We propose and demonstrate a photonic approach to a reconfigurable channelized radio frequency (RF) receiver for instantaneous RF spectrum monitoring and analysis. Our approach relies on the generation of high quality copies of the RF input by wavelength multicasting in a 2- pump self-seeded parametric mixer and the use of off-the-shelf filtering element such as Fabry-Perot etalon and wavelength division demultiplexers. The parametric channelizer scheme trades frequency non-degeneracy of the newly generated copies for ease of filtering design. Self seeding scheme employed to wavelength multicast the original RF signal to a large number of copies enables easy reconfigurability of the device by simple tuning of the three input waves, i.e. seed and pumps. Channelizer operation to up to 15GHz bandwidth and channel spacing of 500MHz is demonstrated. Reconfigurability is verified by tuning the receiver operating bandwidth and channel spacing.