The landlord wants to prohibit installing a satellite dish on the balcony

That's exactly what I think as well, that the rental contract is important. In my family, the satellite dish also had to be removed from the balcony. Moreover, they have cable TV, and the installation of a dish was also prohibited in the rental contract.

My friend had the same problem, but he then came to an agreement with the landlord and his dish was installed where it doesn't bother anyone. Just talk to each other, that can often help.