  The SZE-21cm has been proposed as an alternative probe for the Dark Ages (DA)
and the Epoch of Reionization (EoR). The effect is produced when photons of the
21cm background are inverse Compton (up-)scattered by electrons residing in hot
plasma of cosmic structures and can be studied through differential
observations of the large-scale structure, towards and away a region of the
radio sky containing the cosmic structure of interest. This work makes use of
the 21cmFAST code to simulate low frequency radio observations of a galaxy
cluster from which we then extract the SZE-21cm signal. We further explore uses
of the differential technique to radio observations of active radio galaxies
using radio observations from the MWA GLEAM survey. The differential techniques
this work studies enable us to extract the SZE-21cm signal from simulated
galaxy cluster observations, which can then be used to obtain the global
features of the 21cm signal during the DA and EoR. The technique shows further
benefits in source extraction and characterisation, and feature enhancement in
radio observations particularly for low-surface brightness and extended radio
sources.
