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(a) Measurements made to demonstrate conformity with the performance requirements set forth in these technical standards shall be made under conditions which reflect network performance during normal operations, including the effect of any present or future microwave relay operated in the Community Antenna Relay Service (CARS) intervening between pickup antenna and the broadband telecommunication network and including the effects of any microwave local distribution service which may be a part of the network.
Special signals inserted in a cable television channel for measurement purposes should be operated at levels approximating those used for normal operation. Pilot tones, auxiliary signals, and nontelevision signals normally carried on the network should be operated at normal levels. The following test procedures are included as a guide. There are several recognized and technically acceptable methods for performing many of the measurements, the technique and equipment used in each case, if different than those set forth herein shall be fully described in the annual certification to the City.
(b) When it may be necessary to remove the television signal normally carried on a cable television channel in order to facilitate a performance measurement, it will be permissible to disconnect the antenna which serves the channel under measurement and to substitute therefor a matching resistance termination. Other inputs should be connected to maintain the equivalent to, or special test signals on, other channels to ascertain network performance.
(c) As may be necessary to ensure satisfactory service to a subscriber, the City may require additional tests to demonstrate network performance or may specify the use of different test procedures.
(d) Network frequency response measurements may be made with a calibrated signal generator, variable attenuator and a frequency selective voltmeter. All TV signals except for ALC, AGC, or ASC pilot carriers may be disconnected during this test. With all automatic gain control amplifiers in the section under test set to their normal operating mode, the signal generator shall be connected to the input to the telecommunications network and set for a cw signal at the desired frequency and level normally present at that frequency and location. With the meter and variable attenuator connected in series to the subscriber terminal under tests, the signal level shall be measured and recorded. Measurements shall then be made in a similar manner for all frequencies at the levels normally carried on the network.
(e) Network noise may be measured using a frequency-selective voltmeter, field strength meter which has been suitably calibrated to indicate rms noise or average power level and which has a known bandwidth. With the network operating at normal levels and with a properly matched resistive termination substituted for the antenna, noise power indications at the subscriber terminal are taken in successive increments of frequency equal to the bandwidth of the frequency-selective voltmeter, summing the power indications to obtain the total noise power present over a 4MHz band centered with the cable television channel, or equivalent noise summation technique. If an amplifier is inserted between the frequency-selective voltmeter and the subscriber terminal in order to facilitate this measurement, it should be a bandwidth of a least 4MHz and appropriate corrections must be made to account for its gain.
(f) The amplitude of discrete frequency interfering signals within a cable television channel may be determined with either a spectrum analyzer or with a frequency-selective voltmeter, field strength meter, or other suitable instruments, which instruments have been calibrated for adequate accuracy.
(g) The terminal isolation between any two terminals in the network may be measured by applying a signal of known amplitude to one and measuring the amplitude of that signal at the other terminal. The frequency of the signal should be close to the midfrequency of the channel being tested. This test is to be performed with 150 drop lead, equivalent network if desired, connected to each output spigot of the customer tap port.
(h) Radiation measurements may be made utilizing a frequency-selective voltmeter calibrated for adequate accuracy and a tuneable half-wave dipole antenna, horizontal polarized. The distance and height above ground of the measurements shall be in accordance with the Rules and Regulations of the Federal Communications Commission, Volume 11, Part 15 Subpart D, for cable television systems.
(i) The network cross-modulation measurement may be performed using a calibrated signal generator having controllable modulation, a detector and an oscilloscope. After connecting the signal generator to the lowest standard VHF frequency input terminal of the Head End signal combiner, its output shall be set for an unmodulated signal identical in frequency and level to that of the signal normally present at that point. The signals of all other channels normally carried on the network shall be fed into the combiner at their normal levels. After connecting the field strength meter to the subscriber terminus, it shall be tuned to the video carrier frequency of the channel under tests and with the oscilloscope, the modulation level may be read directly from the scope.
(j) The network hum modulation may be measured at each video carrier frequency on the network using a calibrated signal generator, a detector and an oscilloscope. The signal generator shall be connected, the level and frequency adjusted and all other channels set at their normal levels. With the detector and oscilloscopes connected to the subscriber terminus, the average level of the detected signal and the peak-to-peak A C hum will be indicated on the oscilloscope. The percent of the average level of the detected signal to one-half the indicated peak-to-peak A C hum.
(k) All actual recorded values observed as a result of the various tests shall be recorded and submitted to the City in accordance with the provisions of this section.
(1) Reverse signal capability (duplex network). The grantee shall provide in original construction a duplex network capable of reverse direction signals from each and all drops. Such carriage capability shall be at least in accordance with the requirements of the Federal Communications Commission's Third Report and Order.
(2) Maintenance. The grantee shall retain a sufficient number of technically qualified personnel to maintain the network at the quality specified. Sufficient personnel shall also be either on duty or on call during all hours of each day to maintain service at all times.
(Ord. 29-1972. Passed 3-5-73.)