Review of the RP-1 geological prospecting radiometer, an extremely popular device in the USSR for searching for uranium ores. This is a very rare device today, only a few units are known. The radiometer was produced in 1956 at the Geologorazvedka plant in Leningrad. From the review we will learn how it is designed and how to work with it, and also get acquainted with the literature of the 50-60s dedicated to the radiometer.