HDTV and Old Standards
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Q. What are the current broadcast standards?
The current television standard in North America, Japan and various nations about the world is a 525 line/60 field per second based system called the NTSC (standing for the National Television Systems Committee, the group of manufacturers who in the 40s and 50s established black and white and then color). In Europe, most of Asia, Africa, and South America a system known as PAL is used. PAL is a 625 line /50 field per second color system and dominates the world TV markets in area, though not yet in total unit volume.
NTSC
Channel bandwidth at RF: 6MHz
Horizontal Scanning frequency: 15.750 Hz (monochrome), 15,734 Hz (color)
Aspect ratio: 4 horizontal units, 3 vertical units.
PAL
Channel bandwidth: 8MHz Aspect Ratio: 4 horizontal units, 3 vertical units
SECAM (France)
Channel Bandwidth: 8MHz Aspect ratio: 4 horizontal units, 3 vertical units. |
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Q. What are the current manufacturing standards?
By mandate of the FCC, each receiver sold to the American public today must conform to receive the NTSC television signal. A later mandate to include the UHF tuner in every set was added to this receiver mandate, and finally the service known as closed caption (a teletext system for hearing impaired) was mandated in recent years. The FCC has made voluntary the addition of MTS stereo audio, but has codified it so that both signal providers and set makers know exactly what to build.
In Europe, Asia, South America and across other parts of the world the PAL system is adopted by each state, and often with some unique characteristic, such as the location of the sound carrier. This means for protecting sovereign borders has made for complications in program exchange, though presumably has not impacted the set sales in any of the regions. |
The well respected HDTV FAQ is now available in bound, hard-copy format. Multiple copy discounts apply. Order this definitive industry standard reference securely online. |
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Q. What is wrong with the way it is done?
The NTSC standard has proved to be a durable means of transmitting information to the home via analog methods for over 50 years. However, such analog methods do not lend themselves to bandwidth compression. In light of today's technology the analog transmission of 525 television in 6MHz (equally said for PAL) is universally declared as an inefficient use of very valuable spectrum. Analog also limits the services to very specific definitions, i.e., a color television image transmitting 480 active scanning lines. There is space in the spectrum for additional information and some use is being made of this today under the general umbrella of "data broadcasting within the vertical blanking interval of the NTSC signal." |
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Q. What design limitations do televisions have in terms of picture quality?
The NTSC standard sets the limits in television quality. Only so many scanning lines, so much bandwidth is in the standard. There is also the inclusion of interlace scanning, producing aliasing artifacts, interline noise (often called "twitter"), and dot crawl. In over-the-air and cable transmission there are frequently micro reflections produced, which deliver somewhat delayed second or third harmonic images (which are commonly referred to as ghosting). The NTSC system is a composite system, meaning the color or chrominance information is embedded in the luminace information. That makes perfected separation by way of comb filtering of color and luminance information very expensive, thus color smearing results in most modestly priced sets without this device included. The accumulation of artifacts from the traditional NTSC standard has placed a practical
size limit of the television image since most consumers perceive an increase in size as a "cause" of the artifacts, rather than merely the exposing of them. While filtering techniques have improved, the cross color and dot crawl artifacts, there remains the unalterable fact that the total amount of picture information in the broadcast standard has a specific limit.
A television set could be made to deliver any level of picture quality, but without the economies of scale, which come from adopting a national standard, the cost for doing that is prohibitive. |
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Q. What limitations are set by the government that need to be overcome for television improvements?
The die is cast as far as NTSC television is concerned. There is nothing the government can do to this standard without first an independent development of a technology and extensive testing to determine if it is fully compatible with all existing conditions. At one time there was a proposal from Faroudja Laboratories for a new and more refined NTSC encoder. This encoder would do some preprocessing of the signal that, when received with a corresponding decoder in a TV set, could add quality to the image (similar to that of studio grade 525 component pictures). Still, this would have to be tested by the FCC to determine if the new encoded NTSC was compatible with the sets as they exist today in the marketplace, and, to determine if any added interference resulted. This proposal was withdrawn by its' developer due to the cost of testing and FCC certification. The move to digital high-definition was the only move the government could make to improve the signal quality to the American homes, except where local loop or private recorded material could supply a superior signal and drive the market for superior. There, the government policy is to not involve themselves except where they have been requested on the issue of copy protection. |
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Q. How much does a typical television cost to manufacture?
These are carefully guarded figures among manufacturers. But, in general, there must be sufficient margins to pay for the distribution chain and the service provisions. Estimates are that the factory cost of a television set is about 60% of the retail price. However, there are sets made today that do not provide profits to either their makers nor to their distributors, yet must be kept in the product line in order to have a full competitive compliment of products. The larger the set, the more elaborate the accessories, the larger are the margins. |
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Q. What does it cost the consumer to buy a television set?
The television set of 1998 is a fantastic bargain to the consumers in the United States. In Europe, Japan, and elsewhere they are not such a bargain as is found here, but still far from expensive. There are a few models of black & white television, usually small and portable, that sell retail for under $65.00. Most color models start at plus or minus $150 for a 13 inch set (diagonal measurement). Even for up to 21 inch you will find color sets now aggressively priced under $300. As the size increase, past the 25 inch level the prices move rapidly from the $595 range to $850/$1000. The top of the line Sony and Toshiba Cinema Grade and the RCA Proscan range from $1300 to $2500 (35"). Larger projection sets are usually priced lower per square inch of viewing area than larger CRT models, and range from $1400 (42") to $4200 (60 to 80"). There is a growing market for front projectors, which can display very large images up to 100". Prices range from $3500 to $50,000. Many of these are sold to business (for data projection from computers) and home theater applications. This market is one of the fastest growing segments, but still numbered in the hundreds of thousands of units per year rather than the 24,000,000 units sold per year of more traditional medals. |
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HIGH DEFINITION TELEVISION |
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Q. What are the standards going to be? |
The well respected HDTV FAQ is now available in bound, hard-copy format. Multiple copy discounts apply. Order this definitive industry standard reference securely online. |
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