Topband: Progress with ugly computer noise

[Paul Christensen]

> Total common mode inductance is 1 times L, not two times L. This is 
> because the windings are parallel with near infinite mutual coupling. It 
> is exactly like a bifilar filament choke.

Tom,

Run it in any SPICE variant as proof that in CM, total apparent inductance 
is 2*L.  For example, two 0.1H inductors:

subckt CommModeChoke InA InB OutA OutB
L1 InA OutA .1H
L2 InB OutB .1H
K1 L1 L2 0.99999999
.ends CommModeChoke

Connect a source to InA and InB with a load to OutA and OutB.

73,

Paul, W9AC