RADIO:

In May 1945, the Soviets are the first Allies to enter Berlin. They immediately take over the city's only surviving radio transmitter. The transmitter is in the British Sector, but the Soviets refuse to allow other Allies to use it.

In November 1945, without a radio transmitter, American Allies start DIAS or Drahtfunk. Telephone wires carry the signal to special home receivers.