Two versions of powerful pulsed gyroklystrons were elaborated for radarsystems with specific requirements for their power, gain and bandwidth. Thefirst tube had two cavities in the TE 021 .mode. It yields 750 kW of outputpower with efficiency 24%9 gain 20 dB, and bandwidth 0,6% . The secondmu%ticavity gyroklystrmn in the TE 011 mode yields output power between 150and 250 kW with efficiency up to 48%, gain up to 40 db and bandwidth up to195% . The pulse width of the tubes is 100 /us.