A huge TV & radio sufficiently reflecting effective telescope can be made orbiting out in space, away from Earth TV & radio broadcasts interference. It greatly helps to be very big and wide, partly since TV & radio wavelengths range from as long as part of your leg to much bigger. If detecting some alien planet's broadcast frequency bands, it would stay aimed to collect more.
By now some large radio effective telescopes have been made or were to be formed down on Earth, including the One-Mile Telescope in U.K., the 500m Aperture Spherical Telescope FAST in China, the Australian Square Kilometre Array Pathfinder ASKAP, a Square Kilometre Array SKA in Australia, New Zealand, South Africa, etc. But much better and easier would be huge ones formed robotically in space from parts robotically made from materials refined on selected asteroids. Then much better than huge radio telescopes made or planned confined to some Earth lands, these could be aimed at any time at any chosen star around our galaxy, and kept tightly aimed around it for hours or days, trying to detect, then save any alien broadcasts from any of its planets.
Being weightless in space out in years-long orbits around Sol, these could be strongly formed many kilometers wide from some suitable reflective metal, formed into good focusing reflector telescopes. Give each a large mass sphere which could be given any wanted direction spin weightless in space, thanks to well controled non-touching frictionless surrounding electromagnetic coils. Then starting such a sphere with some suitable direction spin would cause the huge radio/TV telescope to slowly spin in the opposite direction. Thus changing aiming directions wouldn't require any ion jets. Electricity harvested essentially free from Solar light would energize turning the sphere. Then once it had gotten freshly aimed somewhere newly wanted, halting the sphere spin would halt the reversed spin of the huge radio/TV telescope.
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