HP 8559A - 4-13. Residual FM

PERFORMANCE TESTS
MODEL
8559A
PERFORMANCE TESTS
4 - 13. RESIDUAL FM
SPECIFICATION:
Less than 2 kHz peak
- to - peak for a time interval 10.1 second; less than 2 kHz peak - to - peak in a 180 - series
display mainframe with
220/240 line voltage.
DESCRIPTION:
This test measures the inherent short
- term instability (residual FM) of the LO system in the spectrum analyzer.
A stable signal (supplied by a comb generator) is applied to the spectrum analyzer input and slope
- detected with
the linear portion of the 10
- kHz bandwidth filter in zero span (fixed - tuned receiver - see Figure 4 - 6). Variations
of the spectrum analyzer's LO frequency (residual FM) can be measured as an amplitude shift on the CRT
display (1 kHz
= 0.7 major division with LIN Amplitude Scale).
SPECTRUM
ANALYZER
COMB
GENERATOR
ADAPTER
P P
ADAPTER
FIGURE 4-5.
RESIDUAL FM TEST SETUP
EQUIPMENT:
Comb Generator
........................................................ HP 8406A
Adapter, Type N (m) to BNC (f) (2 required) ............................... HP 1250 - 0780
PROCEDURE:
1.
Set equipment controls as follows:
Spectrum Analyzer:
FREQUENCYBANDGHz .................................................. .01-3
TUNING .............................................................. 3.000GHz
FREQUENCY SPAN/DIV .................................................. 100 kHz
RESOLUTIONBW
........................................................ lOkHz
INPUT ATTEN ............................................................. 30 dB
REFERENCELEVEL
.................................................... -20dBm
REFLEVELFINE .............................................................. 0
Amplitudescale .............................................................. LIN
SWEEPTIME/DIV ........................................................ AUTO
SWEEPTRIGGER
..................................................... FREERUN
.....................................................................
ALTIF OFF
.................................................................
SIGIDENT OFF
BLCLIP
.................................................................... OFF
VIDEOFILTER
............................................................. OFF