"Owen Duffy"
Can anyone point me to information on calculating the effective
resistance,
including proximity effect, of conductors in a two wire open transmission
_______

Edmund Laport's RADIO ANTENNA ENGINERING has a good treatment of open wire
lines, including a chart on page 398 showing the Zo of balanced,
two-conductor line as functions of wire OD and c-c spacing. The text says
the plot includes proximity effect and non-uniform peripheral charge
distribution. The chart shows a proximity effect only for low ratios of
conductor spacing/OD (below about 4). I could scan it and send it to you if
you wish.

Laport also shows the general equation as:

Zo = 276 log [2*h*a / p*SQRT(4*h^2 +a^2)]

where

h = height above ground
a =spatial dimension in the line cross-section
p = wire radius

RF