  The conductance fluctuations of a metallic wire which is interrupted by a
small tunnel junction has been explored experimentally. In this system, the
bias voltage V, which drops almost completely inside the tunnel barrier, is
used to probe the energy dependence of conductance fluctuations due to disorder
in the wire. We find that the variance of the fluctuations is directly
proportional to V. The experimental data are consistently described by a
theoretical model with two phenomenological parameters: the phase breaking time
at low temperatures and the diffusion coefficient.
