[Elecraft] Another feedline question

[Stuart Rohre]

Loss is related to the dielectrics in the RF field, and how lossy is the
dielectric.  True open wire line is almost lossless, as it has mostly air
between the wires carrying RF.  Coax lines have the higher losses than any
of the parallel lines because of the close spacing of the conductors to the
dielectric and it has to pass thru thicker dielectric layer between center
wire of coax and the shield.  Maybe I better qualify that comment on coax,
as there are air insulated large coaxes in broadcast use that have low loss
spacers.  They may well equal some fully insulated parallel lines.  It is
the plastic continuously insulated coax I am saying has the greatest loss.
-Stuart
K5KVH