  Preliminary results from the MILC collaboration for $f_B$, $f_{B_s}$, $f_D$,
$f_{D_s}$ and their ratios are presented. We compute in the quenched
approximation at $\beta=6.3$, 6.0 and 5.7 with Wilson light quarks and static
and Wilson heavy quarks. We attempt to quantify systematic errors due to finite
volume, finite lattice spacing, large $am$, and fitting and extrapolation
uncertainties. The hopping parameter approach of Henty and Kenway is used to
treat the heavy quarks; the sources are Coulomb gauge gaussians.
