The transmitter may be operated with a paralleling unit PU 1). The PU delivers a control voltage which influences the compensation voltage in the AF stage and thus the duty factor of the PDM signal. Furthermore, the indication "PDM Blocking" is also passed to the PU. The connection to a PU is at X 26 on the pc board of the AF stage. The AF stage is accessible after opening the control panel door.

AF каскад = каскад звуковой частоты

В общем, речь о цифровом передатчике.

Заранее спасибо