All receivers add random noise to the signals they pick up.
This noise hides many weaker source of radio emission - just the sources radio astronomers want to look at. By observing the same sky position for longer some of the noise cancels itself out, because it is random. But if the receivers could be made less noisy instead, say by a factor of two, the necessary observing time would be shortened by a factor of four. So it is always worth being at the leading edge of radio receiver technology. At Jodrell Bank we have a team of dedicated radio engineers who work to a goal of more and more sensitive receivers.