Television – Receiver circuitry – Demodulator
Patent
1993-01-29
1995-06-27
Groody, James J.
Television
Receiver circuitry
Demodulator
348738, 348724, 329337, 332136, H04N 540, H04N 5455
Patent
active
054284040
ABSTRACT:
An apparatus and method for demodulating and remodulating a transmitted signal prior to presentation to a television receiver, the transmitted signal comprising a video signal, a first channel signal, and a second channel signal, wherein one of the two channel signals is selected, demodulated and remodulated with the video signal prior to presentation to the television receiver. The apparatus allows the viewer of a television receiver which accepts a single channel signal to select between one of two alternate channel signals associated with a video broadcast without the need to modify the television receiver. The apparatus is particularly well suited for television broadcasts using a dual carrier transmission format. A novel varactor diode tuning means is used in one embodiment for changing the center frequency of a frequency modulation demodulator. The disclosed apparatus also transparently allows stereo demodulation for television receivers which are capable of such stereo demodulation.
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Excerpts from Report on Television Dual Sound Broadcasting Method (Best Available Copy).
Excerpts from Dual Sound Report, in Korean; Figures provided in English (Best Available Copy).
Excerpts from C. Eilers, TV Multichannel Sound-The BTSC System, IEEE Trans. on Consumer Electronics, February, 1985, vol. CE-31, No. 1, pp. 1-7.
Farmer James O.
Ingram Eric J.
Groody James J.
Lee Michael H.
Scientific-Atlanta, Inc.
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