This was a live-action SF show I saw during my childhood in the early 1980s, so it could be a repeat from the 1970s. It was on UK TV, but that doesn't necessarily mean its a UK production.
The (unfortunately few) points I can remember are:
Radio telescopes were a central plot point, including several shots of large Jodrell Bank style ones
The aliens were never seen, but interacted through people by giving them powers and influencing their behaviour
People were given special powers such as telekinesis, and they could combine powers with another person by joining hands above their heads
In at least one episode, much was made of someone making a model which represented the aliens' influence - this model consisted of a number of spheres and pyramids on a flat base. This model was destroyed by another character when they found out this person was under the alien influence.