Topband: Using RG-6 for 160m transmission purposes

[Tom Rauch]

 The celluar polyethylene dielectric stuff is normally 78%.  If you have the
type similar to Belden 8215 (double shielded polyethylene dielectric) the VF
is 66%.

Solid polyethylene is around .66, but foamed cables can actually vary
between .66 and around .90 depending on the ratio of air to poly in the
insulation.

Good cables like 7/8th inch 50 ohm, and .625 75 ohm power rated cables, are
up around .9. Cheap foam cables like off-brand RG8X are often around .75 or
less.

The ratio of gas to polyethylene in the dielectric sets the exact Vf.
Manufacturers sometimes adjust that ratio to obtain a given impedance for a
given physical cable size. It's one of the ways impedance is controlled,
when the connectors only take a certain conductor diameter and cable.

73 Tom