, oblong, triangle and so on with my PI. Circle was the best for both pinpointing and depth. Elliptical preforms the same as a circle of is smallest width but with greater coverage top and bottom.


Always wondered how the fisher concentric coil with a circle Tx and elliptical Rx fit in

[BKY1337]

Do you guys think this pattern is usable for a good pinpoint and widescan coil?