HP 70427A User Manual page 543

Overview
Figure 14-7
Procedure
Performance Tests
Test 4 - Comb line Spurs (mW LO)
Test 4 - Comb line Spurs (μW LO)
This test measures the ability of the Yig-Tuned-Filter (YTF) to reject
adjacent comb line frequencies. It does this by measuring the filter
feed-through relative to the source's output frequency. The filter
feed-through is measured at 600 MHz and 1200 MHz intervals from the
output frequency.
Specification
Spectral Purity (Configuration 3 - 600 MHz free-running oscillator):
2.4 GHz to 12.6 GHz: ................................................................. –70 dBc
13.2 GHz to 25.8 dBc: ............................................................... – 60 dBc
Equipment
HP 8562A Spectrum Analyzer
Test Setup
Comb Line Spurs Set Up Diagram
Step 1 - Set up the spectrum analyzer
You will be setting a reference level for each source output frequency in the
table. Then for each frequency you will measure the level of the spur
frequencies in dB down from the carrier (dBc).
14-32 HP 70427A/HP 70428A User's Guide