Szczepan Bia³ek wrote:
In the halve of the cycle the both antennas lose mass and in
the next halve gain mass.

Actually, a radiator radiates equally during each
half cycle, i.e. it loses equal mass during each
half cycle.

Hint: think balanced transmission line with its
two equal differential currents. Electrons on the
balanced radiator are accelerated/decelerated
equally in either direction.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com