Manual Test Procedure
R&S SM300
Version 04
74
Service Manual SM300: 1147.1652.00
Instrument Part No SM300: 1147.1498.03
Measurement
Read the level on the test receiver or analyzer and note down as a
reference value. It should be ideally 10 dBm minus 125 dB attenuation
equal to -115 dBm. Select measurement bandwidth of a small value to
obtain an accurate reading.
The deviation from the reference value shown on analyzer display is the
level error.
Measurement at levels < -115 dBm
Caution
A prerequisite for correct measurements is that the components used are
completely RF-shielded
Test setup
Switch a low-noise preamplifier between SM300 and precision attenuator.
Measurement
Perform a calibration at a measured level.
It is thus possible to measure levels down to the lower limit of SM300
Level on SM300
Attenuation of attenuator
Reference level
125 dB
Reference level -5 dB
120 dB
Reference level -10 dB
115 dB
Reference level -20 dB
105 dB
Reference level -40 dB
85 dB
Reference level -60 dB
65 dB
Reference level -80 dB
45 dB
Reference level -100 dB
25 dB
Reference level -120 dB
5 dB
Reference level -125 dB
0 dB
Table 2-2: Test level 2 Level accuracy
