Tested with the reset Tu-16. Rated power of the bomb was about 3 megatons, but during the test reduced by about half, to 1.6 Mt.
Observers who were 35 kilometers from the epicenter, in special glasses, lying on the ground surface at the time of the flash felt a strong flow of heat, but at the approach of the shock wave - two-time strong and shrill sound, resembling a lightning discharge