Specifications
ZVx Selftest
1043.0009.50 4.5 E-3
4.3.1.5 Local
The Local module provides the LO signals for the two mixers in the front end channels (LO1 signal for
the 1st mixer, LO2 signal for the 2nd mixer). In addition, it contains the reference frequency source from
which it generates the reference signal for the synthesizers (Synthesizer modules) and the signal for
generation of the sampling signals in the converter modules.
• The LO1 signal is derived from the local synthesizer signal by frequency doubling, direct use and
frequency division.
• The LO2 signal is generated from a synthesizer from 200 MHz to 210 MHz and by means of
frequency division by 10.
4.3.1.6 Source
The source module delivers the generator signal (frequency range 10 Hz to 4 GHz). This signal is
amplified in the output stage and applied to the DUT. The source synthesizer signal (0.989 GHz to 2
GHz) is processed by means of frequency doubling, direct use, mixing and frequency division. For
frequencies below 2 MHz, the generator level control is performed in the source module (for the
frequency range >2 MHz, in the output stage module with level detector in the SWR bridges).
4.3.1.7 Output Stage
The output stage amplifies the signals RFLOW (10 Hz to 10 MHz) and RFHIGH (10 MHz and 4 GHz)
coming from the source module to the given nominal output level. For this purpose, it comprises an
amplifier and a level control, for the ZVC-models in addition a frequency doubler. The associated level
detectors are accommodated on the source module (frequency range 10 Hz to 2 MHz) or in the SWR
bridges in the test set (frequency range >2 MHz). For the range 10 Hz to 150 MHz, the control element is
also to be found on the source module, for the range > 150 MHz, it is located on the high-band amplifier
of the output stage.
4.3.2 Modules of the Digital Unit
The digital unit consists of the following modules:
• Main processor
• Graphics board
• I/O board (contains the interface drivers such as IEC bus, LPT and COM)
• Hard disk
• Floppy disk
• LC display
• Keyboard
• VGA card (option controller function)
• 2
nd
IEC bus (option for option controller function)
• LAN interface (option)