[en] The magnicon belongs to the class of high power RF sources, where a modulation is provided by the beam circular deflection and it is an advanced version of a gyrocon. The first magnicon has been built and tested in Novosibirsk in the middle of the 80's. The power of 2.6 MW has been obtained for the frequency 91.5 MHz and pulse duration 30 mcsec. The electron efficiency has been 85%. Good results obtained during investigations show that the magnicon can be an adequate RF source for the next generation of accelerators, especially for future linear colliders and accelerators for transmutation of nuclear waste. The magnicon conception described in the present paper allows to increase significantly the beam perveance, compared with the first magnicon, and to achieve the pulse power of tens and hundreds megawatts at the beam voltage not greater than 400-600 kV. The device is an amplifer working in frequency doubling mode and is a prototype of a RF source for linear colliders with high acceleration gradient. The magnicon is designed for an output power of 50 MW, an operating frequency of 7 GHz and a pulse duration of 2 mcsec