Ian, G3SEK wrote:
"Now tell us about radiation from the line."

Reg`s problem has a line as long as it is wide. That would make a very
small square loop if I read right. The same current flows in all 4
sides.

According to Arnold King:
Beta is a factor = 2 pi/Lambda
Say Lambda=1, then Beta=2pi

Radiation resistance= 20 times Beta to the 4th times A squared

Say the sides of the tiny square loop are 0.01Lambda, then A, the loop`s
enclosed area is
0.0001

Radiation resistance =
20 (1555) (10 tp -8th)

=31100 (10 to -8th)
=0.00031 ohm

Radiated power = Isquared (radiation resistance)
Radiated power = negligible

Best regards, Richard Harrison, KB5WZI