All kinds of primeval perturbations of the Universe should result in fluctuations of the microwave background radio emission. Here we report our latest upper limits to these fluctuations on scales 5′ to 3°. Using the new 600-m Soviet Radio Telescope we obtained a mean temperature profile of the region from 08h to 15h in R.A., centred at the declination of the Coma Cluster. 20 good records of this region were used in the final reduction of the data. After “normalization” of these data by filtering out low-frequency atmospheric noise and “bursts” which exceed the 4σ level we calculated an upper limit to the fluctuations of the microwave background radiation.