In the present investigation, radial diffusion of equatorially trapped electrons in the magnetospheres of Jupiter and Rotating Radio Transients (RRATs) are examined and compared. It is assumed that electrons lose energy through synchrotron radiation and the wave-particle interaction. The phase space density of the electrons, which go through gradB drift in Jupiter's and RRATs magnetospheres and thus resonate with the plasma waves, changes and this change predicted by the model seems to be consistent with the Pioneer 10 and Pioneer 11 data for Jupiter's case and a similar result obtained for RRATs.