  We present high-sensitivity, wide-band observations (704 to 4032 MHz) of the
young to middle-aged radio pulsar J1452-6036, taken at multiple epochs before
and, serendipitously, shortly after a glitch occurred on 2019 April 27. We
obtained the data using the new ultra-wide-bandwidth low-frequency (UWL)
receiver at the Parkes radio telescope, and we used Markov Chain Monte Carlo
techniques to estimate the glitch parameters robustly. The data from our third
observing session began 3 h after the best-fitting glitch epoch, which we
constrained to within 4 min. The glitch was of intermediate size, with a
fractional change in spin frequency of $270.52(3) \times 10^{-9}$. We measured
no significant change in spin-down rate and found no evidence for
rapidly-decaying glitch components. We systematically investigated whether the
glitch affected any radiative parameters of the pulsar and found that its
spectral index, spectral shape, polarisation fractions, and rotation measure
stayed constant within the uncertainties across the glitch epoch. However, its
pulse-averaged flux density increased significantly by about 10 per cent in the
post-glitch epoch and decayed slightly before our fourth observation a day
later. We show that the increase was unlikely caused by calibration issues.
While we cannot exclude that it was due to refractive interstellar
scintillation, it is hard to reconcile with refractive effects. The chance
coincidence probability of the flux density increase and the glitch event is
low. Finally, we present the evolution of the pulsar's pulse profile across the
band. The morphology of its polarimetric pulse profile stayed unaffected to a
precision of better than 2 per cent.
