Air core coil info for Kevin and all.
To clarify my coil, the 1.2" is the axial length of the coil. It is
quite short in length and quite wide in diameter (4.1"). It looks a
bit like a loop antenna. I'm not sure if it is "within spec" on the
L/D ratio to be a true loop. I forget that criteria. The longer a
coil gets in relation to its width, the less signal pickup or
radiation it will have.
It is not a typical basket wound coil. One of the Xtal Set Society
guys developed this method of winding where a length of thin wall PVC
has deep slots cut into it lengthwise on one end so that it resembles
the top of a castle peice in chess. The coils created with this form
ended up with the name "rook" coil. I decided to call mine a
basketweave to avoid confusion, but have not succeeded! So now you
know the whole story (apologies to Paul Harvey)!
The 4.1" dimension is the width of the coil measured across it from a
point half way between the inner and outer layers of wire. This
layer distance is only about .2".
Unlike some true basket coils, the turns do not come way in toward
the axis before bending back out. They are quite shallow between
layers. Mine is wound one under, one over -- nothing fancy.
After winding, hot glue is applied across the wire cross-over points
and the form slipped off.
Hope this makes things more clear.
near Syracuse, NY