Abstract: A navigational unit having a time-shared mode of operation for handling a plurality of different navigational signals is provided wherein IF components within the unit may have a dual dedication, i.e., used in common for handling all signals while normally present separate front end components and navigational display components may be dedicated exclusively to each separate signal, a central timing and control component coordinating the total operation.

Abstract: In an information receiving apparatus having a time-shared mode of operation for simultaneously receiving a plurality of information carrying signals, at least one signal of which includes an identification tone superimposed thereupon, a tone reconstitution scheme for providing a continuous tone from a received tone signal which contains absences of tone signal due to the time-shared partial duty dedication of the receiver to that signal and its superimposed tone.

Abstract: A general aviation navigational receiver is provided with a digital channel selection wherein a channel selection knob on the aircraft control board may be operated to control the functioning of a digitally implemented frequency synthesizer which in turn controls the operation of a voltage controlled oscillator for providing frequency signals to an RF mixer of the unit, the frequency synthesizer being programmed for both possible VOR/LOC and GS channel frequencies wherein switching between frequencies is accomplished in synchronism with the basic clock within the synthesizer greatly reducing transient changeover time.