diy coil how?

[Point]

Hello, im new on this and i have a cheap PI MetalDetector at home with a 200mm Coil.
so far i have think to make a diy 280mm one. how do i calculator how much wind i will need?

Greeting Point
PS: sorry for my poor english its not my native language.

[WM6]

It depend of your coil design: regular "bundle" wound, spiral or some other shape.

But most probably you decided for usual "bundle" wound coil.
In this case 28cm coil you need about 24 turns of 24AWG wire (or 0.5mm in diameter wire CuL)

[Point]

It depend of your coil design: regular "bundle" wound, spiral or some other shape.

But most probably you decided for usual "bundle" wound coil.
In this case 28cm coil you need about 24 turns of 24AWG wire (or 0.5mm in diameter wire CuL)

ty but how to calculate it?
and will it work with 0.4mm wire too, with more turns?

[WM6]

To calculate your coil you can use one of different on-line Air Core Coil Calculators (Google this terms).

Targeted inductance is about 330uH.

With 0,4mm wire you do not need to change anything as well with 0,6mm.

One turn more or less is not so important, more important is to adapt your coil to RX input by proper selecting damping resistor.

[raygdunn]

Alternatively you could download our improved forum coil calculator

http://www.geotech1.com/forums/showt...067#post130067

Ray

[Point]

Alternatively you could download our improved forum coil calculator

http://www.geotech1.com/forums/showt...067#post130067

Ray

Hey Ray i have checked this calculator but the calculator say to get the arround the 330uH i will need 12.5 rounds
maybe i use use the calculator wrong?
stats thats i have enter
280
0.4
12.5

output:
280.71
1.41
0.34

[Qiaozhi]

Hey Ray i have checked this calculator but the calculator say to get the arround the 330uH i will need 12.5 rounds
maybe i use use the calculator wrong?
stats thats i have enter
280
0.4
12.5

output:
280.71
1.41
0.34

You've entered the diameter of the coil instead of the radius.

As it says in the coil calculator introduction ->
One common mistake is to enter the diameter of the coil, instead of the radius, into the first field of the dialog box.


Note: I have now changed this statement to bold in the introduction, as a few people seem to miss it.

[WM6]

Alternatively you could download our improved forum coil calculator

http://www.geotech1.com/forums/showt...067#post130067

Ray

Thanks for link.
As I see it is at starting header point of Coil forum (OK logically).
But when I am searching forum for "coil calculator", to get to "Point" a link, I didn't get it, at least not at 1st page of search results. I don't know why?

[Point]

yea i have thinked it too so enter it wrong... and have tryed allready with 140mm 0.4mm 19 turns = 0.337mH.
is it right so far?

One more points when i make 2x2 for rx and tx stay the µH at same? or is it then *2?
19turn -> cut -> 19turns again cut -> connect on board.
and will it bring any advance or is it more waste CU?

[WM6]

2x2m coil?
For what model of PI detector?

337uH is good result with coil inductance.

[Point]

2x2m coil?
For what model of PI detector?

337uH is good result with coil inductance.

the coil is for a noName "miltenberger snooper sxc5.1".
Not 2x2m i mean like this here https://www.youtube.com/watch?v=ovxfcG59bWo at 2:33min there you see 4wire clamps to make 2times x Turns.

[bernte_one]

hello 1Point (same Name on Schatzsucher.org right?)

the snooper isn´t a simple pi detector
it is a vlf metal detector with separated transmit and receive coil
so you have to make two coils with different specs
the receive coil (rx) has a higher inductivity than the transmit coil (tx)

if you are interested in coil making look there
https://sites.google.com/site/dbcoilshells/home

it is the site from don bowers
he is also here in geotech at dfbowers

[Point]

hello 1Point (same Name on Schatzsucher.org right?)

the snooper isn´t a simple pi detector
it is a vlf metal detector with separated transmit and receive coil
so you have to make two coils with different specs
the receive coil (rx) has a higher inductivity than the transmit coil (tx)

if you are interested in coil making look there
https://sites.google.com/site/dbcoilshells/home

it is the site from don bowers
he is also here in geotech at dfbowers

But a PI have 2Coils too or im wrong? from some Schematics i have see there are 2.
sure i know there are MonoCoils out too.
thanks for the link but i dont will do via vacum i will ABS Print it then but for the stats is it not bad at all.
how much highter is the inductivity?