| 摘要 |
A pager responsive to broadcasts from two networks consists of; a radio frequency receiver stage consisting of two local oscillators 8, 9, one for each pager network, an antenna 5, amplifier 6, band pass filter 7 and a mixer 11 for mixing signals from one or other local oscillator with signals from the antenna; an intermediate frequency stage; and a control system which electronically switches on and off the local oscillators and which electronically tunes the antenna, amplifier and band pass filter. <IMAGE> |
