110 lines
5.4 KiB
Plaintext
110 lines
5.4 KiB
Plaintext
Cable Frequencies
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by THE RESEARCHER
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I have been doing a lot of research in recent months on television
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signals in terms of both radio frequency and video after demodulation. A lot
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of facinating components make up a color television signal. If the signal has
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been scrambled to prevent unauthorized reception, it is even more intriguing.
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I have examined the signals of two cable companies in West Virginia who
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employ scrambling techniques and find that no actual scrambling is being done.
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That is, the signals are not "mixed up" in any way. All that has been done is
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the horizontal sync and blanking pulses have been suppressed about 6 db below
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the peak video level. Except for that modification all the signal components
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are intact and in proper sequence. The scrambling occurs inside the TV
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receiver because of its inability to locate and lock on to the horizontal sync
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pulses.
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If you are interested in this kind of experimenting, an excellent series
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of articles began in the June 1986 issue of "Radio Electronics" and is
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continuing as of this date (August 1986). It may also be of value to know
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where the signals you want to work on are located in terms of frequency. If
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you have ever wondered where those mid band and super band cable channels are
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located, the following table will be enlightening.
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Table of CATV Channels VS. Frequency in MHz
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---------------------------------------------
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! Channel ! ! Video ! Audio !
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! Number ! Bandwidth ! Carrier ! Carrier !
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!---------------------------------------------!
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! T7 ! 5.75- 11.75! 7.0 ! 11.5 !
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! T8 ! 11.75- 17.75! 13.0 ! 17.5 !
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! T9 ! 17.75- 23.75! 19.0 ! 23.5 !
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! T10 ! 23.75- 29.75! 25.0 ! 29.5 !
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!---------------------------------------------!
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! TV-IF ! 40.0 - 46.0 ! 41.25 ! 45.75 !
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!---------------------------------------------!
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! 2 ! 54.0 - 60.0 ! 55.25 ! 59.75 !
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! 3 ! 60.0 - 66.0 ! 61.25 ! 65.75 !
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! 4 ! 66.0 - 72.0 ! 67.25 ! 71.75 !
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! 5 ! 76.0 - 82.0 ! 77.25 ! 81.75 !
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! 6 ! 82.0 - 88.0 ! 83.25 ! 87.75 !
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!---------------------------------------------!
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! FM Radio! 88.0 - 108.0 ! ! !
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!---------------------------------------------!
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! A-2 ! 108.0 - 114.0 ! 109.25 ! 113.75 !
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! A-1 ! 114.0 - 120.0 ! 115.25 ! 119.75 !
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! A (14) ! 120.0 - 126.0 ! 121.25 ! 125.75 !
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! B (15) ! 126.0 - 132.0 ! 127.25 ! 131.75 !
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! C (16) ! 132.0 - 138.0 ! 133.25 ! 137.75 !
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! D (17) ! 138.0 - 144.0 ! 139.25 ! 143.75 !
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! E ! 144.0 - 150.0 ! 145.25 ! 149.75 !
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! F (19) ! 150.0 - 156.0 ! 151.25 ! 155.75 !
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! G (20) ! 156.0 - 162.0 ! 157.25 ! 161.75 !
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! H (21) ! 162.0 - 168.0 ! 163.25 ! 167.75 !
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! I (22) ! 168.0 - 174.0 ! 169.25 ! 173.75 !
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!---------------------------------------------!
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! 7 ! 174.0 - 180.0 ! 175.25 ! 179.75 !
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! 8 ! 180.0 - 186.0 ! 181.25 ! 185.75 !
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! 9 ! 186.0 - 192.0 ! 187.25 ! 191.75 !
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! 10 ! 192.0 - 198.0 ! 193.25 ! 197.75 !
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! 11 ! 198.0 - 204.0 ! 199.25 ! 203.75 !
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! 12 ! 204.0 - 210.0 ! 205.25 ! 209.75 !
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! 13 ! 210.0 - 216.0 ! 211.25 ! 215.75 !
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!---------------------------------------------!
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! J (23) ! 216.0 - 222.0 ! 217.25 ! 221.75 !
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! K ! 222.0 - 228.0 ! 223.25 ! 227.75 !
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! L ! 228.0 - 234.0 ! 229.25 ! 233.75 !
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! M ! 234.0 - 240.0 ! 235.25 ! 239.75 !
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! N ! 240.0 - 246.0 ! 241.25 ! 245.75 !
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! O ! 246.0 - 252.0 ! 247.25 ! 251.75 !
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! P ! 252.0 - 258.0 ! 253.25 ! 257.75 !
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! Q ! 258.0 - 264.0 ! 259.25 ! 263.75 !
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! R ! 264.0 - 270.0 ! 265.25 ! 269.75 !
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! S ! 270.0 - 276.0 ! 271.25 ! 275.75 !
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! T ! 276.0 - 282.0 ! 277.25 ! 281.75 !
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! U ! 282.0 - 288.0 ! 283.25 ! 287.75 !
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! V ! 288.0 - 294.0 ! 289.25 ! 293.75 !
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! W ! 294.0 - 300.0 ! 295.25 ! 299.75 !
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!---------------------------------------------!
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! AA ! 300.0 - 306.0 ! 301.25 ! 305.75 !
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! BB ! 306.0 - 312.0 ! 307.25 ! 311.75 !
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! CC ! 312.0 - 318.0 ! 313.25 ! 317.75 !
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! DD ! 318.0 - 324.0 ! 319.25 ! 323.75 !
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! EE ! 324.0 - 330.0 ! 325.25 ! 329.75 !
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! FF ! 330.0 - 336.0 ! 331.25 ! 335.75 !
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! GG ! 336.0 - 342.0 ! 337.25 ! 341.75 !
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! HH ! 342.0 - 348.0 ! 343.25 ! 347.75 !
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! II ! 348.0 - 354.0 ! 349.25 ! 353.75 !
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! JJ ! 354.0 - 360.0 ! 355.25 ! 359.75 !
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! KK ! 360.0 - 366.0 ! 361.25 ! 365.75 !
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! LL ! 366.0 - 372.0 ! 367.25 ! 371.75 !
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! MM ! 372.0 - 378.0 ! 373.25 ! 377.75 !
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! NN ! 378.0 - 384.0 ! 379.25 ! 383.75 !
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! OO ! 384.0 - 390.0 ! 385.25 ! 389.75 !
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! PP ! 390.0 - 396.0 ! 391.25 ! 395.75 !
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! QQ ! 396.0 - 402.0 ! 397.25 ! 401.75 !
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! RR ! 402.0 - 408.0 ! 403.25 ! 407.75 !
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! SS ! 408.0 - 414.0 ! 409.25 ! 413.75 !
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! TT ! 414.0 - 420.0 ! 415.25 ! 419.75 !
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! UU ! 420.0 - 426.0 ! 421.25 ! 425.75 !
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! VV ! 426.0 - 432.0 ! 427.25 ! 431.75 !
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! WW ! 432.0 - 438.0 ! 433.25 ! 437.75 !
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! XX ! 438.0 - 444.0 ! 439.25 ! 443.75 !
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! YY ! 444.0 - 450.0 ! 445.25 ! 449.75 !
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! ZZ ! 450.0 - 456.0 ! 451.25 ! 455.75 !
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---------------------------------------------
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The numbers in parentheses are the channel numbers assigned by Capitol
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Cablevision in Charleston, WV to their upper tier channels.
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DOWNLOADED FROM AND ORIGINALY DISPLAYED ON P-80 SYSTEMS....
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