Photoelectric and visual observations of AM Cas

According to statistical informations the orbital period of this cataclysmic binary of Z Camelopardalis type should be in the range between 0^d.10 and 0^d.19. A sole deep minimum was found photoelectrically. It lasted about 40 minutes and had an amplitude of nearly 2 mag in U. For reasons described in detail it can hardly be interpreted as an eclipsing one. Possibly there is no contribution to the light variation of AM Cas from orbital motion.