Hello Alan,

Using Dave G3YMCs figures for dynamic resistance and and assuming it

linearly with increasing loop periphery, I worked out the efficency of

loop sizes.

Assuming that dynamic resistance = radiation resistance and periphery =
circumreference :

The radiation resistance of a loop is proportional to the square of the
loop area. So doubling the circumreference (keeping the shape unchanged)
will quadruple the loop area and thus it will increase the radiation
resistance by a factor of 16.
But at the same time it will double the 'copper-loss' so the efficiency of
the loop will increase 8 times (assuming the 'copper-loss' is dominant).

73, Rik  ON7YD