CORDLESS TELEPHONE SET

PURPOSE:To quicken the lock time when a channel transfer range is large, to reduce resident FM and to improve the S/N by providing a changeover circuit to the telephone set and selecting a constant of a loop filter in response to the channel transfer range. CONSTITUTION:When a channel transfer width of a reception PLL frequency synthesizer 5 and a transmission PLL frequency synthesizer 6 are small or the synthesizers are in lock state at channel changeover, a control circuit 4 discriminates it and loop filter changeover circuits 8,9 increase a time constant of low pass filters 51,61. When the channel transfer width is large, the control circuit 4 discriminates it and the loop filter changeover circuits 8,9 decrease the time constant of low pass filters 51,61. Thus, the lock time when the channel transfer range is large is quickened and when the channel transfer range is small or in the case of the lock state, the resident FM is reduced and the S/N is improved.