  We discuss the effective donor/acceptor coupling for a bridged electron
transfer system with a site-diagonal disorder of bridge energies. The average
spectral properties of the system are discussed by using the Wegner model
(Anderson's type tight-binding Hamiltonian (TBH))for the electronic part of the
problem. Spectral properties of the system are discussed using the concept of
the functional inverse of the resolvent (``Blue's function'', introduced by
Zee) for various limits of noise versus site-site coupling ratio.
