HP 8559A Comb Generator, PERFORMANCE TESTS, 4-13. RESIDUAL FM

PERFORMANCETESTS 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	PADAPTER
FIGURE 4-5.RESIDUALFM TESTSETUP
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