Rohde & Schwarz CRTU-RU Service Manual page 71

Radio Unit R&S
CRTU-RU
Contents
3 Repair ................................................................................................................... 3.1
Instrument Design and Function Description ...............................................................................3.1
Block diagram ..........................................................................................................................3.2
Instrument Frame.....................................................................................................................3.3
Rear of Instrument Frame ........................................................................................................3.3
Front of Instrument Frame .......................................................................................................3.3
Cooling the Instrument .............................................................................................................3.4
FRONT MODULE ....................................................................................................................3.5
POWER SUPPLY ....................................................................................................................3.6
MOTHERBOARD .....................................................................................................................3.7
REFERENCE BOARD .............................................................................................................3.8
Option OCXO REFERENCE OSC. CRTU-B2 .........................................................................3.9
RF FRONTEND .......................................................................................................................3.9
RXTX BOARD1/2...................................................................................................................3.10
DIGITAL BOARD....................................................................................................................3.12
Option LINKHANDLER1/2 CRTU-B5 .....................................................................................3.13
Cooling system .......................................................................................................................3.13
Control and supply..................................................................................................................3.13
Complete function ..................................................................................................................3.13
Transmitter function ...............................................................................................................3.14
Receiver function....................................................................................................................3.14
DSP 56301 Modules ..............................................................................................................3.14
DSP 56311 Modules ..............................................................................................................3.14
Option MAC SPEECH CRTU-B6 ...........................................................................................3.14
Cooling system .......................................................................................................................3.14
Control and supply..................................................................................................................3.14
MAC/RLC function..................................................................................................................3.14
Audio function.........................................................................................................................3.14
DSP 56301 Module ................................................................................................................3.15
Option IQIF BOARD CRTU-B7 ..............................................................................................3.15
Module Replacement......................................................................................................................3.17
Replacing the FRONT MODULE ...........................................................................................3.17
Opening the instrument and removing the FRONT MODULE.....................................3.17
Installing the new FRONT MODULE and completing the instrument ..........................3.18
Putting into operation ...................................................................................................3.18
Replacing the FRONT MODULE CONTROLLER in the FRONT MODULE ..........................3.19
Opening the instrument and removing the FRONT MODULE.....................................3.19
1140.0050.82 I-3.1
Contents of Chapter 3
E-4