Black holes or neutron stars can work as gravity sling also for radio waves (SOS-messages from other stars)

One of the most fascinating ideas of physics is that black holes or some super magnetic objects like neutron stars can work as the gravity or magnetic sling for radio waves and this thing might explain the things like "SOS-calls from another galaxy or star". In this scenario, the super powerful gravity or magnetic field would turn the radio signals back to Earth, and of course, our SETI-telescopes would see that signal.

Or would they? The thing is that the radio telescopes would notice the radio frequency, but actually, we must ask some other questions, if we would want to get answers, and one of them is would SETI-telescope see those radio frequencies, what is used for radio transmissions on Earth before communication satellites. The communication satellites can send the signals back to earth and allow to use more radio frequencies than normal radio communication systems would use.

The frequencies, what is used for radio communication between two radios on earth,  is one common thing, they must snap back from the ionosphere, or we must put the communication satellite between those points. And then we must see, that if we would use those frequencies, what is snapping back from ionosphere for the communication between the ground station and spacecraft, would the communication be very difficult because the radio signals would snap back to earth.

And then we are facing the thing about the SETI-program. The thing is that those radio signals would not even get to space, what is used for telecommunication between two ground stations. Of course, some radio waves can self transfer their frequency when they would give electromagnetic resonance to the oxygen and nitrogen atoms.

In those cases, the electromagnetic radiation would make those atoms resonate, and then they are starting to send the radio and other electromagnetic radiation in the frequency, what is characteristic for every element, and this phenomenon makes the ability to see the chemical components of stars and other materials by using spectroscopy. The communication satellites allow using other radio frequencies than the frequencies, which are snapping from the ionosphere.