TH6547B - An FM signal relay circuit for television tuners that can receive both television and FM signals through the same tuner. - Google Patents

Abstract

television receiver Includes a single tuner for tuning TV channels. and the FM station used to spread out The tuner is made to run at a given gain. which is tuned in the receiving mode of the FM tuner system acts as a conversion sector. Part one of the FM receiver with exponential change, where the mixer of the integrated circuit of the FM radio system acts as the second sector converter Such arrangements operate at the first IF frequencies specific to and not specific to the FM receiver. It is used to automatically receive National Broadcasting Service (NWS) broadcasts at one of the seven NWS preset frequencies that operate in the listener's area. The receiver will display on the screen the number of channels of the FM system being tuned.

Claims (7)

1. The FM signal trap circuit consists of an input terminal for receiving the television radio frequency signal and the FM radio signal spreading. The first tuning circuit includes the first inductor, the first resistor, and the first capacitor. One such inductor The first resistor and the first capacitor They are connected in parallel with each other, and one end of the parallel interface is connected to the input terminals. The parallel connection of the first tuning circuit has a second end. The second tuning circuit includes the second inductor and the second capacitor. One such inductor And the second such capacitor is connected in parallel, and the first end of the parallel connection is connected to the aforementioned second end of the second tuning circuit. With a second tip The third tuning circuit includes the third inductor, the second resistor. And the third capacitor The third inductor, the second resistor, and the third capacitor are connected as a derivative. And one end of the serial interface is connected to it. The serial connection of the third such circuit has a second end connected to the position of the reference potential and the output terminal to the said second end of the second tuning circuit. For producing signal output And connected to the circuit that responds to the FM radio signal that is used to spread and the radio frequency of the said television radio Where the FM system tracks the signal There is a relatively flat non-accepting region of the broadband FM radio used to spread. For through the FM radio signal that is used to spread at the reduced amplitude and where the circuit traps the said FM system. This will result in a uniform fading of the FM broadcasting signal for most of the FM radio bands used to spread it. 2.Track the FM signal of claim 1, where the frequency band of the broadcast FM radio includes the highest and lowest frequency ranges. And the first tuning circuit Will be tuned to a frequency with which all frequency response is consistent. The second tuned circuit is tuned to shield television signals adjacent to the highest frequency of the FM radio frequency band used to spread. And the third tuning circuit It is tuned to shield the TV signal at the channel adjacent to the lowest frequency of the FM radio frequency broadcasting system. 3.Track the FM system signal of claim 2, where the first tuning circuit is tuned at approximately 97.5 MHz. The second such tuning circuit is tuned at approximately 104.0 MHz. And the third such tuning circuit is tuned at approximately 90.5 MHz. 4. TV receiver with a tuner For tuning a television's radio frequency (RF) band and a radio frequency (RF) frequency band, the FM system broadcasting such a television receiver consists of an input terminal for the RF signal of the television and the signal. RF FM system used to spread it. Tuning circuit for reducing the amplitude of the said FM system RF signal and for passing the amplitude-reduced RF signal to the output. The tuner has an inputs connected to the said input terminals and the tuners have inputs connected to the said outputs of the tuners for and responding to the RF signal of the TV. And the FM system RF signal that used to spread that reduces the amplitude then The tuning circuit has a relatively flat region that does not accept most of the frequency bands of the FM systems used for propagation. For the uniform fading of the RF signal, the FM broadcasting system is used for almost all of the radio bands such broadcast FM systems are used. 5. TV receiver of Clause 4, where the tuning circuit is, the FM system trap circuit includes The first tuning circuit includes the first inductor. The first resistor and the first capacitor One such inductor The first resistor and the first capacitor They are connected in parallel with each other, and one end of the parallel interface is connected to the input terminals. The parallel connection of the first tuning circuit has a second end. The second tuning circuit includes the second inductor and the second inductor, the second such inductor. And the aforementioned second capacitor are connected in parallel and have the first end of the parallel connection. Connected at the junction to the second such end of the first tuning circuit. Such a parallel connection Has a second tip The third tuning circuit includes a third inductor, a second resistor, and a third capacitor. The third inductor, the second resistor, and the third capacitor are connected in series to each other. And there is one end of the serial interface that is connected to it. The serial connection of the third tuning circuit The second end is connected to the position of the reference potential and the output terminal is connected to the said second end of the second tuning circuit for producing the output signal. 6. Television receiver of claim 5, where the frequency band of the FM radio used to spread includes the highest and lowest frequency ranges. And the first such tuning circuit will be tuned to a frequency that all the frequencies meet are consistent. The second such tuning circuit is tuned. To provide protection for television signals on channels adjacent to the maximum frequency of the radio frequency bands used by the FM system to spread such And a third such tuning circuit is tuned to provide protection against television signals at the channels adjacent to the lowest frequency bands of the FM systems used to spread. 7. TV receiver of claim 6, where the first such tuning circuit is tuned at approximately 97.5 MHz, such a second tuning circuit is tuned at approximately 104.0 MHz. Sketch And the third such tuning circuit is tuned at approximately 90.5 MHz.