Importance

Loading Importance Indicators...

Abstract

There is disclosed a scanning radio receiver intended for use on the frequencies assigned to the Public Safety Radio Services and which is also operable for reception in the aircraft band from 118 MHz to 136 MHz. The receiver is operated under the control of a microcomputer which includes a ROM and a processor. The processor outputs a frequency code to a frequency synthesizer which controls the frequency of signals received by the receiver and at the same time, the processor synchronizes a timer which determines the amount of time allowed for the synthesizer to lock on a frequency before a signal present line is tested. While waiting for the synthesizer to lock, the system finds the next code which it will output. The time left after finding the next code is devoted to refreshing a display. When the synthesizer lock time has elapsed, the timer generates an interrupt signal which is transmitted to the processor and if the system is in a scanning mode and no signal is received, a new code is immediately output to the synthesizer.

Loading the Abstract Image...

First Claim