  We present multi-frequency polarization observations of the diffuse radio
synchrotron background modulated by Faraday rotation. No total intensity is
observed, indicating that total intensity does not vary on scales below
approximately a degree. However, polarized intensity and polarization angle
show abundant small-scale structure due to Faraday rotation in the warm ionized
disk on small scales. The distribution of Rotation Measures enables us to
estimate structure in magnetic field, weighted with electron density, in the
warm ionized disk.
