16
UK
■
RF LEVEL ADJUSTMENT
1.
Remove the coaxial bridge
from the RF channel
output (8) of
module 1
beside the power source.
2.
Adjust the output level to 75 dB
μ
V
via UCF 100
(see point 2 Programming).
3.
Connect
the 75
Ω
axial bridge
again
.
4.
Taking the measurement at the
SHA or SAC amplifier
output
, adjust the levels of the other modules so that
they are
equalised to the level of module 1
,
which has already been adjusted.
5.
Adjust the amplifier gain, taking into account its
maximum output level and the
reduction
according
to the
number of the channels
in the installation,
as shown in Table 1.
Tab. 1
■
LED FUNCTIONS
●
Status LED:
●
Green
color: Tuner tuned
●
Yellow
color: Signal problems
– Unsyncronized tuner.
– Program not found.
– Exceeded output BW > 92%.
– Out RF: OFF.
●
Red
color: Unit failure
●
Communication LED:
Yelow: waiting for data.
■
FAQs:
●
How many programs fit on an RF, COFDM, UHF,
8 MHz channel?
The channel’s output capacity is measured in MBs and
there is a direct relationship between the following:
●
Modulation
: QPSK < 16 QAM <
64 QAM
●
Code Rate
FEC:1/2 < 2/3 < 3/4 < 5/6 <
7/8
●
Save interval
IG: 1/4 < 1/8 < 1/16 <
1/32
(maximum capacity shown in
bold
).
●
The number of programs depends on the amount
of information contained in each one.
Number of
2 4 5 6 8 16 24 32 64
channels COFDM
Reduction of the
maximum output
3 6 7 8 9 12 16 15 18
level (dB)
DVB-T (8MHz)
Bitrate (Mbps)
Modulation Code Rate Tu = 1/4 Tu = 1/8 Tu = 1/16 Tu = 1/32
1/2
4,98
5,53
5,85
6,03
2/3
6,64
7,37
7,81
8,04
QPSK
3/4
7,46
8,29
8,78
9,05
5/6
8,29
9,22
9,76
10,05
7/8
8,71
9,68
10,25
10,56
1/2
9,95
11,06
11,71
12,06
2/3
13,27
14,75
15,61
16,09
16 QAM
3/4
14,93
16,59
17,56
18,10
5/6
16,59
18,43
19,52
20,11
7/8
17,42
19,35
20,49
21,11
1/2
14,93
16,59
17,56
18,10
2/3
19,91
22,12
23,42
24,13
64 QAM
3/4
22,39
24,88
26,35
27,14
5/6
24,88
27,65
29,27
30,16
7/8
26,13
29,03
30,74
31,67
Summary of Contents for SCT 8000
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