Thales 421 - Fig. 6−7 Preparation and Adjustments During a Subassembly Replacement

LLZ 421
Operation and Maintenance Repair
ILS 420
6−33Ed. 01.10
SOAC
Unit to be changed Preparation (see also Fig. 6−6) Adjustments after change
SYN
MODPA LLZ
MODPA GP
INTFC
LG−A
LG−M
ECU
Stby and On−Air Com-
biner (SOAC)
PIN−Diode Transfer
Switch
GP only:
− Power Adder
LCP (complete)
Modem LGM28.8
Modem LGM 1200MD
VAM (optional)
DCC−MV
LVS/DCC−5
TX1/TX2 switch panel
ACC−54
remove RF cables at front side
remove RF cables at front side
use handle to withdraw
remove RF cables at front side
use handle to withdraw
−
−
−
−
hinge down board, remove
cables rear side, hinge up board
and fix it; support the board,
loosen 2 screws left and right
remove cables, support the board
with the handles and loosen 2
screws left and right
remove RF cables
remove cables, loosen 5 screws
loosen screw (if in plastic cover)
loosen screw (if in plastic cover)
−
loosen 2 screws on front panel,
use handle to withdraw
remove cables, loosen 4 screws,
withdraw board from BP−PS
loosen 4 screws, remove cables
loosen 2 screws on front panel
Adjust station frequency
check RF level, modulation depths, phasing
regard location of MODPA GP: check cor-
rect jumper setting of upper RF path.
check RF level, modulation depths, phasing
Change of INTFC 120498 against 120628:
(!) calibrate and normalise monitor
(!) load LG−A firmware (see 6.6.3.4);
load all transmitter data; the location of the
LG−A (TX1 or TX2) must be regarded.
readjustment of transmitter necessary
(!) load LG−M firmware (see 6.6.3.4);
load all monitor data; the location of the
LG−M (TX1 or TX2) must be regarded.
readjustment of transmitter necessary
Check setting of switch bank SW1. It must
correspond to the software configuration
setting !
(!) calibrate detector paths
(!) calibrate monitor
(!) readjust for standby transmitter
check RF level, modulation depths, phasing
check RF level, modulation depths, phasing
(!) calibrate monitor
Configure to system (see 6.6.3.4);
re−load installation type, configuration, site
and PTT file
−
−
−
−
−
−
If need be, adjust charging voltage (R32)
Fig. 6−7 Preparation and adjustments during a subassembly replacement