  The X-ray Pulsar PSR J1811-1925 in the historic supernova remnant G11.2-0.3
has a characteristic age over 10 times the age of the remnant. This likely
implies that its current spin period, 65 ms, is close to its birth spin period.
Alternatively, the pulsar may have an unusually high braking index. We report
here on regular Rossi X-ray Timing Explorer/ Proportional Counting Array
(RXTE/PCA) timing observations of the pulsar that were designed to measure its
braking index. We provide a preliminary phase-coherent timing solution which
includes a significant $\ddot{\nu}$. The braking index we measure is >> 3,
likely a result of conventional timing noise. We also report on a preliminary
analysis of the pulsar's unusually hard spectrum: we determine a photon index
of $\Gamma = 1.78\pm0.74$, for the pulsed component of the spectra, consistent
within the uncertainties with previous ASCA and Chandra observations. The
pulsed emission of PSR J1811-1925 is seen beyond 30 keV, and the pulsations
remain sinusoidal up to and beyond this energy.
