  We consider a tachyon field whose Fourier components correspond to spatial
momenta with modulus smaller than the mass parameter. The plane wave solutions
have them a time evolution which is a real exponential. The field is quantized
and the solution of the eigenvalue problem for the Hamiltonian leads to the
evaluation of the vacuum expectation value of products of field operators. The
propagator turns out to be half-advanced and half-retarded. This completes the
proof [4] that the total propagator is the Wheeler Green function [4,7].
