Calibration—492/492P Service Vol. 1 (SN B030000 & up)
Performance Check
d. Slowly tune the frequency of the signal generator
across the 100 kHz to 10 MHz span, monitoring the output
with the power meter to ensure a constant input signal level,
and note amplitude variations. Response or variations must
not deviate more than ± 1.5 dB from the mean.
e. Remove the 10 kHz to 10 MHz signal source and con
nect the output of a 0.01 to 2.4 GHz generator to the RF
INPUT (see Fig. 3-5). The output of the sweep generator is
applied through a 3 dB attenuator and a semi-rigid high per
formance coaxial cable to a power divider. Connect one out
put of the power divider directly to the 492/492P RF INPUT
and the other to the power sensor unit for the power meter.
Ensure that all connections are snug.
f. With the FREQ SPAN/DIV at 200 MHz, tune the FRE
QUENCY to approximately 1.0 GHz. Adjust the generator
cw frequency to 1.0 GHz and adjust the output for — 6 dBm
reading on the power meter.
h. Set the sweep generator span so it sweeps from 0.01
to 2.2 GHz. Set the generator sweep mode for automatic
internal sweep at its slowest sweep time (100 s). Monitor
the power output as the generator sweeps across the span
to ensure that the output remains constant. The frequency
response (deviation from the mean) must not exceed
±1.5 dB. A typical response for the frequency range of 3.6
to 5.6 GHz is shown in Fig. 3-6.
NOTE
If any part of the span is not within specification, tune
to the center of the respective section and decrease
the FREQ SPAN/DIV to display that portion. De
crease the sweep o f the sweep oscillator accordingly
and check flatness for the narrower portion. It may be
necessary to tune the center frequency across the re
spective span in small increments, measuring re
sponse at each point to verify response flatness.
g. With the Vertical Display at 2 dB/DIV, adjust the REF i. Increase the FREQUENCY RANGE to band 2
LEVEL so the amplitude of the signal is about half screen. (1.7—5.5 GHz). Tune the FREQUENCY to approximately
492 Spectrum Analyzer
Signal Source (10 KHz-10 MHz)
O
50 Ohm Output
:o
7
ϋ
N to BNC Adapter
2 7 2 7 - 2 4A
Fig. 3-4. Test equipment setup for checking the 10 kHz—10 MHz frequency response.
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