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120-534: The digital television transition in the United States was the switchover from analog to exclusively digital broadcasting of terrestrial television programming. Under the Digital Transition and Public Safety Act of 2005 , full-power broadcasting of analog television in the United States was initially planned to have ceased after February 17, 2009, but this was delayed to June 12, 2009, after

240-494: A digital cliff effect, by which viewers will receive either a perfect signal or no signal at all with little or no middle ground. Digital transmissions do contain additional data bits to provide error correction for a finite number of bit errors ; once signal quality degrades beyond that point, recovery of the original digital signal becomes impossible, and the image on the screen freezes, or blinks back and forth to totally blank black. The maximum power for DTV broadcast classes

360-492: A "nightlight" service (under SAFER Act provisions) usually displaying a program about the DTV transition, ending no later than July 12, 2009. Low-power broadcasting would continue for some time. Initially scheduled to shut down on September 1, 2015, the conversion date was delayed to July 13, 2021, before finally being completed on January 10, 2022, due to several factors affecting Alaska's conversion to digital television. An attempt

480-623: A billion dollars educating about 60 million people, the National Telecommunications and Information Administration had received $ 5 million a year before the original transition date of February 17, 2009, and the FCC had received $ 2.5 million and was scheduled to receive $ 20 million more later in the year, for 300 million people, requiring voluntary education campaigns. It was also noted that low-income , elderly , disabled , inner city , immigrants, and rural Americans were targeted

600-469: A bulky external battery and mobile ATSC is not yet available. Another option to people would be getting a USB -based TV tuner card for their laptop computer , which in addition to its low costs became a popular option after Microsoft released Windows 7 four months after the DTV transition ended. A Google -sponsored program called Free the Airwaves sought to use the "empty" white space within

720-460: A car stereo equipped with an HD Radio receiver is required to listen to this broadcast. Planning for DTV reception assumed "a properly oriented, high-gain antenna mounted 30 feet in the air outside." The Consumer Electronics Association set up a website called AntennaWeb to identify means to provide the correct signal reception to over-the-air viewers. Another website, TVFool provides geographic mapping and signal data to allow viewers to estimate

840-467: A digital tuner had a unique problem of no longer being able to record programs across multiple channels. In order to record multiple DTV channels, the viewer had to use an external tuner box and set the device to record the output from that box, typically L-1 for the line input. Some manufacturers sold external converter boxes/tuners that automatically changed channels at preset times. The analog VCR or DVR may record at preset times, but will continue recording

960-442: A few broadcasters forced to shut down analog early due to technical problems. On April 12, Nielsen estimated that 3.6 million households remained unready; key problem markets (according to FCC and NTIA) included Albuquerque , Baltimore , Cleveland , Dallas–Fort Worth , Denver , Fresno , Houston , Brownsville , Indianapolis , Los Angeles, Minneapolis–St. Paul , Phoenix , Portland, Oregon , Tulsa , Sacramento , St. Louis ,

1080-627: A given bandwidth. This is because sophisticated comb filters in receivers are more effective with NTSC's 4 color frame sequence compared to PAL's 8-field sequence. However, in the end, the larger channel width of most PAL systems in Europe still gives PAL systems the edge in transmitting more picture detail. In the SECAM television system, U and V are transmitted on alternate lines, using simple frequency modulation of two different color subcarriers. In some analog color CRT displays, starting in 1956,

1200-464: A given signal completely, it is necessary to quote the color system plus the broadcast standard as a capital letter. For example, the United States, Canada, Mexico and South Korea used (or use) NTSC-M , Japan used NTSC-J , the UK used PAL-I , France used SECAM-L , much of Western Europe and Australia used (or use) PAL-B / G , most of Eastern Europe uses SECAM-D / K or PAL-D/K and so on. Not all of

1320-503: A means of television channel selection. Analog broadcast television systems come in a variety of frame rates and resolutions. Further differences exist in the frequency and modulation of the audio carrier. The monochrome combinations still existing in the 1950s were standardized by the International Telecommunication Union (ITU) as capital letters A through N. When color television was introduced,

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1440-659: A midnight February 10 deadline imposed by the FCC, broadcasters disclosed whether they would still cease broadcasting analog signals on the original date of February 17, or if they would delay until June 12, should the DTV Delay Act be signed into law. On February 10, the FCC published the list. 491 stations stated they intended to transition on February 17. The FCC reserved final say on which stations would be allowed to transition on February 17 and which ones would be required to continue analog broadcasts, depending on how many viewers in each market have been determined not ready for

1560-399: A number of different broadcast television systems are in use worldwide, the same principles of operation apply. A cathode-ray tube (CRT) television displays an image by scanning a beam of electrons across the screen in a pattern of horizontal lines known as a raster . At the end of each line, the beam returns to the start of the next line; at the end of the last line, the beam returns to

1680-403: A result of the digital transition. Viewers in rural and mountainous regions were particularly prone to lose all reception after digital transition. U.S. markets which have presented unique problems for digital transition include: There are 80 media markets in which more than 100,000 households receive television signals by over-the-air broadcasts. The reclaimed channels were to be used for

1800-399: A second demodulator, the Z demodulator, also extracts an additive combination of U plus V, but in a different ratio. The X and Z color difference signals are further matrixed into three color difference signals, (R-Y), (B-Y), and (G-Y). The combinations of usually two, but sometimes three demodulators were: In the end, further matrixing of the above color-difference signals c through f yielded

1920-416: A signal which in its analog form reached the edge of Myrtle Beach , could no longer be received by many who had watched the station for years—a victim of a move to UHF 44 at a different transmitter site. WECT's coverage area had been substantially reduced; for many who were on the fringes of the analog NBC 6 signal, WECT was no more. However weeks before, new digital-only WMBF-TV , a new NBC affiliate, came to

2040-462: A signal would not be compatible with monochrome receivers, an important consideration when color broadcasting was first introduced. It would also occupy three times the bandwidth of existing television, requiring a decrease in the number of television channels available. Instead, the RGB signals are converted into YUV form, where the Y signal represents the luminance of the colors in the image. Because

2160-523: A station the advantage to broadcast their audio via FM radio without having to contract with another FM operation to do so. WDSU in New Orleans, Miami's WTVJ and WECT in Wilmington, North Carolina were among the most well-known Channel 6 broadcasters which used this approach to provide emergency information during hurricanes. Digital television, however, does not have this feature, and after

2280-410: A television image is composed of scan lines drawn on the screen. The lines are of varying brightness; the whole set of lines is drawn quickly enough that the human eye perceives it as one image. The process repeats and the next sequential frame is displayed, allowing the depiction of motion. The analog television signal contains timing and synchronization information so that the receiver can reconstruct

2400-399: A toll-free number or a website. The program was paid for with a small part of the $ 20 billion taken in from the DTV spectrum auction. However, these government coupons were limited to an initial sum of $ 890 million (22.25 million coupons) with the option to grow to $ 1.34 billion (33.5 million coupons), which is far short of the estimated 112 million households (224 million redeemable coupons) in

2520-438: A two-dimensional moving image from a one-dimensional time-varying signal. The first commercial television systems were black-and-white ; the beginning of color television was in the 1950s. A practical television system needs to take luminance , chrominance (in a color system), synchronization (horizontal and vertical), and audio signals , and broadcast them over a radio transmission. The transmission system must include

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2640-405: A variety of mobile services, including mobile phones, the now-defunct MediaFLO (55), and public safety (63/64 base , 68/69 mobile). Most of this mobile spectrum has been sold to existing incumbent providers, with AT&T Mobility and Verizon as the largest bidders (see United States 2008 wireless spectrum auction ). The elimination of UHF channels, rather than VHF channels as in the rest of

2760-480: A volt. At this point the IF signal consists of a video carrier signal at one frequency and the sound carrier at a fixed offset in frequency. A demodulator recovers the video signal. Also at the output of the same demodulator is a new frequency modulated sound carrier at the offset frequency. In some sets made before 1948, this was filtered out, and the sound IF of about 22 MHz was sent to an FM demodulator to recover

2880-508: Is Sound-in-Syncs . The luminance component of a composite video signal varies between 0 V and approximately 0.7 V above the black level. In the NTSC system, there is a blanking signal level used during the front porch and back porch, and a black signal level 75 mV above it; in PAL and SECAM these are identical. In a monochrome receiver, the luminance signal is amplified to drive

3000-411: Is a brief (about 1.5 microsecond ) period inserted between the end of each transmitted line of picture and the leading edge of the next line's sync pulse . Its purpose was to allow voltage levels to stabilise in older televisions, preventing interference between picture lines. The front porch is the first component of the horizontal blanking interval which also contains the horizontal sync pulse and

3120-408: Is also substantially lower; one-fifth of the legal limits for the former full-power analog services. This is because there are only eight different states in which an 8VSB signal can be in at any one moment; thus, like all digital transmissions, very little signal is required at the receiver in order to decode it. Nonetheless, this limit is often too low for many stations to reach many rural areas, which

3240-735: Is complete before hurricane season . In some cases, the Federal Communications Commission forced stations to continue full-power analog broadcast of at least a local newscast and information on the digital transition for an additional sixty days—a costly move for individual affected broadcasters. Of 491 stations which had indicated their intention to go digital-only in February 2009, 123 affiliates of four major U.S. commercial networks ( ABC , CBS , Fox , NBC ) were targeted by Federal Communications Commission opposition, precluding or applying additional restrictions to

3360-506: Is easier to tune the picture without losing the sound. So the FM sound carrier is then demodulated, amplified, and used to drive a loudspeaker. Until the advent of the NICAM and MTS systems, television sound transmissions were monophonic. The video carrier is demodulated to give a composite video signal containing luminance, chrominance and synchronization signals. The result is identical to

3480-517: Is not being used for broadcasting. The upper end of this band, 87.5 to 88 MHz, is the lower end of the FM radio band. In the United States, the FCC will occasionally issue a license for 87.9 MHz (though it only does so on rare occurrences and special circumstances; KSFH was the most recent standalone station to use 87.9); 87.7, which is approximately the same frequency as the audio feed of channel 6,

3600-468: Is that the U and V signals are zero when the picture has no color content. Since the human eye is more sensitive to detail in luminance than in color, the U and V signals can be transmitted with reduced bandwidth with acceptable results. In the receiver, a single demodulator can extract an additive combination of U plus V. An example is the X demodulator used in the X/Z demodulation system. In that same system,

3720-405: Is the difference between the B signal and the Y signal, also known as B minus Y (B-Y), and the V signal is the difference between the R signal and the Y signal, also known as R minus Y (R-Y). The U signal then represents how purplish-blue or its complementary color, yellowish-green, the color is, and the V signal how purplish-red or its complementary, greenish-cyan, it is. The advantage of this scheme

Digital television transition in the United States - Misplaced Pages Continue

3840-566: Is the same as the original U signal at the corresponding time. In effect, these pulses are discrete-time analog samples of the U signal. The pulses are then low-pass filtered so that the original analog continuous-time U signal is recovered. For V, a 90-degree shifted subcarrier briefly gates the chroma signal every 280 nanoseconds, and the rest of the process is identical to that used for the U signal. Gating at any other time than those times mentioned above will yield an additive mixture of any two of U, V, -U, or -V. One of these off-axis (that is, of

3960-542: Is transmitted. Therefore, the receiver must reconstitute the subcarrier. For this purpose, a short burst of the subcarrier, known as the colorburst, is transmitted during the back porch (re-trace blanking period) of each scan line. A subcarrier oscillator in the receiver locks onto this signal (see phase-locked loop ) to achieve a phase reference, resulting in the oscillator producing the reconstituted subcarrier. NTSC uses this process unmodified. Unfortunately, this often results in poor color reproduction due to phase errors in

4080-554: Is used by some television licenses to broadcast primarily to radio, such as Pulse 87 's stations. In Japan and some former Soviet republics frequencies lower than 87 MHz are still used for the FM broadcast band . In Brazil, with the phasing out of the PAL-M analog broadcasts, AM radio stations have been migrated to a new FM radio band between the frequencies from former analog TV channels A5 and A6 (76.1Mhz to 87.5Mhz) called Extended FM or e-FM. The 6-meter band (50 MHz) and

4200-475: Is used to build the image. This process doubles the apparent number of video frames per second and further reduces flicker and other defects in transmission. The television system for each country will specify a number of television channels within the UHF or VHF frequency ranges. A channel actually consists of two signals: the picture information is transmitted using amplitude modulation on one carrier frequency, and

4320-413: Is used to reduce the channel spacing, which would be nearly twice the video bandwidth if pure AM was used. Signal reception is invariably done via a superheterodyne receiver : the first stage is a tuner which selects a television channel and frequency-shifts it to a fixed intermediate frequency (IF). The signal amplifier performs amplification to the IF stages from the microvolt range to fractions of

4440-589: The CRTC followed suit in placing a moratorium on future television stations using Channel 51 for broadcast use, to prevent ACI to the A-Block of the 700MHz band. Now that the switch from analog to digital broadcasts is complete, analog TVs are incapable of receiving over-the-air broadcasts without the addition of a set-top converter box. Consequently, a digital-to-analog converter, an electronic device that connects to an analog television , must be used in order to allow

4560-492: The ITU in 1961 as: A, B, C, D, E, F, G, H, I, K, K1, L, M and N. These systems determine the number of scan lines, frame rate, channel width, video bandwidth, video-audio separation, and so on. A color encoding scheme ( NTSC , PAL , or SECAM ) could be added to the base monochrome signal. Using RF modulation the signal is then modulated onto a very high frequency (VHF) or ultra high frequency (UHF) carrier wave . Each frame of

4680-490: The San Francisco Bay Area , Salt Lake City , and Seattle . On February 11, 2009, the FCC announced it would allow 368 of the 491 applied stations to go all-digital on the original February 17 date, 100 of which will be allowed to use their analog signal to inform unprepared viewers of the new transition date, or for emergency situations such as severe weather (called "nightlighting"). The FCC concluded that

4800-455: The System B standard. This channel was also widely used by private local stations until the switch over to DVB-T . Some countries used slightly different frequencies or don't use Band 1 at all for terrestrial broadcast television. The fast growing of digital television as well as the susceptibility of this band to interference during E skip events in all European countries was accompanied by

4920-430: The back porch . The back porch is the portion of each scan line between the end (rising edge) of the horizontal sync pulse and the start of active video. It is used to restore the black level (300 mV) reference in analog video. In signal processing terms, it compensates for the fall time and settling time following the sync pulse. In color television systems such as PAL and NTSC, this period also includes

Digital television transition in the United States - Misplaced Pages Continue

5040-465: The colorburst signal. In the SECAM system, it contains the reference subcarrier for each consecutive color difference signal in order to set the zero-color reference. In some professional systems, particularly satellite links between locations, the digital audio is embedded within the line sync pulses of the video signal, to save the cost of renting a second channel. The name for this proprietary system

5160-534: The control grid in the electron gun of the CRT. This changes the intensity of the electron beam and therefore the brightness of the spot being scanned. Brightness and contrast controls determine the DC shift and amplification, respectively. A color signal conveys picture information for each of the red, green, and blue components of an image. However, these are not simply transmitted as three separate signals, because: such

5280-531: The 123 stations in "at-risk" markets to proceed unless they certify with the agency by 6 pm ET on February 13 that they comply with eight additional requirements, including ensuring that at least one station that is currently providing analog service to an area within the DMA provides DTV transition and emergency information, as well as local news and public affairs programming ("enhanced nightlight" service) for at least 60 days following February 17. On February 13,

5400-589: The FCC for assistance. Officials were concerned by the implications of this for larger markets or those where reliance on over the air broadcasts exceeds 30%. While many calls from viewers were straightforward questions about the installation of antennas and converters, or the need to scan for channels before being able to watch digital television, hundreds more were from viewers who had installed converters and UHF antennas correctly but had still lost existing channels. Most affected were full-power broadcasters which had been on low-VHF channels. WECT ( NBC 6 Wilmington),

5520-453: The FCC said 53 of the applied 106 at risk stations had qualified to go all digital on February 17. The other 43 qualified for nightlight service; 10 others could not comply with the nightlight clause. The total number stations which became digital only on February 17 was 421. Analog TV Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast,

5640-572: The Fourth, Valentine's Day— there are going to be some people that aren't ready." On January 29, the DTV Delay Act passed in the Senate. On February 4, the House also approved this measure. The bill was submitted to President Obama on February 4, who did not immediately sign it into law. On February 9, President Obama posted the bill on whitehouse.gov , giving the public five days to weigh in on it. Under

5760-577: The French former 455-line (1937-1939) then 441-line (1943-1956) transmitter on the Eiffel Tower in Paris , and some stations of the French monochrome 819-line system used Band I. Both 405-line and 819-line systems were discontinued in the mid-1980s. Other European countries used Band I for 625-line analogue television, first in monochrome and later in colour. This was being gradually phased out with

5880-734: The L-1 line input, which would be the same channel unless the channel is manually changed. Alternatively, the user may purchase a new TV, DVR, or DVD recorder with a built-in digital tuner. However, these newer technologies have their own drawbacks, such as being limited to only 1–2 hours with high-quality XP mode (DVD-R). A major concern is that the broadcast technology used for ATSC signals called 8VSB has problems receiving signals inside buildings and in urban areas, largely due to multipath reception issues which cause ghosting and fading on analog images, but can also lead to intermittent signal or no reception at all on ATSC programs. DTV broadcasts exhibit

6000-408: The NTSC and PAL color systems, U and V are transmitted by using quadrature amplitude modulation of a subcarrier. This kind of modulation applies two independent signals to one subcarrier, with the idea that both signals will be recovered independently at the receiving end. For NTSC, the subcarrier is at 3.58 MHz. For the PAL system it is at 4.43 MHz. The subcarrier itself is not included in

6120-411: The NTSC system. PAL's color encoding is similar to the NTSC systems. SECAM, though, uses a different modulation approach than PAL or NTSC. PAL had a late evolution called PALplus , allowing widescreen broadcasts while remaining fully compatible with existing PAL equipment. In principle, all three color encoding systems can be used with any scan line/frame rate combination. Therefore, in order to describe

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6240-405: The U and V axis) gating methods is called I/Q demodulation. Another much more popular off-axis scheme was the X/Z demodulation system. Further matrixing recovered the original U and V signals. This scheme was actually the most popular demodulator scheme throughout the 1960s. The above process uses the subcarrier. But as previously mentioned, it was deleted before transmission, and only the chroma

6360-461: The United States. Nevertheless, not every household took advantage of the offer, as reports indicate half of all households already had at least one digital TV. In January 2009, the NTIA began placing coupon requests on a waiting list after the program reached its maximum allowed funding. New requests for coupons were fulfilled only after unredeemed coupons expired. These coupons could be redeemed toward

6480-407: The Y signal) represents the approximate saturation of a color, and the chrominance phase against the subcarrier reference approximately represents the hue of the color. For particular test colors found in the test color bar pattern, exact amplitudes and phases are sometimes defined for test and troubleshooting purposes only. Due to the nature of the quadrature amplitude modulation process that created

6600-414: The air to serve Myrtle Beach with a city-grade signal; like WECT, WMBF was owned by Raycom Media at the time. On November 7, 2008, the FCC issued an order allowing distributed transmission systems (DTS) to be constructed by stations that otherwise cannot cover their original analog footprint with their new digital channels and facilities. While broadcasters may now apply for DTS facilities, this decision

6720-562: The analog switch-off, the FCC reallocated channels 52 through 69 (the 700MHz band) for other communications traffic, completing the reallocation of broadcast channels 52–69 that began in the late 1990s. These channels were auctioned off in early 2008, with the winning bidders taking possession of them in June 2009. Four channels from this portion of the broadcast spectrum (60, 61, 68, and 69) were held for reallocation to public safety communications (such as police, fire, and emergency rescue). Some of

6840-653: The band was subdivided into three channels, each being 7 MHz wide: Italy also used a "outband" "channel C" (video : 82.25 MHz - audio : 87.75 MHz). It was used by the first transmitter brought in service by the RAI in Torino in the 1950s which was previously used in WW2 by the US to broadcast NTSC TV on channel A6 for military purposes, later donated to Italy, it had its video carrier shifted 1 MHz lower to accommodate

6960-435: The basic sound signal. In newer sets, this new carrier at the offset frequency was allowed to remain as intercarrier sound , and it was sent to an FM demodulator to recover the basic sound signal. One particular advantage of intercarrier sound is that when the front panel fine tuning knob is adjusted, the sound carrier frequency does not change with the tuning, but stays at the above-mentioned offset frequency. Consequently, it

7080-423: The beginning of the first line at the top of the screen. As it passes each point, the intensity of the beam is varied, varying the luminance of that point. A color television system is similar except there are three beams that scan together and an additional signal known as chrominance controls the color of the spot. When analog television was developed, no affordable technology for storing video signals existed;

7200-567: The bill into law, officially moving the cutoff date to June 12, 2009. In total, 191 stations already had turned off their analog transmitters for good. On February 20, 2009, the FCC released an order stating that stations that wish to go all digital before the final June 12, 2009, date must inform the FCC of that decision by March 17, 2009. While 93 large-city network owned and operated stations (controlled by CBS , ABC , NBC , Fox , and Univision ) would continue analog broadcasts until June 12, many small-market broadcasters were unable to justify

7320-435: The bill passed, and any frequencies freed up by such action could be used by fire and police departments and other emergency services . Those whose converter box coupons had expired would be allowed to apply for new coupons. The House postponed a similar bill (by House Energy and Commerce Committee Chairman Henry Waxman ), until the Senate's version was complete. The Senate unanimously voted on January 26, 2009, to delay

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7440-455: The bill. Hutchison supported the idea because Rockefeller did not intend to ask for another postponement. On January 22, The Nielsen Company said 6.5 million Americans had not prepared for the switch. Opponents pointed out that TV stations would face extra operating expenses, and those who paid to use the spectrum to be made available would have to wait. Under later amendments, stations could choose to end analog broadcasts before June 12 even if

7560-419: The brightness control signal ( luminance ) is fed to the cathode connections of the electron guns, and the color difference signals ( chrominance signals) are fed to the control grids connections. This simple CRT matrix mixing technique was replaced in later solid state designs of signal processing with the original matrixing method used in the 1954 and 1955 color TV receivers. Synchronizing pulses added to

7680-421: The brightness, colors and sound are represented by amplitude , phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes snowy and subject to interference. In contrast, picture quality from a digital television (DTV) signal remains good until

7800-525: The chrominance information was added to the monochrome signals in a way that black and white televisions ignore. In this way backward compatibility was achieved. There are three standards for the way the additional color information can be encoded and transmitted. The first was the American NTSC system. The European and Australian PAL and the French and former Soviet Union SECAM standards were developed later and attempt to cure certain defects of

7920-436: The chrominance signal, at certain times, the signal represents only the U signal, and 70 nanoseconds (NTSC) later, it represents only the V signal. About 70 nanoseconds later still, -U, and another 70 nanoseconds, -V. So to extract U, a synchronous demodulator is utilized, which uses the subcarrier to briefly gate the chroma every 280 nanoseconds, so that the output is only a train of discrete pulses, each having an amplitude that

8040-425: The combining process, the low-resolution portion of the Y signals cancel out, leaving R, G, and B signals able to render a low-resolution image in full color. However, the higher resolution portions of the Y signals do not cancel out, and so are equally present in R, G, and B, producing the higher-resolution image detail in monochrome, although it appears to the human eye as a full-color and full-resolution picture. In

8160-486: The composite video format used by analog video devices such as VCRs or CCTV cameras . To ensure good linearity and thus fidelity, consistent with affordable manufacturing costs of transmitters and receivers, the video carrier is never modulated to the extent that it is shut off altogether. When intercarrier sound was introduced later in 1948, not completely shutting off the carrier had the side effect of allowing intercarrier sound to be economically implemented. Each line of

8280-452: The coupon amount, which in effect reduced its value by about $ 3 (based on 7.5% tax). There has been possible evidence that the presence of the government coupon program has inflated the prices of converter boxes by between $ 21 and $ 34 above what they would be otherwise. These converter boxes require royalties to be paid to license the MPEG-2 and ATSC patents, which may contribute (for example,

8400-634: The development of the cathode-ray tube (CRT), which uses a focused electron beam to trace lines across a phosphor coated surface. The electron beam could be swept across the screen much faster than any mechanical disc system, allowing for more closely spaced scan lines and much higher image resolution. Also, far less maintenance was required of an all-electronic system compared to a mechanical spinning disc system. All-electronic systems became popular with households after World War II . Broadcasters of analog television encode their signal using different systems. The official systems of transmission were defined by

8520-424: The digital TV transition to June 12, 2009. However, the House of Representatives voted on and defeated a similar measure on January 28. Rep. Joe Barton led the movement in the House to defeat the measure, saying that "the DTV transition is neither stuck nor broke", and that any problems with the DTV transition can be fixed. Barton also said, "I guarantee you, no matter when you set the date— February 17, June 12, July

8640-503: The disc to scan an image. A similar disk reconstructed the image at the receiver. Synchronization of the receiver disc rotation was handled through sync pulses broadcast with the image information. Camera systems used similar spinning discs and required intensely bright illumination of the subject for the light detector to work. The reproduced images from these mechanical systems were dim, very low resolution and flickered severely. Analog television did not begin in earnest as an industry until

8760-417: The displayed image is transmitted using a signal as shown above. The same basic format (with minor differences mainly related to timing and the encoding of color) is used for PAL, NTSC , and SECAM television systems. A monochrome signal is identical to a color one, with the exception that the elements shown in color in the diagram (the colorburst , and the chrominance signal) are not present. The front porch

8880-528: The existing Japanese FM radio service (which begins at 76 MHz) for use as an extension to the existing North American FM broadcast band. On August 22, 2011, the United States ' Federal Communications Commission announced a freeze on all future applications for broadcast stations requesting to use channel 51, to prevent adjacent-channel interference (ACI) to the A-Block of the 700MHz band. Later that year (on December 16, 2011), Industry Canada and

9000-411: The extra cost, with non-commercial and independent stations very adversely affected. No funding was provided to reimburse broadcasters who incurred additional costs due to the DTV Delay Act. Public Broadcasting Service CEO Paula Kerger had estimated a $ 22 million cost to the nation's PBS member stations to extend simulcasting until June 12; more than a hundred PBS stations ultimately elected to stick to

9120-407: The first market in the nation to go digital-only. Wilmington was chosen as the test city in part because the area's digital channel positions would remain unchanged after the transition. Wilmington was also appropriate because it had no hills to cause reception problems and all of the stations would have UHF channels. The low-power CBS affiliate WILM-LD signed on its new digital signal in time for

9240-521: The introduction of digital television in the DVB-T standard, which is not defined for VHF Band I, though some older receivers and some modulators do support it. In the United States, use of this band is for analog NTSC (ended June 12, 2009 for high power stations) and digital ATSC (current). Digital television has problems with impulse noise interference, particularly in this band. In European countries that used System B for television broadcasting,

9360-462: The low-VHF (channels 2–6) did not return to these frequencies after the transition. About 40 stations remained in the low- VHF after the transition, with the majority in smaller markets (with a few notable exceptions). The FCC has long discouraged the digital allocation on low-VHF channels for several reasons: higher ambient noise, interference with FM radio (channel 6 borders FM at 88 MHz), and larger antenna size required for these channels. After

9480-401: The luminance signal had to be generated and transmitted at the same time at which it is displayed on the CRT. It was therefore essential to keep the raster scanning in the camera (or other device for producing the signal) in exact synchronization with the scanning in the television. The physics of the CRT require that a finite time interval be allowed for the spot to move back to the start of

9600-435: The modulated signal ( suppressed carrier ), it is the subcarrier sidebands that carry the U and V information. The usual reason for using suppressed carrier is that it saves on transmitter power. In this application a more important advantage is that the color signal disappears entirely in black and white scenes. The subcarrier is within the bandwidth of the main luminance signal and consequently can cause undesirable artifacts on

9720-410: The most, because these groups mainly watch analog antenna TV more than any other groups. While broadcasters were forced by Federal Communications Commission regulations to devote the equivalent of more than a billion dollars worth of airtime to public service announcements regarding the digital transition, the amount of information conveyed in these short advertisements was by necessity limited. Both

9840-410: The negative side-effect of causing image smearing and blurring when there is rapid on-screen motion occurring. The maximum frame rate depends on the bandwidth of the electronics and the transmission system, and the number of horizontal scan lines in the image. A frame rate of 25 or 30 hertz is a satisfactory compromise, while the process of interlacing two video fields of the picture per frame

9960-451: The next line ( horizontal retrace ) or the start of the screen ( vertical retrace ). The timing of the luminance signal must allow for this. The human eye has a characteristic called phi phenomenon . Quickly displaying successive scan images creates the illusion of smooth motion. Flickering of the image can be partially solved using a long persistence phosphor coating on the CRT so that successive images fade slowly. However, slow phosphor has

10080-399: The number of channels which will be gained or lost as a result of digital transition; while it estimated that marginally more stations would be gained than lost by viewers, this varied widely with viewers of low-VHF analog signals in distant-fringe areas among the most adversely affected. An estimated 1.8 million people were expected to lose the ability to access over-the-air TV entirely as

10200-517: The on-air announcements and government-funded telephone hotlines receiving viewer inquiries directed consumers to Internet sites to seek information, at a time when most affected were not familiar with the Internet. After the switch, consumers' old analog televisions, VCRs, DVRs, and other devices which lacked a digital tuner no longer received over-the-air television, though previously recorded content can still be replayed. The one, direct solution to

10320-568: The option of programming multiple digital subchannels (multicasting). However, it provides these advantages at the cost of a severe limitation of broadcast range. Digital signals do not have "grade B" signal areas, and are either "in perfectly" or "not in at all". Further, since most stations have preferred to use UHF rather than older VHF channel allocations, their actual broadcast range is far less than previously. Viewers in major metropolitan areas will likely not notice problems; however, rural TV users have generally had most and in some events all of

10440-544: The original deadline. Some individual commercial station groups, most notably Sinclair Broadcast Group and Gray Television , shut down the vast majority of their analog signals on the original deadline. Others left the question to their individual local stations. Many local markets, ranging from Burlington, Vermont and Sioux City, Iowa to San Diego, lost analog signals from most or all major U.S. stations. Some stations in coastal regions such as Fort Myers, Florida had chosen not to wait until June 12 so as to ensure transition

10560-456: The other 123 stations who applied present a "significant risk of substantial public harm," if they go all digital on February 17. The FCC stated "We considered the presence of major networks and their affiliates critical to ensuring that viewers have access to local news and public affairs available over the air because the major network affiliates are the primary source of local broadcast news and public affairs programming". The FCC would not permit

10680-674: The passage of the DTV Delay Act on February 4, 2009. This date was a further delay from the original date of December 31, 2006, as stipulated in the Telecommunications Act of 1996 . The delay to June 12 was to assist households on a waiting list for coupons for digital converter boxes , funding for which was provided by the American Recovery and Reinvestment Act of 2009 . While full-power broadcasting ceased on June 12, 120 full power stations would maintain

10800-452: The phase of the signal on each successive line, and averaging the results over pairs of lines. This process is achieved by the use of a 1H (where H = horizontal scan frequency) duration delay line. Phase shift errors between successive lines are therefore canceled out and the wanted signal amplitude is increased when the two in-phase ( coincident ) signals are re-combined. NTSC is more spectrum efficient than PAL, giving more picture detail for

10920-488: The picture, all the more noticeable in black and white receivers. A small sample of the subcarrier, the colorburst , is included in the horizontal blanking portion, which is not visible on the screen. This is necessary to give the receiver a phase reference for the modulated signal. Under quadrature amplitude modulation the modulated chrominance signal changes phase as compared to its subcarrier and also changes amplitude. The chrominance amplitude (when considered together with

11040-739: The possible combinations exist. NTSC is only used with system M, even though there were experiments with NTSC-A ( 405 line ) in the UK and NTSC-N (625 line) in part of South America. PAL is used with a variety of 625-line standards (B, G, D, K, I, N) but also with the North American 525-line standard, accordingly named PAL-M . Likewise, SECAM is used with a variety of 625-line standards. For this reason, many people refer to any 625/25 type signal as PAL and to any 525/30 signal as NTSC , even when referring to digital signals; for example, on DVD-Video , which does not contain any analog color encoding, and thus no PAL or NTSC signals at all. Although

11160-472: The problem was to buy an external tuner (called a converter box ) that receives DTV signals directly and converts them to analog for the television, VCR, or other analog device. Another solution was the use of cable TV or satellite TV service, as these providers handled the necessary conversion within their respective systems and could provide the analog signal these older analog devices required. Users of analog VCRs, DVRs, or other recording devices which lacked

11280-474: The progressive closedown of band I analog transmitters from 2006 to 2020. In the countries that use System D television broadcast system, the channel allocation in the VHF-I band is as follows: Russia, Ukraine, Kazakhstan and a few other countries still broadcast analog TV on Band I in 2023. The band is subdivided into five channels for television broadcasting, each occupying 6 MHz ( System M ). Channel 1

11400-441: The purchase of a digital-to-analog converter at brick and mortar , on-line, and telephone retailers that had completed the NTIA certification process. Retail prices for the boxes range from $ 40 to $ 70 (plus tax and/or shipping); after applying the coupons, the price to the consumer would be between $ 5 and $ 40 per box. Because it was actually used as a payment , despite the name " coupon ", consumers paid state and local sales tax on

11520-468: The received signal, caused sometimes by multipath, but mostly by poor implementation at the studio end. With the advent of solid-state receivers, cable TV, and digital studio equipment for conversion to an over-the-air analog signal, these NTSC problems have been largely fixed, leaving operator error at the studio end as the sole color rendition weakness of the NTSC system. In any case, the PAL D (delay) system mostly corrects these kinds of errors by reversing

11640-491: The relatively longer wavelength low-VHF channels. Stations that broadcast in analog on channel 6 have had an additional benefit of having its audio feed broadcast on 87.7 MHz, which is at the very low end of the FM radio dial. As such, many stations that use channel 6 have taken advantage of this, and directly promote this feature, especially during drive time newscasts, and as a critical conduit of information in markets where severe weather (such as hurricanes ) allowed

11760-433: The remaining TV for unlicensed use, like for Wi-Fi . In March 2008, the FCC requested public comment on turning the bandwidth currently occupied by analog television channels 5 and 6 (76–88 MHz) over to extending the FM broadcast band when the digital television transition was to be completed in February 2009 (ultimately delayed to June 2009). This proposed allocation would effectively assign frequencies corresponding to

11880-551: The remaining freed up frequencies were used for advanced commercial wireless services for consumers, such as Qualcomm 's planned use of former UHF channel 55 for its MediaFLO service. According to David Rehr, then president and CEO of the National Association of Broadcasters , this transition represented "the most significant advancement of television technology since color TV was introduced." The then-new FCC chairman Julius Genachowski said on June 30, 2009, that

12000-432: The rendering of colors in this way is the goal of both monochrome film and television systems, the Y signal is ideal for transmission as the luminance signal. This ensures a monochrome receiver will display a correct picture in black and white, where a given color is reproduced by a shade of gray that correctly reflects how light or dark the original color is. The U and V signals are color difference signals. The U signal

12120-523: The royalties for ATSC were $ 5 per receiver). On January 21, 2009, Senator Jay Rockefeller introduced a bill in the Senate titled the DTV Delay Act because millions of Americans would not be ready for the cutoff on February 17 due to a shortage of converter box coupons, and planning that the transition date be moved to June 12. Rockefeller, chairman of the Committee on Commerce, Science and Transportation , and Sen. Kay Bailey Hutchison , worked together on

12240-550: The shutdown of their analog signals in markets where the only analog service remaining after the February 17 shutdown would have been an independent or educational broadcaster, an adjacent-market station or a low-power station. Of approximately 1,800 U.S. full-service TV stations, an additional 190 were already digital-only before February 2009; these included Hawaii (digital since January 2009), Zanesville, Ohio (digital since July 2008), and Wilmington, North Carolina (the FCC's 2008 digital test market), as well as some new stations and

12360-446: The signal level drops below a threshold where reception is no longer possible or becomes intermittent. Analog television may be wireless ( terrestrial television and satellite television ) or can be distributed over a cable network as cable television . All broadcast television systems used analog signals before the arrival of DTV. Motivated by the lower bandwidth requirements of compressed digital signals , beginning just after

12480-415: The sound is transmitted with frequency modulation at a frequency at a fixed offset (typically 4.5 to 6 MHz) from the picture signal. The channel frequencies chosen represent a compromise between allowing enough bandwidth for video (and hence satisfactory picture resolution), and allowing enough channels to be packed into the available frequency band. In practice a technique called vestigial sideband

12600-467: The stations they previously received with acceptable but not "perfect" signals fall over the digital cliff (where analog signals slowly degrade over long distances rather than digital suddenly cutting off when out of range). Lastly, many low-power broadcasters have been temporarily permitted to transmit in analog for several years. Although the United Kingdom spent the equivalent of more than

12720-510: The television to receive digital broadcasts. The box may also be called a "set-top" converter, "digital TV adapter" (DTA), or "digital set-top box" (DSTB). To assist consumers through the conversion, the Department of Commerce through its National Telecommunications and Information Administration (NTIA) division handled requests from households for up to two $ 40 coupons for digital-to-analog converter boxes beginning January 1, 2008, via

12840-434: The three color-difference signals, (R-Y), (B-Y), and (G-Y). The R, G, and B signals in the receiver needed for the display device (CRT, Plasma display, or LCD display) are electronically derived by matrixing as follows: R is the additive combination of (R-Y) with Y, G is the additive combination of (G-Y) with Y, and B is the additive combination of (B-Y) with Y. All of this is accomplished electronically. It can be seen that in

12960-466: The transition had "succeeded far beyond expectations", but his predecessor Michael Copps said that the transition led to a "significant impact on consumers" and that it was "not a closed book". As part of a test by the FCC to iron out transition and reception concerns before the nationwide shutoff, all of the major commercial network stations in the Wilmington, North Carolina market ceased transmission of their analog signals on September 8, 2008, making it

13080-411: The transition, many viewers using "high-definition" antennas have reported problems receiving stations that broadcast on VHF channels. This is because some of the new antennas marketed as "HDTV antennas" from manufacturers such as Channel Master were only designed for channels 7–51 and are more compact than their channel 2–69 counterparts. These manufacturers did not anticipate widespread continued use of

13200-550: The transition, this additional method of reception is no longer available. WRGB , channel 6 in Albany, New York , used a separate transmitter on 87.7 that transmitted a vertically polarized analog audio signal, which would theoretically avoid interference with the horizontally polarized digital TV signal. This would allow the station to keep its audio on 87.7 FM after the transition to digital. WRGB ran this transmitter for approximately 6 weeks on an experimental basis, only to find that

13320-414: The transition. Most O&O stations of six major networks ( ABC , CBS , Fox , NBC , Univision , and Telemundo , plus The CW , MyNetworkTV , TeleFutura , and independent stations ), as well as the station groups of Gannett , Hearst-Argyle , and Meredith , committed to keeping all or most of their analog signals active until the new June 12 cutoff date. On February 11, 2009, President Obama signed

13440-455: The transition. The test excluded UNC-TV / PBS station WUNJ , which kept their analog signal on, as they were the official conduit of emergency information in the area. Viewers were notified of the change by months of public service announcements, town hall meetings, and local news coverage. Only 7% of viewers were affected by the loss of analog broadcasts, the remainder subscribing to cable or satellite services, but this produced 1,800 calls to

13560-438: The twenty kilowatt limit of low- VHF DTV) or abandoning a frequency which it occupied since the 1950s in order to transmit more power (up to 1000 kW) on the less-crowded UHF TV band. Such stations can keep the same channel number, however, because of ATSC virtual channels . The higher frequencies are challenged in areas where signals must travel great distances or encounter significant terrestrial obstacles. Most stations in

13680-558: The vertically polarized 87.7 MHz signal interfered with the digital video, while broadcast of analog signals on 87.9 MHz met with FCC objections. WITI in Milwaukee took a more direct though still experimental approach to restore their TV audio, having it restored in August 2009 to an HD Radio subchannel of WMIL-FM via a content agreement with WMIL owner Clear Channel Communications . A purchase of HD Radio equipment or having

13800-497: The video signal at the end of every scan line and video frame ensure that the sweep oscillators in the receiver remain locked in step with the transmitted signal so that the image can be reconstructed on the receiver screen. Band I Channel spacings vary from country to country, with spacings of 6, 7 and 8 MHz being common. In the UK, Band I was originally used by the BBC for monochrome 405-line television ; likewise,

13920-618: The world, precludes the use of band III (high VHF) for Digital Audio Broadcasting as is used in a few other countries. It also makes more difficult the reassignment of channels 5 and 6 (76 to 88MHz) to expand the FM radio broadcast band. There are also no channels set aside for analog broadcasts of the Emergency Alert System , rendering most portable emergency TV sets useless. While a small number of portable ATSC sets have started to appear, these are costly. A portable converter box (such as Winegard's RCDT09A) would require

14040-492: The year 2000, a digital television transition is proceeding in most countries of the world, with different deadlines for the cessation of analog broadcasts. Several countries have made the switch already, with the remaining countries still in progress mostly in Africa, Asia, and South America. The earliest systems of analog television were mechanical television systems that used spinning disks with patterns of holes punched into

14160-408: Was an alleged benefit in the FCC's choice of ATSC and 8VSB over worldwide-standard DVB-T and its COFDM modulation . Additionally, without the hierarchical modulation of DVB, signal loss is complete, and there is no switch to a lower resolution before this occurs. A hundred-kW analog station on TV channels 2 to 6 would therefore be faced with the choice of either lowering its power by 80% (to

14280-491: Was made far too late to allow the extra transmitter sites to be constructed and operational before the original February 17, 2009, analog shutoff. On February 8, 2006, President George W. Bush signed the Deficit Reduction Act of 2005 bill to end analog television by February 17, 2009. Digital TV encoding allows stations to offer higher definition video and better sound quality than analog, as well as allowing

14400-518: Was made in 2007 to extend analog services by another five years in areas within 80 kilometers (50 miles) of the Mexican border, but it was unsuccessful. In preparation for the end of analog services, all new television devices that receive signals over-the-air, including pocket-sized portable televisions , personal computer video capture card tuners, and DVD recorders , had been required to include digital ATSC tuners since March 1, 2007. Following

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