As a part of preparations for setting the ground station for the planned PW-Sat3 student satellite, analysis of the spectrum in the 70cm band was made in Gdynia region by members of the science club. It was found out that very strong radio interference is present in this band. Interference was pinpointed to Voronezh-DM radar installed in about 2013 by the Russian military in the Kaliningrad Oblast. Measurements were made to determine the strength and characteristics of the signals emitted by this radar. The signal level in Gdynia region somewhat depends on propagation, but is always present, making receiving weak satellite signals difficult or impossible. Additionally,
the potential effects of radar on signals received by satellite was analyzed. Evidence of problems in communications, which might originate from Voronezh-DM radar, in this frequency range in previous satellite missions was found and presented. Other Voronezh-DM radars in other parts of the globe are present, and although operating on slightly different frequencies might also influence satellite communication in the 70cm band.