| 摘要 |
PURPOSE:To attain transmission/reception between a master and a slave station through an optional channel by providing a frequency synthesizer to the master and slave stations of a wireless telephone set, a channel selection means to the slave station and a frequency sweep circuit to the master station. CONSTITUTION:When the slave station operates a channel selection means 18, a safety code generated from a code generating circuit 11 modulates a frequency f3 from a frequency synthesizer 9 comprising a PLL and sends the result to the master station in the wireless telephone set comprised of the master station connected to a telephone line and the slave station making transmission/ reception in radio. If crosstalk takes place at the slave station, the means 18 is operated to set a new channel, a signal representing the reduction in the carrier level is impressed to a sweep circuit 31 in the master station, the circuit 31 applies a sweep pulse to a frequency synthesizer 29 to apply frequency sweep. When the signal is tuned to the carrier from the slave station, the safety code from the slave station is detected by a detection circuit 32 and when the code is coincident with a prescribed code, the detected output is fed to the circuit 31 via a delay circuit 33 to stop the sweep. |
