  We have previously [Phys. Rev. A 65, 043803 (2002)] analyzed adaptive
measurements for estimating the continuously varying phase of a coherent beam,
and a broadband squeezed beam. A real squeezed beam must have finite photon
flux N and hence can be significantly squeezed only over a limited frequency
range. In this paper we analyze adaptive phase measurements of this type for a
realistic model of a squeezed beam. We show that, provided it is possible to
suitably choose the parameters of the beam, a mean-square phase uncertainty
scaling as (N/kappa)^{-5/8} is possible, where kappa is the linewidth of the
beam resulting from the fluctuating phase. This is an improvement over the
(N/kappa)^{-1/2} scaling found previously for coherent beams. In the
experimentally realistic case where there is a limit on the maximum squeezing
possible, the variance will be reduced below that for coherent beams, though
the scaling is unchanged.
