  Dynamical antiferromagnets pump spins efficiently into adjacent conductors as
ferromagnets. The high antiferromagnetic resonance frequencies represent a
challenge for experimental detection, but magnetic fields can reduce these
resonance frequencies. We compute the inverse spin Hall voltages resulting from
dynamical spin excitations as a function of a magnetic field along the easy
axis and the polarization of the driving AC magnetic field perpendicular to the
easy axis. We consider the insulating antiferromagnets MnF$_2$, FeF$_2$, and
NiO. Near the spin-flop transition, there is a significant enhancement of the
DC spin pumping and inverse spin Hall voltage for the uniaxial antiferromagnets
MnF$_2$ and FeF$_2$. In the biaxial NiO, the voltages are much weaker, and
there is no spin-flop enhancement of the DC component.
