Low noise radio receivers on Torun 32m antenna

Obliged to keep the attractiveness of the radio telescope to it's users, one need to improve the sensitivity of receivers all possible ways. Reducing receiver noise by applying newest low noise amplifiers, reducing ambient temperature of the cryogenic amplifiers by improving isolation in the dewar, using wider frequency bands, using high dynamic range intermediate frequency amplifiers and other means for frequency bands full of annoying interferences - all these treatments belong to the art of making the best receivers. Radio receivers need to be ready to be used with many back-ends, like VLBI terminals, spectrometers, pulsar machine, polarimeters, so they need to have many additional functionalities built-in, like switchable stable noise sources, phase calibration sources, switchable 0/180 degrees local oscillator signals and more. Review of the Torun 32 m antenna receivers will discuss the above goals in detail.