Plain and simple. DON'T!
Mounting anything to a spin stabilized satellite dish will cause it to be out of balance. It may work for a while, but will eventually cause all sorts of problems.

Trust me on this one.

Spin motion establishes a direction for the satellite to point to and stabilizes the satellite.

projectiles can be fin or spin stabilized

Circular polarization characteristics of a helical antenna help offset the effects of spin modulation from satellites in motion, that is, the tendency for satellites to spin causing the position of their antennae to change rapidly in accordance with the spin, causing a fluctuation in the signal as received by a fixed signal on earth. Circular polarization of the earth fixed antenna reduces the fluctuating effects of the satellite's spin on the recived signal.

Because the moon doesn't spin on its axis's [doesn't have one] it is just a satellite around earth.