Thomson Broadcast & Multimedia Inc. ULT-1K10K2 Benutzerhandbuch
Digital Liquid Cooled UHF
TV Equipment
Description / Test points / Location of units
9946 V1
45321648.01
104 A E
preliminary
86 / 131
Numéro / Number
Doc.
Rev.
Langu.
16/06/2006
Page
Infor
m
ati
on co
ntai
ned
is
thi
s d
o
cumen
t i
s co
nf
identi
a
l, i
s THOM
SON
pr
oper
ty
an
d ca
nno
t b
e
di
scl
ose
d
in
w
hate
ve
r for
m
wi
thout
pr
io
r wr
itten
aut
hor
iz
ati
on of
THOMSON.
3.10.5. Test
points
Connector J1 on the front of the panel provides a test monitoring
feed of the amplifier RF output signal.
feed of the amplifier RF output signal.
3.10.6. Adjustment controls
There is a potentiometer control (R164) on the front panel of each
RF amplifier module which is used to set the AGC voltage of each
power amplifier to the same value.
RF amplifier module which is used to set the AGC voltage of each
power amplifier to the same value.
3.10.7. Protection and surveillance devices
The protection card protects the amplifier using surveillance signals as follows :
♦
protection against degradation of SWR performance at the amplifier output: this surveillance device
is triggered when the SWR value is greater than 2.
is triggered when the SWR value is greater than 2.
♦
protection system against high currents in the amplifier LDMOS transistors: a fast acting current
measuring system detects an abnormal current increase in the transistors. The surveillance device
is triggered at a current I > 45 A for a block of 4 double transistors (2 amplifier modules).
measuring system detects an abnormal current increase in the transistors. The surveillance device
is triggered at a current I > 45 A for a block of 4 double transistors (2 amplifier modules).
♦
thermal protection system: when the input air temperature is greater than 60°C inside the amplifier
the amplifier is automatically switched off.
the amplifier is automatically switched off.
♦
under-voltage protection device is triggered when the DC supply drops below 24 V.
In all of the above protection systems, when a particular threshold parameter is reached, the amplifier
is protected by attenuating the input signal (by 20 dB). In case of overheating and/or overvoltage, the
amplifier is protected by an immediate shutdown by rapidly changing the transistor bias voltages.
is protected by attenuating the input signal (by 20 dB). In case of overheating and/or overvoltage, the
amplifier is protected by an immediate shutdown by rapidly changing the transistor bias voltages.
To re-start the amplifier a reset command from the Central Processing Unit is necessary.