We request observation time with the Parkes telescope to investigate the characteristics of four "spider redback" millisecond pulsars (MSPs): PSRs J0838-2827, J0955-3947, J1910-5320 and J2333-5526. Distinguished by their remarkably compact binary orbits, these spider redback MSPs have an orbital period of less than a day and harbor low-mass companions (0.1-0.9 solar mass). The majority of spider MSPs exhibit frequency-dependent eclipses with linear depolarization observed near eclipses. Using the wide bandwidth of the Parkes UWL telescope (700-4000 MHz), we aim to investigate variations in the duration of eclipses within these systems across different frequencies, while also examining the fundamental eclipse mechanism. Our proposal aims to investigate these spider MSPs, using the wide bandwidth of Parkes UWL, specifically by modeling eclipse phase spectra in the optically thick-to-thin transitioning regime (optical depth nearly 1). Additionally, a polarization study using the UWL receiver in full polar mode will help constrain magnetic field strength variation within the eclipse region. This includes probing changes in Dispersion Measure (DM) and Rotation Measure (RM) across the pulsar's orbit, offering crucial insights into the system's specific eclipse mechanism and the presence of a significant magnetic field in the eclipse medium compared to non-eclipsing orbital phase. Therefore, we request a total of 20 hours of observing time including setup, and calibration for the investigation of the eclipse mechanisms, polarization, profile evolution, and spectra in these spider MSPs.
