Rohde & Schwarz 1164.4391.03, Service Manual

Page: 45 / 254

R&S FSP Performance Test
116
4
.4556.82 1.17 E-1
Checking Reference Level Switching (IF Gain)
Test principle: The IF gain of the R&S FSP can be switched from 0 to 50 dB by
changing the reference level at fixed RF attenuation. To prevent the IF
gain accuracy from being confused with the log amplifier accuracy, it
is determined by comparison using an external precision attenuator.
Test equipment:
-
Signal generator (refer to "Measurement Equipment", item 3)
Frequency 128 MHz
Maximum level -10 dBm
-
Step attenuator (refer to "Measurement Equipment", item 11)
Frequency 128 MHz
Attenuation 0 to 60 dB in 1 dB steps
Attenuation accuracy < 0.1 dB
1
)
1
) If a step attenuator with lower accuracy is used, correction
of the measured attenuation is recommended.
Test setup: Connect RF output of the signal generator to RF input of the step
attenuator.
Connect RF output of the step attenuator to RF input of the
R&S FSP.
Signal generator settings: - Frequency 128 MHz
- Level -10 dBm
Step attenuator settings: Attenuation 20 dB
R&S FSP settings: - [ PRESET ]
- [ FREQ : CENTER : 128 MHz ]
- [ SPAN : 2 kHz ]
- [ BW : RES BW MANUAL : 1 kHz ]
- [ BW : VIDEO BW MANUAL : 100 Hz ]
- [ TRACE : DETECTOR : RMS ]
- [ AMPT : RF ATTEN MANUAL : 10 dB ]
- [ AMPT : - 10 dBm ]
Reference measurement: Set marker to peak of signal:
- [ MKR : PEAK ]
Set reference to peak of signal:
- [ MKR : REFERENCE FIXED ]