Rohde & Schwarz M3SR Series 4100, Service Manual, Page: 60 / 138

R&S M3SR Series 4100 HF Transceivers Front Panel - Function
6124.9007.82.01 1.24
1.3.2.8 Front Panel - Function
The Front Panel is equipped with operating buttons, connectors, LEDs and loudspeaker (see
Fig. 1.10).
The Front Panel is connected to the Motherboard via connector X2 (see Fig. 1.11). All inputs and out-
puts of the Front Panel are proof against short cuts and static voltages from outside. Behind the two
inputs for the microphones a two stage amplifier and a dynamic compressor are arranged.
To the connector X5 a Fill Gun Device can be connected. By using the RS232 interface the needed
data can be loaded into the radio. The DC voltage for the Fill Gun will be delivered from the radio to the
Fill Gun via X5 pin 20. So the Fill Gun does not need any further external supply voltage. The battery
line is protected with fuse F1 (1 A) located on the printed circuit board.
The special temperature monitoring integrated circuit transmits the actual temperature of the printed
circuit board via an I
2
C Bus to the Motherboard.
The integrated regulator circuits generate operating voltages of ±10.5 VDC and +5 VDC for onboard
components.