| 摘要 |
<p>1. Circuit arrangement for determining the figure of merit of reception at the antenna of an FM receiver, in which arrangement the FM demodulator (4) of the receiver is followed by a selective filter (7) having a relatively narrow bandwidth above the stereo multiplex signal within the IF bandwidth, the output of which filter is connected to the input of a level comparison stage (10), and the output signal of the level comparison stage (10), as a weighted noise signal, switches a control circuit (2), characterised in that the output of the selective filter (7) is connected via an integrating stage to the input of the level comparison stage (10), in that the control circuit (2) comprises a station-finding circuit or an antenna diversity circuit, and in that in the signal path of the weighted noise signal a gain control (100) is provided which is electronically controllable in dependence on the RF input level and the control characteristic of which is designed in such a manner that the value of the measured quantity of the figure of merit of reception, which value can be obtained from the level comparison stage (10), decreases with decreasing field strength below a predetermined low RF input level (P).</p> |
