In my country (EU) continental Europe, ISO standard applies and decimal comma is , (Pi is 3,1415 not 3.1415).
As you may have noticed English is not my native language and in my native language is on coils turns and thread the same expression. In English, I try to use a turns for coils , but when writing the post I solved engineering stuff and the metric thread is thread.
Specifically
Here is a photo of coils with 1.2mm wire
One picture per thousand words
why do I ask at all?
Basically, we have 4 coils
wire length 4x25cm = 1m
Current 2A frequency 15MHz
When the skin effect is taken into account, there will be AC resistance
268mOhm for 1m 1,2mm wire because Skin Effect Depth is only
16,8um
for 4x 0,7mm 464mOhm / 4 =
116mOhm
for 120x0,1mm 3742mOhm/ 120 =
31mOhm
Logical clear, there is nothing to solve, but
-the wire is strong, holds well on the toroid (see pic) , stranded wire (120x0,1) it is soft and flexible will not hold well on the toroid this will worsen the coil properties
- Proximity effect applies to multiple conductors somehow it will worsen the coil properties
- RF litz wire 120x0,1 is about 5 times more expensive than 1.2mm wire
I just don't know what to use as optimal solution.