| 摘要 |
PURPOSE:To easily correct the change of a signal level caused by the change of the frequency of a shift signal, and to stabilize the signal level of an output signal. CONSTITUTION:Shift signal oscillators 11a and 11b generate the shift signal. A mixer 13 mixes an input signal with one shift signal selected by a changeover switch 12. The input signal mixed with the shift signal is supplied through a band pass filter 14 to an attenuator 15. An upper address selection switch 17 is interlocked with the changeover switch 12, and a storage area corresponding to one of the shift signal oscillators 11a and 11b is selected. A memory 16 supplies attenuating amount set data stored in a storage place designated by a digital switch 18 in the storage area selected by the upper address election switch 17 through a D/A converter 19 to the attenuator 15. The attenuator adjusts the level of the output signal according to the attenuating amount set data from the memory. |
