Facsimile and static presentation processing – Facsimile – Recording apparatus
Patent
1981-04-10
1983-05-31
Cardillo, Jr., Raymond F.
Facsimile and static presentation processing
Facsimile
Recording apparatus
358186, 358188, 358342, 360 331, H04N 576, H04N 540, H04N 521
Patent
active
043863779
ABSTRACT:
An interface circuit for selectively generating TV RF signals on one of two adjacent TV channels is designed with two independent RF oscillator-modulator circuits. The respective double sideband modulated signals generated by the RF modulators are respectively passed through separate frequency rejection filters designed to attenuate the lower sound sideband of each of the modulated signals. The resultant signals are applied to a common bandpass filter via an isolation network. The pass band of the bandpass filter encompasses substantially the combination of the pass bands of the broadcast TV channels corresponding to the RF signals generated. Consequently the lower frequency RF modulated signal is similar to a conventional vestigal sideband TV signal and the higher frequency RF modulated signal is a double sideband signal minus the lower sound sideband. The isolation network provides electrical connection between the rejection filters and the bandpass filter but establishes a relatively constant impedance at the respective filter output and input terminals irrespective of changes in the filter impedances so that the filters may be tuned to the desired resonances without interaction between respective filter circuits.
REFERENCES:
patent: 3775554 (1973-11-01), Hjortzberg
patent: 3775555 (1973-11-01), Carlson
patent: 4213152 (1980-07-01), Kakinuma
patent: 4215372 (1980-07-01), Suzuki
Video Cassette Recorder Tech Manual (RCA) Models VCT 201 and VCT 400, pp. 3-14 (RF converter).
National Semiconductor Linear Databook (1978), "LM1889 TV Video Modulator," pp. 10-155 to 10-159.
Cardillo, Jr. Raymond F.
Herrmann E. P.
RCA Corporation
Tripoli J. S.
Whitacre E. M.
LandOfFree
TV Interface RF modulation circuitry does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with TV Interface RF modulation circuitry, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and TV Interface RF modulation circuitry will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2247968