Aurora Multimedia V-Tune Pro VPH-100, Руководство пользователя

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15
Maximum amplitude variation across the 6-MHz channel (analog channels) < 5 dB p-
p ≤ 4 dB p-p
13. Micro-reflections bound for dominant echo
-10 dB at < 0.5 µs
-15 dB at < 1.0 µs
-20 dB at < 1.5 µs
-30 dB at < 4.5 µs
Micro-reflections longer than 4.5 microseconds rarely occur in conventional cable television systems. Moreover very
low-level micro-reflections (e.g., -40dB) longer than 4.5 microseconds may not be measured reliably. Therefore,
micro-reflections longer than 4.5 microseconds shall be considered under item 4 (of this table) as a contributor to
C/(N+I)
14. Burst Noise Not longer than 25 µs at 10-Hz repetition rate
15. Carrier level at the terminal input
64 QAM: -15 dBmV to + 15 dBmV
256 QAM: -12 dBmV to +15 dBmV
Analog Visual Carrier (c):
0 dBmV to +15 dBmV
Analog Aural Carrier:
-10 dBc to
–17 dBc
Nominal Relative Carrier Power Levels
Analog channel 0 dBc (reference level)
QAM FAT -5 ± 2 dBc
QPSK FDC -8 ± 5 dBc
QAM FAT -10 ± 2 dBc