FTE Maximal HCA 2210/RC Manual De Instrucciones página 11

BCN
headend
Output Level
Amplified channels list and output level reduction
K 0 10
0 ... 6,99
1 ... 7,40
2 0,00 7,78
3 1,76 8,13
4 3,01 8,45
5 3,98 8,75
6 4,77 9,03
7 5,44 9,29
8 6,02 9,54
9 6,53 9,78
For example: 36 channels mean a reduction of 12,55 dB.
To calculate the reduction of number of channels must keep in mind all TV channels and also radio
ones (FM). In case that radio channels have a level 10 dB lower than TV ones, will not be calculated
in the output level reduction.
Usually out level is measured for an intermodulation of 3rd order of -60 dB (IMA3 -60 dB). To get
that intermodulation level at the output is in -72 dB, 6 dB extra of output level reduction must be
applied. There are measure norms that apply other intermodulation levels, for example norm 1R8-
15 applies an intermodulation of 3rd order of -72 dB and an intermodulation of 2nd order of -69 dB.
Must be kept in mind an added reduction according to the number of amplifiers that are in cascade,
in this way, if the first is the one that amplifies the cascade its output level must be reduced in -3
dB, if it is the second -6 dB and if it is the third, -9 dB.
Example 1:
CATV with TV and radio (FM) channels. Measured acording 1R8-15
Total: 34 TV channels and 29 radio channels with same level.
The maximum output level for HCA 2210:
114 dBµV – 15 dB (63 channels reduction) – 6 dB (IMA 72dB) = 93dBµV
Example 2:
CATV with TV and radio (FM) channels.
TV: 48 channels and 24 radio channels distributed. Radio channels with 10 dB less than TV channels.
The maximum output level for HCA 2210:
114 dBµV – 14 dB (48 channels reduction) = 100 dBµV
Example 3:
Cascade re-amplification for 36 TV channels and 24 radio channels (-10 dB). First re-amplification:
The maximum output level for HCA 2210 acording 1R8-15 is:
114 dBµV – 12,5 dB (36 channels reduction) – 6 dB (IMA 72dB) – 3 dB (cascade) = 92,5dB
20 30 40
10,00 11,76 13,01 13,98 14,77 15,44 16,02 16,53
10,21 11,90 13,12 14,07 14,84 15,50 16,07 16,58
10,41 12,04 13,22 14,15 14,91 15,56 16,13 16,63
10,61 12,17 13,32 14,23 14,98 15,62 16,18 16,67
10,79 12,30 13,42 14,31 15,05 15,68 16,23 16,72
10,97 12,43 13,52 14,39 15,12 15,74 16,28 16,77
11,14 12,55 13,62 14,47 15,19 15,80 16,33 16,81
11,30 12,67 13,71 14,55 15,25 15,85 16,38 16,86
11,46 12,79 13,80 14,62 15,31 15,91 16,43 16,90
11,61 12,90 13,89 14,70 15,38 15,97 16,48 16,95
HCA 2210/RC
50 60 70 80 90
11