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Published byTamsyn Fleming Modified over 9 years ago
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1 Campus Cable TV Signal Leakage: What’s The Story, and What Should We Be Doing About It?
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2 Disclaimer: The opinions expressed by the presenter during this presentation do not necessarily reflect those of The Georgia Institute of Technology, Campus Televideo, The Association of Higher Education Campus Television Administrators, or the Peabody Hotel. (But they should.)
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3 Signal Leakage: Types Don’t use the “R” word. (Radiation) Ingress: Unwanted RF signals getting INTO the Cable System. Egress: Unwanted RF signals getting OUT of the Cable System.
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4 Signal Ingress: RF signals outside the cable at or near the same frequency of the RF signals on the cable will cause problems with the RF signals on the cable if they can get in. AnalogDigital
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5 Cable TV Shares the Spectrum With Off-Air
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6 Signal Egress: Channels 95 through 22 added in the 1970’s
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7 Signal Egress: Air Distress Frequency (121.5 MHz) 1984 FCC begins Signal Leakage Monitoring Requirements for Franchised Cable TV Systems Frequency offsets added in 1989.
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8 Signal Leakage: (CLI) Cumulative Leakage Index FCC begins CLI in the 1990’s.
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9 Signal Leakage: Cumulative Leakage Index What does this have to do with Me?
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10 Signal Leakage: Cumulative Leakage Index
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11 Signal Leakage: Cumulative Leakage Index (MVPD=Multichannel Video Programming Distributor)
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12 Signal Leakage: Cumulative Leakage Index
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13 Signal Leakage: Cumulative Leakage Index So what does this mean?
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14 Signal Leakage: Cumulative Leakage Index CFR 47 Part 76, 76.605(a)(12), 76.610-76.614, 76.616, 76.617, 76.1706, 76.1803, 76.1804 Prior to the use of signals in the aeronautical radio bands, and at least once each calendar year, CATV systems, MVPDs, and Non-Cable MVPDs must comply with FCC requirements for signal egress.
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15 Aeronautical Frequencies 108 MHz137 MHz 225 MHz400 MHz Channels 98, 99, 14, 15, & 16 Channels 24 thru 53
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16 Aeronautical Frequencies CFR 47 76.616 (b)…”The transmission of digital signals in this range is limited to power levels measured using a root-means-square detector of less than 10 -5 watts (+34 dBmV) in any 30 kHz bandwidth over any 2.5 millisecond interval.”
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17 Signal Leakage: Cumulative Leakage Index What do I need to do?
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18 Signal Leakage: Cumulative Leakage Index If you are going to use the aeronautical channels… Consult with your Legal department. Get FCC forms 320 & 321 in order. (More on this later)
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19 Signal Leakage: Cumulative Leakage Index If you are already using the aeronautical channels… Consult with your Legal department. Get FCC forms 320 & 321 in order. (More on this later)
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20 Signal Leakage: Cumulative Leakage Index Acquire Commercial Signal Leakage detection equipment. (Make a “calibrated leak”.) FM Radio Contracted Fly-Over or Ride-Out
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21 Signal Leakage: Cumulative Leakage Index At least 75% of the oldest part of the cable system needs to be tested every year. All Signal Leaks measured at more than 20 micro/V per meter @ 3 meters (10 feet) must be repaired. All Signal leaks measured at greater than 50 micro/V per meter @ 3 meters must be logged for CLI calculation.
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22 Calculating CLI
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23 Calculating CLI
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24 Egress: Where does Egress come from?
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25 Signal Leakage: Egress: How does it get out? A lack of proper System Maintenance.
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26 Signal Leakage: Egress: How does it get out? Loose or improperly made connectors.
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27 Signal Leakage: Egress: How does it get out? Cracks in the Cable Shield. How old is your mainline coax? (Coax older than 15 years is very prone to shield defects.)
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28 Signal Leakage: Egress: How does it get out? Attempted signal theft. Roughly 75% of all cable signal leakage occurs between the Tap and the Television.
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29 In case you’re Wondering….. “What if I don’t comply?” (aka: “I’ll take my chances.”)
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30 Reminder…
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31 Q & A
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32 Penalties
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33 The Bottom Line… File it. (FCC Form 321) Find it. Fix it. Report it. (FCC Form 320)
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34 Questions?
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