Anritsu 682XXB - Manual (Page 108)

3-17
PHASE MODULATION
TESTS This procedure verifies the operation of the phase modulation ( FM) in-
put sensitivity circuits in 682XXB/683XXBs with Option 6.
The carrier level of the 682XXB/683XXB RF output is monitored on a
Spectrum Analyzer display.
FM accuracy, in both Wide and Narrow
FM modes, is determined by measuring the actual FM deviation nec-
essary to reduce the carrier level to its lowest level. These tests qualify
how the FM input signal affects the signal generator’s RF output.
Test Setup Connect the equipment, shown in Figure 3-14, as
follows:
1. Connect the 682XXB/683XXB rear panel 10 MHz
REF OUT to the Spectrum Analyzer External Ref-
erence Input.
2. Connect the RF OUTPUT of the 682XXB/683XXB
to the Spectrum Analyzer RF Input.
FM Input
Sensitivity
Procedure The following procedure lets you measure the FM
deviation for a specific input sensitivity in Wide and
Narrow
FM modes and determine FM accuracy.
3-48 682XXB/683XXB MM
PERFORMANCE PHASE
VERIFICATION MODULATION TESTS
10 MHz
REF OUT
682XXB / 683XXB
EXT REF
INPUT
RF OUT
Spectrum Analyzer
RF IN
Figure 3-14. Equipment Setup for Phase Modulation Tests