A Gravitational Wave Transmitter Author: Gregory Benford, Department of Physics & Astronomy, UC Irvine Description: We consider how an advanced civilization might build a radiator to send gravitational waves signals by using small black holes. Micro black holes on the scale of centimeters but with masses of asteroids to planets aremanipulated with a super advanced instrumentality, possibly with very large electromagnetic fields. The machine envisioned emits gravitational waves in the GHz frequency range. If the source to receiver distance is a characteristic length in the galaxy, up to 10000 light years, the masses involved are at least planetary in magnitude. To provide the energy for this system we posit a very advanced civilization that has a Kerr black hole at its disposal and can extract energy by way of super-radiance. Back ground gravitational radiation sets a limit on the dimensionless amplitude that can be measured at interstellar distance using a LIGO like detector.