Rohde & Schwarz M3SR Series 4100, Руководство по обслуживанию

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R&S M3SR Series 4100 HF Transceivers Function
6124.9007.82.01 1.4
1.3 Function
Refer to A1.2 - Drawings for Circuit Diagram and Interface Description.
1.3.1 Function of the R&S M3SR Series 4100 150 W HF Transceiver
The transceiver is suitable for reception in the frequency range of 10 kHz to 30 MHz and for
transmission in the frequency range of 1.5 to 30 MHz. It provides various modulation and
communication modes for voice and data. The transceiver can be locally controlled, if the optional
R&S GB 4000C Comfort Control Unit is integrated. The R&S GB 4000C is the central controller of the
transceiver. Operation and indication of the operating status are menu-oriented. Operator interaction is
performed via keyboard and display of the R&S GB 4000C. Remote control of the transceiver can be
performed via an Ethernet LAN (at X20) connected to an external Control Unit that provides the man-
machine interface. Data can be sent and received via the Ethernet port for remote control and service
purposes (configuration and software download). The Front Panel, connected to the Motherboard,
contains the microphone/headset connectors, loudspeaker and control elements for basic functions. All
other functions are handled by the R&S GB 4000C and Ethernet LAN.
The Motherboard basically provides the following functions:
¾ Distribution of the Radio Control Bus (RCB) via which the transceiver modules are controlled
¾ Control of the functional groups of the Motherboard itself, the I/O interfaces and also all other
transceiver modules by an FPGA on the Motherboard
¾ Monitoring of e.g. temperature and operating voltages by a system monitor
¾ Generation of all clock signals by the clock section which are required for the Motherboard and
the transceiver modules
¾ Distribution of power supply voltages generated by the Power Supply to the transceiver modules
and the external interfaces.
Flexible wiring is used where appropriate. Serial interfaces are used for data transfer and remote
control. Parallel interfaces are used to implement discrete inputs and outputs.
The Radio Controller provides the AF and IF signal processing and audio functions. It also controls the
internal and external RF modules and the switchover between receive and transmit mode via the Radio
Control Bus (RCB).
When the transceiver is in receive mode, the RF signal at antenna connector X30 is fed via the Power
Amplifier and connector X311 to the TX/RX input X1 of the Frontend module. In the Power Amplifier it
is filtered and preamplified. The receive signal is fed via a R&S FK 4120 / R&S FK 4140 Digital Selector
(tuneable band-pass filter) if one is connected to X313 and X314. Otherwise it is looped through
connectors X313 and X314. For a separate receiving antenna, an RX-only input X2111 is available at
the Antenna Interface which is connected to the RX input X2 of the Frontend module. In the Frontend
module the signal is downmixed to the first and the second intermediate frequency (48.048 MHz and
48 kHz). The 2nd IF signal is digitized by an A/D converter and downsampled in an FPGA. From the
Frontend output, the signal is taken via the Motherboard to the Radio Controller for further processing.