Federal Communications Commission § 76.605

(8) ATSC A/65B: ‘‘ATSC Standard: an internal impedance of 75 ohms (+3 Program and System Information Pro- dBmV). (At other impedance values, tocol for Terrestrial Broadcast and the minimum visual signal level, as Cable (Revision B),’’ March 18, 2003, viewed from the subscriber terminal, IBR approved for § 76.640. shall be the square root of 0.0133 (Z) (9) CEA–542–B: ‘‘CEA Standard: Cable millivolts and, as measured at the end Television Channel Identification of a 30 meter (100 foot) cable drop that Plan,’’ July 2003, IBR approved for is connected to the subscriber tap, § 76.605. shall be 2 times the square root of [68 FR 66734, Nov. 28, 2003, as amended at 69 0.00662(Z) millivolts, where Z is the ap- FR 18803, Apr. 9, 2004; 69 FR 57861, Sept. 28, propriate impedance value.) 2004] (4) The visual signal level on each channel, as measured at the end of a 30 § 76.605 Technical standards. meter cable drop that is connected to (a) The following requirements apply the subscriber tap, shall not vary more to the performance of a cable tele- than 8 decibels within any six-month vision system as measured at any sub- interval, which must include four tests scriber terminal with a matched im- performed in six-hour increments dur- pedance at the termination point or at ing a 24-hour period in July or August the output of the modulating or proc- and during a 24-hour period in January essing equipment (generally the or February, and shall be maintained headend) of the cable television system within: or otherwise as noted. The require- (i) 3 decibels (dB) of the visual signal ments are applicable to each NTSC or level of any visual carrier within a 6 similar video downstream cable tele- MHz nominal frequency separation; vision channel in the system: (ii) 10 dB of the visual signal level on (1)(i) The cable television channels any other channel on a cable television delivered to the subscriber’s terminal system of up to 300 MHz of cable dis- shall be capable of being received and tribution system upper frequency displayed by TV broadcast receivers limit, with a 1 dB increase for each ad- used for off-the-air reception of TV ditional 100 MHz of cable distribution broadcast signals, as authorized under system upper frequency limit (e.g., 11 part 73 of this chapter; and dB for a system at 301–400 MHz; 12 dB (ii) Cable television systems shall transmit signals to subscriber premises for a system at 401–500 MHz, etc.); and equipment on frequencies in accord- (iii) A maximum level such that sig- ance with the channel allocation plan nal degradation due to overload in the set forth in CEA–542–B: ‘‘Standard: subscriber’s receiver or terminal does Cable Television Channel Identifica- not occur. tion Plan,’’ (Incorporated by reference, (5) The rms voltage of the aural sig- see § 76.602). nal shall be maintained between 10 and (2) The aural center frequency of the 17 decibels below the associated visual aural carrier must be 4.5 MHz ±5 kHz signal level. This requirement must be above the frequency of the visual car- met both at the subscriber terminal rier at the output of the modulating or and at the output of the modulating processing equipment of a cable tele- and processing equipment (generally vision system, and at the subscriber the headend). For subscriber terminals terminal. that use equipment which modulate (3) The visual signal level, across a and remodulate the signal (e.g., terminating impedance which cor- baseband converters), the rms voltage rectly matches the internal impedance of the aural signal shall be maintained of the cable system as viewed from the between 6.5 and 17 decibels below the subscriber terminal, shall not be less associated visual signal level at the than 1 millivolt across an internal im- subscriber terminal. pedance of 75 ohms (0 dBmV). Addition- (6) The amplitude characteristic ally, as measured at the end of a 30 shall be within a range of ±2 decibels meter (100 foot) cable drop that is con- from 0.75 MHz to 5.0 MHz above the nected to the subscriber tap, it shall lower boundary frequency of the cable not be less than 1.41 millivolts across television channel, referenced to the

609

VerDate Mar<15>2010 10:13 Dec 13, 2011 Jkt 223205 PO 00000 Frm 00619 Fmt 8010 Sfmt 8010 Y:\SGML\223205.XXX 223205 wreier-aviles on DSK3TPTVN1PROD with CFR § 76.605 47 CFR Ch. I (10–1–11 Edition)

average of the highest and lowest am- petitive transients) generated within plitudes within these frequency bound- the system, or by inadequate low fre- aries. The amplitude characteristic quency response, shall not exceed 3 per- shall be measured at the subscriber ter- cent of the visual signal level. Meas- minal. urements made on a single channel (7) The ratio of RF visual signal level using a single unmodulated carrier to system shall not be less than may be used to demonstrate compli- 43 decibels. For class I cable television ance with this parameter at each test channels, the requirements of this sec- location. tion are applicable only to: (11) As of June 30, 1995, the following (i) Each signal which is delivered by requirements apply to the performance a cable television system to subscribers of the cable television system as meas- within the predicted Grade B contour ured at the output of the modulating for that signal; or processing equipment (generally the (ii) Each signal which is first picked headend) of the system: up within its predicted Grade B con- (i) The -luminance delay tour; inequality (or chroma delay), which is (iii) Each signal that is first received the change in delay time of the chro- by the cable television system by di- minance component of the signal rel- rect video feed from a TV broadcast ative to the luminance component, station, a low power TV station, or a TV translator station. shall be within 170 nanoseconds. (8) The ratio of visual signal level to (ii) The for the color the rms amplitude of any coherent dis- subcarrier of the television signal, turbances such as intermodulation which is measured as the difference in products, second and third order distor- amplitude between the largest and tions or discrete-frequency interfering smallest segments of the chrominance signals not operating on proper offset signal (divided by the largest and ex- assignments shall be as follows: pressed in percent), shall not exceed (i) The ratio of visual signal level to ±20%. coherent disturbances shall not be less (iii) The differential phase for the than 51 decibels for noncoherent chan- color subcarrier of the television signal nel cable television systems, when which is measured as the largest phase measured with modulated carriers and difference in degrees between each seg- time averaged; and ment of the chrominance signal and (ii) The ratio of visual signal level to reference segment (the segment at the coherent disturbances which are fre- of O IRE), shall not ex- quency-coincident with the visual car- ceed ±10 degrees. rier shall not be less than 47 decibels (12) As an exception to the general for coherent channel cable systems, provision requiring measurements to when measured with modulated car- be made at subscriber terminals, and riers and time averaged. without regard to the type of signals (9) The terminal isolation provided to carried by the cable television system, each subscriber terminal: signal leakage from a cable television (i) Shall not be less than 18 decibels. system shall be measured in accord- In lieu of periodic testing, the cable op- ance with the procedures outlined in erator may use specifications provided § 76.609(h) and shall be limited as fol- by the manufacturer for the terminal lows: isolation equipment to meet this standard; and Signal leak- age limit Distance in (ii) Shall be sufficient to prevent re- Frequencies (micro-volt/ meters (m) flections caused by open-circuited or meter) short-circuited subscriber terminals Less than and including 54 from producing visible picture impair- MHz, and over 216 MHz ...... 15 30 ments at any other subscriber ter- Over 54 up to and including 216 minal. MHz ...... 20 3 (10) The peak-to-peak variation in visual signal level caused by undesired (b) Cable television systems distrib- low frequency disturbances (hum or re- uting signals by using methods such as

610

VerDate Mar<15>2010 10:13 Dec 13, 2011 Jkt 223205 PO 00000 Frm 00620 Fmt 8010 Sfmt 8010 Y:\SGML\223205.XXX 223205 wreier-aviles on DSK3TPTVN1PROD with CFR Federal Communications Commission § 76.609

nonconventional coaxial cable tech- system’s use of any type of subscriber equip- niques, noncoaxial copper cable tech- ment or any transmission technology. niques, specialized coaxial cable and [37 FR 3278, Feb. 12, 1972] fiber optical cable hybridization tech- niques or specialized compression tech- EDITORIAL NOTE: For FEDERAL REGISTER ci- tations affecting § 76.605 see the List of CFR niques or specialized receiving devices, Sections Affected, which appears in the and which, because of their basic de- Finding Aids section of the printed volume sign, cannot comply with one or more and at www.fdsys.gov. of the technical standards set forth in paragraph (a) of this section, may be § 76.606 Closed captioning. permitted to operate: Provided, That (a) As of June 30, 1992, the operator of an adequate showing is made pursuant each cable television system shall not to § 76.7 which establishes that the pub- take any action to remove or alter lic interest is benefited. In such in- closed captioning data contained on stances, the Commission may prescribe line 21 of the vertical blanking inter- special technical requirements to en- val. sure that subscribers to such systems (b) As of July 1, 1993, the operator of are provided with an equivalent level each cable television system shall de- of good quality service. liver intact closed captioning data con- NOTE 1: Local franchising authorities of tained on line 21 of the vertical blank- systems serving fewer than 1000 subscribers ing interval, as it arrives at the may adopt standards less stringent than headend or from another origination those in § 76.605(a). Any such agreement shall source, to subscriber terminals and be reduced to writing and be associated with (when so delivered to the cable system) the system’s proof-of-performance records. in a format that can be recovered and NOTE 2: For systems serving rural areas as displayed by decoders meeting § 15.119 defined in § 76.5, the system may negotiate with its local franchising authority for of this chapter. standards less stringent than those in [57 FR 11003, Apr. 1, 1992] §§ 76.605(a)(3), 76.605(a)(7), 76.605(a)(8), 76.605(a)(10) and 76.605(a)(11). Any such agree- § 76.609 Measurements. ment shall be reduced to writing and be asso- ciated with the system’s proof-of-perform- (a) Measurements made to dem- ance records. onstrate conformity with the perform- NOTE 3: The requirements of this section ance requirements set forth in §§ 76.601 shall not apply to devices subject to the TV and 76.605 shall be made under condi- interface device rules under part 15 of this tions which reflect system performance chapter. during normal operations, including NOTE 4: Should subscriber complaints arise the effect of any microwave relay oper- from a system failing to meet § 76.605(a)(6) prior to December 30, 1999, the cable operator ated in the Cable Television Relay will be required to provide a converter that (CARS) Service intervening between will allow the system to meet the standard pickup and the cable distribu- immediately at the complaining subscriber’s tion network. Amplifiers shall be oper- terminal. Further, should the problem be ated at normal gains, either by the in- found to be system-wide, the Commission sertion of appropriate signals or by may order all converters on the system be manual adjustment. Special signals in- changed to meet the standard. serted in a cable television channel for NOTE 5: Should subscriber complaints arise measurement purposes should be oper- from a system failing to meet § 76.605(a)(10), the cable operator will be required to remedy ated at levels approximating those the complaint and perform test measure- used for normal operation. Pilot tones, ments on § 76.605(a)(10) containing the full auxiliary or substitute signals, and number of channels as indicated in nontelevision signals normally carried § 76.601(b)(2) at the complaining subscriber’s on the cable television system should terminal. Further, should the problem be be operated at normal levels to the ex- found to be system-wide, the Commission tent possible. Some exemplary, but not may order that the full number of channels mandatory, measurement procedures as indicated in § 76.601(b)(2) be tested at all required locations for future proof-of-per- are set forth in this section. formance tests. (b) When it may be necessary to re- NOTE 6: No State or franchising authority move the television signal normally may prohibit, condition, or restrict a cable carried on a cable television channel in

611

VerDate Mar<15>2010 10:13 Dec 13, 2011 Jkt 223205 PO 00000 Frm 00621 Fmt 8010 Sfmt 8010 Y:\SGML\223205.XXX 223205 wreier-aviles on DSK3TPTVN1PROD with CFR