Showing papers in "IEEE Transactions on Broadcasting in 1976"
TL;DR: In this paper, the VHF high-band and low-band cavity-backed radiator antenna described in this paper is part of a development program aimed at meeting the requirements of TV broadcasting.
Abstract: Current interest in circular polarization for TV broadcasting has increased to such proportions that many broadcasters are planning new facilities, anticipating its adoption. The VHF high-band and low-band cavity-backed radiator antenna described in this paper is part of a development program aimed at meeting those requirements.
7 citations
TL;DR: In this paper, two new additions to the turnstile family of antennas are described: a horizontally polarized "turnstile II" antenna and a circularly polarized "Turnstile III" antenna.
Abstract: Two new additions to the turnstile family of antennas are described: 1) a horizontally polarized "turnstile II" antenna and 2) a circularly polarized turnstile antenna. These antennas feature a rotating phase feed based on the original RCA Superturnstile design which, because of its simplicity, electrical characteristics, and versatility, is today the most popular TV broadcast antenna.
6 citations
TL;DR: In this article, multiple-antenna arrays with respect to size, performance characteristics, and cost are discussed with a focus on the use of circularly polarized antennas on candelabra arrays.
Abstract: Multiple-antenna arrays are discussed with respect to size, performance characteristics, and cost. Parameters are given to facilitate optimizing by the broadcaster of multiple-antenna structure size and performance. Use of circularly polarized antennas on candelabra arrays is also discussed.
6 citations
TL;DR: A simple and general analysis for any form of AM-to-PM conversion using derivative form and supposing the video signal to be relatively small is shown, from the analysis, it can be seen how the video- to-video frequency response varies and how much of the lower sideband (LSB), once filtered, will emerge with respect to the amount of PM conversion.
Abstract: Incidental phase modulation caused by AM-to-PM conversion (carner phase shift) of RF amplifier degrades the detected video signal performance. Its effects are known to be different for different types of demodulators as well as for different signal types to be incidental phase modulated. This paper shows a simple and general analysis for any form of AM-to-PM conversion using derivative form and supposing the video signal to be relatively small. From the analysis, it can be seen how the video-to-video frequency response varies and how much of the lower sideband (LSB), once filtered, will emerge with respect to the amount of AM-to-PM conversion. The general equation to predict the differential phase (DP) and differential gain (DG) degradation caused by AM-to-PM conversion is presented, from which it is shown that there are special AM-to-PM conversion cases that cause no DP and/or DG degradation.
4 citations
TL;DR: The tradeoffs in video deviation, bandwidth, and location of the television sound for frequency modulated television are discussed in this paper and an example of a system design for the Alaskan Bush communities is concluded.
Abstract: Television transmission to small inexpensive earth stations is now being explored using conventional domestic satellites. A number of alternatives exist for the technical formatting of the television signal. Some of the tradeoffs in video deviation, bandwidth, and location of the television sound for frequency modulated television are discussed in this paper. The paper is concluded with an example of a system design for the Alaskan Bush communities.
4 citations
TL;DR: It is observed that so-called "three-dimensional" television has to have a display giving intensity on a four-dimensional space, and not on a three- dimensional space, unless chasiges of perspective with vertical motion of the Viewer are to be discarded.
Abstract: It is observed that so-called "three-dimensional" television has to have a display giving intensity on a four-dimensional space, and not on a three-dimensional space, unless chasiges of perspective with vertical motion of the Viewer are to be discarded. Other errors are noted in the cited papers.
3 citations
TL;DR: Investigations of simple sidelobe suppression techniques, plus an analysis of experimental data on small aperture antennas indicate that much better sidelobe performance can be obtained with a very small cost or performance penalty.
Abstract: The advent of domestic satellite systems and technological improvements in both space and ground equipment makes the use of small aperture earth stations economically feasible and attractive for broadcast satellite applications. With increasing use of the orbit spectrum, there is some concern that broadcast satellite systems may not be able to obtain satisfactory allocations of this orbit-spectrum resource because of interference considerations. Specifilcally, interference calculations based on the present envelope of 9 + 20 log (?/?0) result in comparatively large orbit spacings for broadcast satellites. Theoretical and experimental investigations of simple sidelobe suppression techniques, plus an analysis of experimental data on small aperture antennas (from data over a range of 40 < D/?X < 100), indicate that much better sidelobe performance can be obtained with a very small cost or performance penalty.
3 citations
TL;DR: In this paper, the effects of different typical transmitter and receiver passband characteristics in the vestigial sideband region upon detected transient response are analytically examined, and the effects on transient response of alternate methods for transmitter VSBF phase correction are described.
Abstract: The task of ensuring acceptable detected transient response in consumer television receivers is complicated by the large variety of different transmitter vestigial sideband and receiver IF filter characteristics in use. In this paper, the effects of different typical transmitter and receiver passband characteristics in the vestigial sideband region upon detected transient response are analytically examined. Both envelope and synchronous demodulation systems are investigated, and various levels of carrier modulation are assumed. In addition, the effects on transient response of alternate methods for transmitter vestigial sideband filter (VSBF) phase correction are described. In general, it is found that even with the substantial response of many receiver IF filters in the 1-MHz region of the vestigial sideband, acceptable transient response can be obtained provided that appropriate phase correction of the transmitter VSBF is used. Experimental verification of the analytical results is also presented.
2 citations
TL;DR: Hardware recently developed for space communication can be applied to reach the population in remote areas of countries interested in nationwide distribution of educational television and too limited in size for satellite television.
Abstract: Countries that are interested in nationwide distribution of educational television and are too limited in size for satellite television can utilize their microwave network and microwave towers to reach the population in remote areas. For accomplishing this task some of the hardware recently developed for space communication can be applied.
2 citations
TL;DR: The methods of reducing the visibility of the line raster are discussed and the organization of the designed line-raster processing unit is shown.
Abstract: This paper describes the improvement of image quality effected in a reproduction television system by reducing the visibility of the line raster. The methods of reducing the visibility of the line raster are discussed and the organization of the designed line-raster processing unit is shown. Also an image processed by the line-raster processing unit and a reference image are shown.
2 citations
TL;DR: A new narrow-band TV system called Sampledot, which produces a live picture with motion and sharpness that is a satisfactory replica of conventional TV, is described, and bandwidth compression ratios of 10:1 have been demonstrated with relatively simple electronics.
Abstract: A new narrow-band TV system called Sampledot, which produces a live picture with motion and sharpness that is a satisfactory replica of conventional TV, is described. Bandwidth compression ratios of 10:1 have been demonstrated with relatively simple electronics. Higher compression ratios are projected using the technique with a dynamic display memory or storage. The system is compatible with NTSC or EIA video cameras and monitors. Sampledot works on the principle of gating the line-scan video signal raster with a pseudorandom (PR) dot-sample matrix. About 3 percent, or less, of the picture is sent every fast scan field instead of the usual 50 percent. At the receiving end, the monitor raster is gated in step with the PR matrix. The natural integration effects of the eye-brain characteristics plus optional display memory, the large redundancy of TV video, and the high degree of correlation between adjacent TV pixels are exploited in the Sampledot technique.
TL;DR: A technique for observing and quantitating in real time the frequency excursion of radio signals in the time domain is presented and the concept of percentage band-width occupancy is presented for evaluating the broadcast-signal modulation character.
Abstract: The bandwidth of a signal may be analyzed in terms of what is defined as an observable, or detectable, signal level, the frequency range over which this detectable signal occurs, and the percentage of time that the sigal exceeds defined limits. This paper presents a technique for observing and quantitating in real time the frequency excursion of radio signals in the time domain. A scanning spectrum analyzer interfaced to a minicomputer data-acquisition system is used to collect spectral bandwidth data. The concept of percentage band-width occupancy is presented for evaluating the broadcast-signal modulation character and representative data are given for signals in the FM broadcast band.
TL;DR: In this article, the vestigial sideband RF pulse technique, developed by RCA, more closely simulates TV operation than any other method, and the selection of optimal RE pulse-widths to best reflect correlation with picture quality is discussed.
Abstract: One of the most critical performance characteristics of the TV antenna system is its ability to transmit "ghost-free" pictures. It has been shown that the amount of reflection from the antenna can be correlated to picture quality. How the vestigial sideband RF pulse technique, developed by RCA, more closely simulates TV operation than any other method is discussed. The selection of optimal RE pulse-widths to best reflect correlation with picture quality is discussed. Two RP pulsewidths, one of long duration (up to 2,?s) and the other of shorter duration (0.25, ?s), are recommended for use in antenna test measurements. The RF pulse testing procedure can also be used for measuring the color performance of antenna systems.
TL;DR: In this article, a video processing unit for reproducion of monochrome images is described, and the experimental printing in gravure print is shown and the results are discussed.
Abstract: This paper describes the method of using a television system in image reproduction. The characteristics of photographic material and printing performance are discussed and compared to the performance of a television system. A video processing unit for reproducion of monochrome images is described. The experimental printing in gravure print is shown and the results are discussed.
TL;DR: The combiner to be described is a lumped constants version of a type of combiner which has been realized for a long time in the frequency range in which the distributed constants technique is practicable.
Abstract: The combiner to be described is a lumped constants version of a type of combiner which has been realized for a long time in the frequency range in which the distributed constants technique is practicable [1], [2].
TL;DR: In this article, the authors describe a level measuring instrument of greater precision which may be used by any operator with a minimum of difficulty and report on its use in representative systems using all types of program material.
Abstract: Realizing the reserve, gain system headroom, and transient demands of many of today's complex synthesized and traditional program materials and the far more stringent system performance specifications required when using multi-track recording methods, the need is felt throughout the broadcast and recording industries for a more sophisticated device for more accurate measurement and control of program levels. The waveforms and asymmetries. present in most voice signals and the transient demands imposed upon any system by the newer synthesized sounds render the standard VU meter somewhat less than. adequate for many of today's needs. The continuing quest for the best sound reproduction bespeaks a need for a level measuring instrument of greater precision which may be used by any operator with a minimum of difficulty. This paper describes such a unit and reports on its use in representative systems using all types of program material. Results indicate a favorable response to the new instrument from many experienced operators.