23
Configuration and setting
Technical annex
BROADBAND TERRESTRIAL TV AMPLIFIERS : The RF output levels specified in this catalogue
for IMD3=-60 dB (DIN 45004 B) are applicable when 2 analog TV channels are amplified. If, as
is usual, more than 2 TV channels are amplified, such levels have to be reduced according to
the following table:
Number of
Channels (n)
2
3
4
5
6
7
8
9
10
15
20
Output level
reduction =
7.5 · log (n-1)
dB
0
2
3.5
4,5
5
5.5
6
6.5
7
8.5
9.5
FM, DAB AND COFDM SIGNALS : If output levels of the FM, DAB and Digital TV (COFDM) signals are adjusted
10 dB or more below the levels of the analog TV channels, those signals can be ignored when calculating
the output reduction level. If referred levels are not reduced as indicated, those signals must be counted as
normal channels and the output level de-rated accordingly.
BROADBAND SATELLITE TV OR DIGITAL TERRESTRIAL TV AMPLIFIERS : The RF output levels
specified in this catalogue for IMD3=-35 dB (EN 50083-3) are applicable when 1 FM-, QPSK- or
COFDM-modulated TV channel is amplified. For a bigger number of channels, such levels have
to be reduced according to the following table:
Number of
Channels (n)
2
3
4
5
6
7
8
9
10
15
20
Output level
reduction =
10 · log n
dB
3
4.5
6
7
8
8.5
9
9.5
10
11.5
13
CASCADE REDUCTION : When m same-type broadband amplifiers are laid out in cascade, an additional
reduction of the output level equals 10 · log m must be taken into account for every amplifier.
