The amplitude of the gravitational de Broglie waves

We calculate the amplitude of the de Broglie gravitational waves using the standard Einstein General Relativity. We find that these waves disappear in the limit $\hbar \to 0$ and when their source has a large mass and volume. From the experimental point of view, the knowledge of the amplitude allows to estimate the magnitude of the effect of the wave on a sphere of test particles. We propose also to measure a very special shift angle that does not change with time.