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R & S E K 8 9 5 / R & S E K 8 9 6
User Manual
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IF Converter R&S UX 895 (Option)
1.3.13 IF Converter R&S UX 895 (Option)
1.3.13.1 Design
The IF Converter UX 895 consists of a printed
circuit board and the interfaces to the IF / AF
signal processor.
1.3.13.2 Functioning
(See Fig. 1.17)
The IFIN signal from the IF / AF processor is fed,
depending on signal OPT2, either via switch S1
to a line driver or via switch S2 to a converter
stage.
If switch S1 is closed, the IFIN signal (0 to
40!kHz) is routed unchanged to the line driver.
If switch S2 is closed, the converter stage con>
verts the IFIN signal (20.218 kHz) into the inter>
mediate frequency of 455 kHz with the aid of
an auxiliary frequency.
The auxiliary frequency is obtained from the
20>MHz fixed frequency of the IF / AF processor
and via a 46:1 divider. The following amplifier
provides for adaptation to the input imped>
ance of the ceramic filter. The filter suppresses
the auxiliary frequency as well as unwanted
mixing products. The ceramic filter is followed
by the line driver.
The low>impedance signal of the line driver is
in addition rectified and evaluated in the built>
in equipment test as BIT signal.
Fig. 1.17 IF Converter R&S UX 895 (Option), Block Diagram
IF = 455 kHz
S1
S2
y
OPT2
OPT2
1
46
BIT
IFOUT
IFIN
20 MHz
6164.0717.02_01
> 1.30 >
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