Moiseev М. А. RussiaNizhny Novgorod Institute of Applied Physics of the Russian Academy of Sciences, ul. Ul'yanova, 46, Nizhny Novgorod , 603950, Russia moiseev@appl.sci-nnov.ru Author's articles ZONES OF STABLE SINGLE-MODE GENERATION IN OVERMODED GYROTRONS THE INVESTIGATION OF SUBTERAHERTZ GYROTRON FOR DNP SPECTROSCOPY IN THE IAP RAS