18.20.040 Technical standards | Ida Grove City Code

18.20.040 Technical standards.

Grantee shall at all times comply with all rules and regulations of the Federal Communications Commission and any other duly authorized agency of the United States of America, all laws duly enacted now or hereafter by the United States Congress and all regulations of the Iowa Utilities Board. Without limiting the generality of the foregoing, the cable television system shall meet the following FCC technical standards as of the effective date of the franchise codified in this chapter and shall conform to such standards and all amendments thereto during the term of this franchise:

(a) The aural center frequency of the aural carrier must be 4.5 MHZ ± 5 kHz above the frequency of the visual carrier at the output of the modulating or processing equipment of the cable television system, and at the subscriber terminal.

(b) The RMS voltage of the aural signal shall be maintained between 10 and 17 decibels below the associated visual signal level. This requirement must be met both at the subscriber terminal and at the output of the modulating and processing equipment (generally the headend). For subscriber terminals that use equipment which modulate and remodulate the signal (e.g., baseband converters), the RMS voltage of the aural signal shall be maintained between six and one-half and 17 decibels below the associated visual signal level at the subscriber terminal.

(a) The visual signal level, across a terminating impedance which correctly matches the internal impedance of the cable television system as viewed from the subscriber terminal, shall not be less than one millivolt across an internal impedance of 75 ohms (0 dBmV). Additionally, as measured at the end of a 30-meter (100-foot) cable drop that is connected to the subscriber tap, it shall not be less than 1.41 millivolts across an internal impedance of 75 ohms (+3 dBmV). (At other impedance values, the minimum visual signal level, as viewed from the subscriber terminal, shall be the square root of 0.0133 (Z) millivolts and, as measured at the end of a 30-meter (100-foot) cable drop that is connected to the subscriber tap, shall be two times the square root of 0.00662 (Z) millivolts, where Z is the appropriate impedance value).

(b) The visual signal level on each channel, as measured at the end of a 30-meter cable drop that is connected to the subscriber tap, shall not vary more than eight decibels within any six-month interval, and shall be maintained within:

(i) Three decibels (dB) of the visual signal level of any visual carrier within a six MHZ nominal frequency separation;

(ii) Ten dB of the visual signal level on any other channel on a cable television system of up to 300 MHZ of cable distribution system upper frequency limit, with a one dB increase for each additional 100 MHZ of cable distribution system upper frequency limit (e.g., 11 dB for a system at 301 – 400 MHZ; 12 dB for a system at 401 – 500 MHZ, etc.); and

(iii) A maximum level such that signal degradation due to overload in the subscriber’s receiver or terminal does not occur.

(c) The ratio of RF visual signal level to system noise shall not be less than 43 decibels. For Class I cable television channels, these requirements are applicable only to each signal which is delivered by a cable television system to subscribers within the predicted Grade B contour for that signal; each signal which is first picked up within its predicted Grade B contour; and each signal that is first received by the cable television system by direct video feed from a TV broadcast station, a low power TV station, or a TV translator station.

(d) The ratio of visual signal level to the RMS amplitude of any coherent disturbances such as intermodulation products, second and third order distortions or discrete-frequency interfering signals not operating on proper offset assignments shall be as follows:

(i) The ratio of visual signal level to coherent disturbances shall not be less than 51 decibels for noncoherent channel cable television systems, when measured with modulated carriers and time averaged; and

(ii) The ratio of visual signal level to coherent disturbances which are frequency-coincident with the visual carrier shall not be less than 47 decibels for coherent channel cable systems, when measured with modulated carriers and time averaged.

(e) The peak-to-peak variation in visual signal level caused by undesired low frequency disturbances (hum or repetitive transients) generated within the system, or by inadequate low frequency response, shall not exceed three percent of the visual signal level.

(3) Amplitude Characteristic. The amplitude characteristic shall be within a range of ± two decibels from 0.75 MHZ to 5.0 MHZ above the lower boundary frequency of the cable television channel, referenced to the average of the highest and lowest amplitudes within these frequency boundaries.

(a) Prior to December 30, 1999, the amplitude characteristic may be measured after a subscriber tap and before a converter that is provided and maintained by the cable operator.

(b) As of December 30, 1999, the amplitude characteristic shall be measured at the subscriber terminal.

(4) Terminal Isolation. The terminal isolation provided to each subscriber terminal shall not be less than 18 decibels and shall be sufficient to prevent reflections caused by open-circuited or short-circuited subscriber terminals from producing visible picture impairments at any other subscriber terminal.

(a) The chrominance-luminance delay inequality (or chroma delay), which is the change in delay time of the chrominance component of the signal relative to the luminance component, shall be within 170 nanoseconds.

(b) The differential gain for the color sub-carrier of the television signal, which is measured as the difference in amplitude between the largest and smallest segments of the chrominance signal (divided by the largest and expressed in percent), shall not exceed ±20 percent.

(c) The differential phase for the color sub-carrier of the television signal, which is measured as the largest phase difference in degrees between each segment of the chrominance signal and reference segment, shall not exceed ±10 degrees.

(d) The system shall be so designed, engineered and maintained by grantee so as not to interfere with the television, radio or telephone services of the residents of the city.

This chapter shall be deemed conformed, without further action of the council or grantee, to any and all rules and regulations relating to the required terms of cable television franchises which are now in effect or which may hereafter be adopted by the FCC or any other duly authorized agency of the United States of America, as of the effective date thereof. [Ord. 456, 1996; Code 1975 § 7-3.0404.]