KOPPLINGSANORDNING FOR DIGITAL FREKVENSINDIKERING I EN RUNDRADIOAPPARAT

The wideband amplifier is common for oscillations of the AM and FM oscillator, and is followed by a frequency divider with several stages, whose division ratio depends on whether the receiver operates in the AM or FM range. At least one division stage is a decimal counter (1) with two resetting inputs (5, 6) by which it can be set to the figure nine. Resetting input (5) is operative only when a certain logic potential is applied to the resetting input (6). The decimal counter (1) counts trailing edges of rectangular pulses applied to it from the wideband amplifier (8). Leading edges of rectangular pulses are applied to the resetting input (5) through a differentiating circuit (7, 9), while an 'O' or '1' potential can be applied to the input (6) by the range switch through a control wire, so that the counter (1) division ratio is changed from 1:10 to 1:1.