Work on magnetron oscillations by Czech physicist August ŽáČek, his students and colleagues

This article deals with the history of magnetron oscillations research in the former Czechoslovakia in the 1920s – 1950s, primarily with the work of Czech physicist August ŽáČek (1886–1961), his students and colleagues at Charles University in Prague, and with the work of Czech physicist Josef Sahánek (1896–1942) from Masaryk University in Brno. The question about magnetron research during WWII and in the first post-war decade is open up.