TH12684A - First mid-frequency filter with trap circuit The intermediate frequency is half a second circuit for use in the FM radio system in the television set. - Google Patents

Abstract

Television receiver Including a single tuner for tuning television channels And FM station used to spread The tuner is activated at the specified gain. Which is adjusted in the modulation of the FM tuner system acts as a conversion sector Part one of the FM receiver That has been changed exponentially, where the mixer of the integrated circuit of the FM radio system. Serves as the second sector The arrangement will operate at the first specific IF frequency and not the FM receiver only. Automatically receives National Broadcasting Service (NWS) broadcasts at one of the seven predefined frequencies of the NWS operating in the audience area. The receiver will display on the screen the number of tuned FM system channels.

Claims (5)

1. A television receiver consists of a tuner path. For working in the first mod To receive RF signals Of the TV tuner way Signal will be selected Specific television RF from a certain number of TV RF signals in response to control signals. Control methods for producing such control signals To make that way, the tuner chooses that specific RF signal. The tuner trajectory also works in the second mod, the first frequency converter. For radio receivers with FM systems. Use spreads with exponential conversion. And to convert the signal of a specific FM system Is the first intermediate frequency The second frequency converter of the FM radio receiver. That spread out with such multiplication The second frequency converter sector. Will receive the signal at the aforementioned intermediate frequency And converts the signal at the second intermediate frequency and the path for the sound signal demodulation from the said signal at the aforementioned second medium frequency and where the first mid frequency is 43.3 MHz It also contains a tuning circuit for a given frequency. Including inductance The first capacitor and the second capacitor are classified as a diatonic filter. And including the third capacitor Is in parallel with the said inductor. Tuning circuit for the specified frequency Will be created as a flat-pass filter. For the first such intermediate frequency And half of the middle frequency trap circuit For the aforementioned second intermediate frequency The specified frequency tuning circuit receives the signal from the first frequency inverting sector, filtering the signal receiving the first frequency converter. And supplying the filtered signal to the second frequency converter sector 2. The TV receiver of claim 1, where the second intermediate frequency will be 10.7 MHz and the half of the mid-frequency trap is tuned to the attenuated signal at 48.65 MHz. 3. TV receiver consists of The tuner way to work in the first mod. To receive RF signals Of the TV tuner way Signal will be selected A specific television RF from the TV's RF signal responds to the control signal. Control paths for producing control signals To make the way, the Junner selects that specific RF signal. The tuner trajectory also operates in the second mod, as the first frequency converter, for the dual-converted FM radio receiver. To convert the FM radio signal used to spread into the first medium frequency. The second frequency converter of the FM radio receiver. The second frequency converter receives the filtered signal at the first intermediate frequency. And converts it into a second intermediate frequency and the path for the demodulation of the audio signal from it at that second center frequency and where the receiver Also contains A rated frequency tuning circuit that produces both a band-pass filter. For the first such intermediate frequency And creates a half-intermediate-frequency loop for the second intermediate frequency, the specified frequency tuner receives the signal from the said first frequency converter Filtering obtained from the first frequency converter. And supply the filtered signal to the second frequency converter sector 4. TV receiver of claim 3, where the first intermediate frequency The above will be 43.3 MHz and the aforementioned tuning circuit. Including the inductor, the first capacitor and the second capacitor. Is classified as a pi-type filter And including the third capacitor in parallel with the said inductor 5. TV receiver of claim 4, where the second intermediate frequency will be 10.7 kHz and the half of the center frequency trap circuit. Tuned to a 48.65 MHz attenuation signal