Rohde & Schwarz R&S SMU200A, Service Manual

Page: 37 / 294

Test Procedures R&S SMU200A
1007.9845.82 1.10
E-12
Frequency
Frequency Setting
Test equipment Frequency counter (Table 1-2, item 1)
Test method The frequency setting is checked using a frequency counter whose
reference frequency is in sync with that of the DUT.
Measurement
Setting on DUT:
- Frequency : test frequency unmodulated, recommended
frequencies: according to Table 1-4
-
Level : 0 dBm
The measured values must be exactly within the framework of the
counter resolution.
Settling Time
Test assembly
See section "
Test Assembly for Settling Time
", page 1.5 . For measuring
after IEC/IEEE bus delimiter the EOI-line of the IEC/IEEE bus is used as
trigger signal instead of the pulse generator.
Test method The spectrum analyzer is operated as an FM demodulator. A controller
transmits the start and the stop frequency via the IEC/IEEE bus. The
analyzer is triggered by the positive edge on the EOI line of the IEC/IEEE
bus or the trigger pulse in list mode. At switch over from start to stop
frequency, the settling procedure is displayed on the screen of the
analyzer.
Preparation of measurement Synchronize the reference frequencies of the DUT and the analyzer.
Make IEC/IEEE bus and RF connections.
Connect trigger connector to EOI line (pin 5) of IEC/IEEE bus.
Settings on DUT:
- Frequency : start frequency unmodulated,
- Level : 0 dBm
Settings on spectrum analyzer:
- AMPT/REF LEVEL 0 dBm
- FREQ/CENTER/STOP FREQUENCY
- FM DEMOD ON
- DEMOD BW 100 kHz
- RANGE /DEVIATION PER DIV 200 Hz
- MEAS TIME 5 ms, 10 ms with ALC State Off
Measurement Settings on analyzer: TRIGGER EXTERN
- External triggering by positive edge at 1.4 V.
Send the stop frequency from the controller.
The settling curve is displayed on the screen of the externally
triggered analyzer. The time for reaching the specified deviation can
be determined by using the cursor.
Repeat the measurement with the start and the stop frequency inter-
changed.