Cassette recorder

The Cassette recorder (Dads old world receiver) is an audio device from Secret files tunguska in Wladimir Kalenkow's House on Wladimir Kalenkow's Desk.

At first you don't can switch it on, cause Nina says „The aerial ist broken off, a cassette isn't inside. Expect a reassuring regular sounding Roaring i wouldn't hear something.“

Cassette 1
Wladimir Kalenkov: The first and the last at the Car, from the Entrance in the underground a quarter of the holes and finally the guards from my work.

Nina: What? What is this? A Code? Dad, sometimes your really gaga.

Solution
Kassettenrekorder Cassette recorder