Operating instructions

46882-311D 4-1
Chapter 4
TECHNICAL DESCRIPTION
Contents
Overview........................................................................................................................................ 4-2
Power supply .......................................................................................................................... 4-2
The display ............................................................................................................................. 4-3
Tx test mode .................................................................................................................................. 4-7
Modulation sources................................................................................................................. 4-7
Audio generators ............................................................................................................. 4-7
Data generator ................................................................................................................. 4-8
Receiver circuits ..................................................................................................................... 4-9
Input switching................................................................................................................ 4-9
Broad band power meter.................................................................................................. 4-9
Overload detection......................................................................................................... 4-10
Switched attenuator ....................................................................................................... 4-10
IF circuits.............................................................................................................................. 4-10
First frequency changer/mixer....................................................................................... 4-10
First local oscillator ....................................................................................................... 4-10
Second frequency changer/mixer................................................................................... 4-10
Second local oscillator................................................................................................... 4-10
Third frequency changer/mixer...................................................................................... 4-11
Bandwidth filters ........................................................................................................... 4-11
Demodulators........................................................................................................................ 4-11
AM demodulator ........................................................................................................... 4-11
FM demodulator ............................................................................................................ 4-11
SSB demodulator (optional) .......................................................................................... 4-11
De-emphasis filter.......................................................................................................... 4-12
RF counter ............................................................................................................................ 4-12
Measurement ranging circuits............................................................................................... 4-12
Distortion/SINAD filter........................................................................................................ 4-12
Oscilloscope function ...........................................................................................................4-12
Rx test mode ................................................................................................................................ 4-12
RF generator ......................................................................................................................... 4-13
Modulators............................................................................................................................ 4-13
RF amplifier.......................................................................................................................... 4-13
Audio generators................................................................................................................... 4-13
Modulation control ............................................................................................................... 4-13
Pre-emphasis filter................................................................................................................ 4-14
AF measuring circuits...........................................................................................................4-14
Oscilloscope function ...........................................................................................................4-14
Dx test mode................................................................................................................................ 4-14
Spectrum analyzer mode.............................................................................................................. 4-14
Look and listen function ....................................................................................................... 4-14
AF test mode................................................................................................................................ 4-15
Systems mode .............................................................................................................................. 4-15
List of figures
Fig. 4-1 Block diagram of power supply module......................................................................... 4-2
Fig. 4-2 Simplified block diagram ............................................................................................... 4-5
Fig. 4-3 AF generator detailed block diagram ............................................................................. 4-7
Fig. 4-4 Input switching and broad band power meter block diagram......................................... 4-9