ABB ETL600 Instruction Manual page 65

ETL600
TX Filter
T3A1
d/b/z16 T3A2
T3A3
T3B1
T3B2
T3B3
T3
d/b/z14
d8
plug out
d10
TX Filter
d/b/z28
T4A1
T4A2
T4A3
T4B1
Amplifier
d/b/z30 T4B2
T4B3
Amplifier
T4
d/b/z32
common
TX Filter
d7b/z26
TX relay
z2 / b2
Amplifier alarm
z8
Fig. 3-22
Additional functions of this module:
•
Impedance matching for the Tx filter of the ETL (transformers T3
and T4)
•
Preventing of interaction with parallel ETL systems in case of
malfunction or deactivation of the own high power amplifier (relay
K1).
•
Protection of the high power amplifier against transient
overvoltages on the line
•
Supervision of the high power amplifier and alarm generation in
case of malfunction. The alarm is signaled to the P4LT module and
indicated by a LED on the front plate.
With the jumpers H1 to H6, S1 and S2, two topologies of the RF front
end can be selected:
•
Inserting jumpers H1, H2, H3, S1 selects the topology according to
Fig. 3-23a, while
•
Inserting jumpers H4, H5, H6, S2 selects the topology according to
Fig. 3-23b.
Structure and Function
1KHW001489-EN
H6
H1
H2
H4
H5
H3
hybrid
transformer
T2
RX level
R125
RD
LA
K1
CA CD
CB
Line Balancing Network
Default jumpers shown, K1 not energized
Block diagram RF hybrid P3LE
ABB Switzerland Ltd
125 Ohm
75 Ohm
operating mode 45 Ohm
S2
S1
T1
divider, frequency compensation
RA
RP
park position 45 Ohm
M1
75 Ohm
M2
R228
125 Ohm
M3
L1
LN
LP
park position
CE CL
Alarm circuit
November 2005
line output
to coax
d/b/z20
selective
supervision
z12
d12
RX RF signal
b12
RF Line Monitor
100W=0dBm
@ 50 Ohm
(50dB below line
dbz20)
K1, K2, K3,
45 75 125
Ohm Ohm Ohm
+12.8V
z6
Tx ALARM
TXRF Power Alarm
d6
GND P7LB (CE)
z10
3-33