DIY Mad Litz Wire for ULTRA FAST PI Coils

[andybiker]

Hi,
I'm new to detectors but have radio and electronics experience.
I always thought that litz wire was used to reduce resistance due to skin effect at high frequencies as well as reduce self capacitance of the coil.
I have some multistrand silver coated wire that I thought would be perfect but apparently not?
I thought the ideal coil would be low resistance, low capacitance and driven to just below saturation.
years ago radio coils used to reduce capacitance (I hope I describe the following in a sensible manner)
You wind the coil on a round card with an odd number of slots, winding the wire in and out of the slots so that there is a gap between adjacent windings.
would this strategy work with a detector coil ?

[phred01]

Well, at least now I know the theory regarding the use or non-use of Litz wire for VLF detectors. Thanks.

What is LITZ wire anyway? I know there is a coated wire used for transformers. Could that be used?
Melbeta

Thinner and more wires the better radio litz wire is prefered
?

[dbanner]

[Andi68]

[dbanner]

Looks like absolute madness if something goes wrong.

[dbanner]

Here it is. The wires feed through the nozzle of the plastic bottle. Then I guess you have to twist them together with drill.

[dbanner]

I recently saw a simple rig for making litz wire. Somewhere on Russian metal detector review forum. Will see if I can find it again.

[Andi68]

http://www.elektrisola.com/hf-litz-wire.html

For example its used in transformers of Swichtmode powersupplies.

[Melbeta]

Well, at least now I know the theory regarding the use or non-use of Litz wire for VLF detectors. Thanks.

What is LITZ wire anyway? I know there is a coated wire used for transformers. Could that be used?
Melbeta

[phred01]

Thanks Joe,
I am not interested in Pulse detectors, but like the VLF machines. I am trying to glean all that I can in regard to making coils, so I am asking questions to learn what I can learn. What wiring is best for VLF machines?
Melbeta

Litz wire would help with VLF machines. the coil & a capacitor are part of an oscillator. The coil is made of two components .....inductance & effective resistance. By reducing the resistance by using litz wire The LC circuits Q is increased therefore smaller items can be detected more easily
L

[Andi68]

So I prefer to buy this litz wire before I go crazy with such housewife work

[bbsailor]

Thanks Joe,
I am not interested in Pulse detectors, but like the VLF machines. I am trying to glean all that I can in regard to making coils, so I am asking questions to learn what I can learn. What wiring is best for VLF machines?
Melbeta

This question is probably best answered by Carl or Qiaozhi.

The issues are usually related to operational frequency and reduction of losses to increase coil radiation and efficiency.

Joseph J. Rogowski

[Melbeta]

Thanks Joe,
I am not interested in Pulse detectors, but like the VLF machines. I am trying to glean all that I can in regard to making coils, so I am asking questions to learn what I can learn. What wiring is best for VLF machines?
Melbeta

[nonkapo]

Thanks, Joseph, i read about and your explanation in my other posts was more than clear. I just try to get which litz wire gauge corresponds to solid or stranded wire gauge. I mean if as you say awg30 is the maximum one should use is this valid for Litz as well?

[bbsailor]

This brings up a question in my mind. Would it be better to use a solid wire? If not, what kind of wire would you suggest?
Melbeta

The thickest solid wire I have used with a delay of about 8uS is AWG 30. This was a low power CS6PI that had a 39 Ohm resistor in series with the coil so carrying a high current was not an issue. If I had to use a thicker wire I would look at tinned stranded copper marine wire as there is a slight resistance between the strands and this minimizes the eddy currents forming in a thicker solid wire or silver plated strands that have a low resistance between strands that tend to support holding eddy currents longer. Try to find an insulation with the lowest dielectric constant to make a coil with minimal coil turn-to-turn capacitance. PVC insulation dielectric constant ranges from 4 To 6 while PTFE (Teflon) is 2 and PE is about 2.2.

I hope this answers your question?

Joseph J. Rogowski