Measurement Methods
San Diego Municipal Code § 73.0108
in effect§73.0108 Measurement Methods
(a) Signal level measurements shall be made with a properly adjusted and calibrated selective r.f. voltmeter or signal level meter or spectrum analyzer.
(b) System 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. An oscilloscope should be connected to the video output of the field strength meter to insure that any peaks that may be noted are not caused by a spurious frequency or cross modulation interference problem. With the system 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 4.0 MHz band centered within the cable television channel. If it is established that the noise level is constant within this bandwidth, a single measurement may be taken which is corrected by an appropriate factor representing the ratio of 4.0 MHz to the noise bandwidth of the frequency selective voltmeter. If an amplifier is inserted between the frequency–selective voltmeter and the subscriber terminal in order to facilitate this measurement, it should have a bandwidth of at least 4.0 MHz and appropriate corrections must be made to account for its gain and noise figures. Alternatively, measurements made in accordance with the NCTA standard on noise measurement (NCTA Standard 005–0669) may be employed.
(c) When deemed necessary by the City Manager, cross modulation shall be measured as follows:
Method 1. A block diagram of the setup for this test is on file in the office of the City Clerk as Document No. 732488. Normal picture and sound input signals (including FM signals where carried) are supplied to each channel to be carried except the channel under observation; a CW signal is supplied to the viewing channel at white level. No cross–modulation products (“wind-shield-wiper” effects) should be visible on a monitor receiver located at an appropriate test drop, at an ambient temperature of 32 degrees Fahrenheit or above.
(d) Spurious signals may be detected and identified with a spectrum analyzer or other suitable instruments.
(Amended 4–6–1981 by O–15480 N.S.)
(Editors note: Title added 8–9–1988.)
Source: City of San Diego Office of the City Clerk, San Diego Municipal Code and City Charter (docs.sandiego.gov PDFs)URL: https://docs.sandiego.gov/municode/MuniCodeChapter07/Ch07Art03Division01.pdf#page=9Fetched: 10/28/2026