Development of the first Soviet three-coordinate L-band pulsed radar in Kharkov before WWII

The subject of this paper is the complicated, sometimes dramatic, and never-published events around the development of the L-band magnetrons and pulsed radar in Kharkov, Ukraine (then the USSR), in the 1920-30s. Magnetron studies were started at Kharkov State University by Prof. Abram Slutskin. By the end of the decade, they reached the world's highest level in terms of achieved output power and frequency. This work was continued and greatly extended in next decade, when the Ukrainian Institute of Physics and Technology was established, and Slutskin obtained his second job there as a head of the Laboratory of Electromagnetic Oscillations. Based on the successful development of sources, in 1935, he started work on developing a three-coordinate radar. At that time, it was far from clear that the L band and the pulsed method would be more promising. Two-antenna and single-antenna radars were designed, fabricated, and tested, with all-metal and wire-grid three-meter parabolic reflectors. The war disrupted the plans of the radar team, which had to move the laboratory to central Asia. The radar that was developed was not put into serial production; however, many associated ideas and innovations were well ahead of the contemporary level of technology. The paper also throws some light on how hard it was for scientists and engineers to work in the Orwellian environment of the pre-war USSR.