2 layer primary puzzle

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Original poster: "James T by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jamest2000-at-att-dot-net>

Hi Everyone,
 I will keep this brief. I am working on an 8" coil with a 2 layer primary.
I have constructed the primary and
it is not behaving as I expected. I measured the inductance of the primary
by itself.
  What happens is, I measure from the outside of the top coil to the inside
and the inductance goes up as
expected. Then I drop down to the bottom layer and measure from the
top/outside to the bottom/turn, oops, the
inductance goes down as I go out. The inductance of the bottom coil seems
to cancel the inductance of the top
coil. Please set me straight on this.
1.understanding/myth - the winding direction between the 2 coils is irrelevant.
2. understanding/myth - the "mutual inductance" of the 2 coils increases
inductance, not cancels out the
others inductance.
3. 2 layer primary's are a practical approach. I seem to recall some posts
on this, and it was considered
reasonable. Brilliant to ask now that it is done!
Any comments will help. Thanks,
 James Cart