[Lowfer] Coil Calc 2

[Peter Barick]

LowFers,

Still thinking about Loading Coils, though differently appearing ones.

I saw on a Brit Web site a large 136 kHz coil that I think had two or
more layers of space-wound turns, a solenoid within another. Made with
heavy covered wire, it was a large affair covered w/ appropriate
trash-type container.

Is this a compromised or acceptable way to achieve L and good Q? Then
can L be thought of as the sum of the sub Ls, or is there some
interaction beyond that of mutual C?

My guess: it is the sum, as in the use of a vari coil, but then the
vari is usually taken to be a small, tuning portion, not a major
component of the coil.

Further, can the AWG coil calcs be made on each component and summed
for total L, as usual?

One other point: If the above regarding a multi-layered solenoid is
acceptable practice, then can it also be extended to what I'll call
"bird's nest" coil construction, i.e., insulated wire wound around a
former without regard to order? On this one I'm uncertain as I haven't
seen it practiced, but it too could be considered a "multi-layered"
solenoid coil.

Comments?

Peter