On 10 May, 12:58, Cecil Moore wrote:
art wrote:
I am aware that the impedance of a particular
atmosphere is 377 ohms but that is certainly not a ratio.

From:http://whatis.techtarget.com/definit...845268,00.html

Mathematically, the Zo of free space is equal to the square root of the
ratio of the permeability of free space (µo) in henrys per meter (H/m)
to the permittivity of free space (o) in farads per meter (F/m):

Zo = (µo/o)1/2

= [(1.257 x 10-6 H/m)/(8.85 x 10-12 F/m)]1/2

= 377 ohms (approximately)

The exact value of the Zo of free space is 120 pi ohms, where pi is the
ratio of the circumference of a circle to its diameter.
--
73, Cecil, w5dxp.com

O.k. Cecil I will for the moment embrace that a ratio must have a unit
of measurement which puts me in line with all the amateurs of this
newsgroup (see I am flexible). I will also change from particles now,
to electrons and now to protons as requested ( see I am flexible
again)
For my interest, what is the unit that must be used for the front to
back ratio of a directive antenna?
Regards
Art