Radio receiver with two tuners and a switch for verifying reception quality at an alternative frequency

摘要

A radio receiver having a circuit arrangement for checking the quality of reception at an alternative frequency to a received transmit frequency. The radio receiver has two tuners for converting the received signals to two different intermediate frequencies and a switch, which is preferably switched by a microprocessor, for optionally forwarding signals from signal processing branches that are each connected to one of the tuners. This reduces the cost of implementing the second receiver, at the same time reducing the barely noticeable impairment of the set program when checking the quality of reception at the alternate frequency. The latter is achieved by positioning the switch upstream from an analog-digital converter, operating at a sampling frequency, of an intermediate frequency stage. The different intermediate frequencies are selected so that they both meet the following condition:; $PTEXTHILITALICPDATf/PDAT/ITALIC/HILHILSBPDAT0/PDAT/SB/HILPDAT\=(n\+R)/PDATHILITALICPDATf/PDAT/ITALIC/HILHILSBPDATa/PDAT/SB/HIL/PTEXT$ ;where n is a natural number, and 0≦R≦1 applies. An intermediate frequency filter, a demodulator, possibly a decoder for additional signals, and a test unit for determining signal quality are connected to the analog-digital converter.