Control element for simplex HF to VHF/UHF cross-band system with transmission breakthrough

摘要

#$%^&*AU2007203522B220110908.pdf#####ABSTRACT The device and method disclosed deals with the operation of a cross-band simplex radio frequency communications system. In a system having a first band receiver on a 5 first radio frequency band for receiving and demodulating a first received signal, and a second band transmitter using a second radio frequency band to modulate and transmit the demodulated first received signal so as to communicate audio and signaling received by the receiver in one band to the transmitter of another band when in a cross band mode. There is also at least a second band receiver using the second 0 radio frequency band typically associated with the second frequency band transmitter for receiving signals containing audio and signaling which is to be communicated to a first band transmitter so as to reply to the signal received on the first band receiver. A method of the invention disclosed includes the steps of: detecting the occurrence of a predetermined condition associated with the first received signal in the first band .5 receiver; and replacing transmission of the demodulated signal received on the first band receiver with a breakthrough signal for a first predetermined time; ceasing transmission from the second band transmitter; and receiving on the second band receiver for a second predetermined time and determining if a signal is received on the second band receiver and if so allowing remote operation of the first band receiver !0 of the single frequency simplex communications system.2/4 D0 CY e .20 00 C) LAJ 0 LA c 0 _lie N ~ ~ ~ -04i0)LO (D~ LO (DA~OVi CHf I4H