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PerformanceCheckprocedure- 4g4A/4g4ApServiceVol.1

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Figure 4-4. Cenler frequency drift with the 1st LO tocked.

5. CheckCenterFrequencyStabilitv

lplrl i.f 50 Hzlmin'orr".J *itii-'irtLo tocked (SPAN/DV<200kHz for band 1 and bands 5 through 12, and SPAN/DV<I0OkHz for bands 2 through4) after t hour of warmuptime in a stable ambienttemperature).

a.ApptytheCatibratorsignaltothe RFtNpUT.

b.Setthe SpectrumAnalyzercontrolsas follows:

CENTERFREQUENCY 1OOMHz

SPAN/DIVS0Hz

AUTORESOLN ON

REFLEVEL-15 dBm

MINRF ATTENdB O

VERTICALDTSPLAY 2 dB/Dlv

TRIGGERING FREERUN

VEWA andVEWB On

TIME/DIVAUTO

READYlightto go out.

d.Afterthe READYlight is out,activateSAVEA.

e.Activatethe NABROWVTDEOFILTER.Whenthe NARROWVIDEOFILTERis acivated,the AUTOsweep modeslowsthe sweepto 10 s/div.

WhCN thE NARROW VIDEO FILTER iS acivated, the UNCAL light will come on. The light shouldbe ignoredfor purposesof this check.

f.Press SINGLESWEEPagain and wait for the READYlightto go out.

g.Notethe disptacementbetweenthe SAVEA peak and the VIEW B peak. This is a measureof the fre- quencydrift.

h. check that displacementof the vtEw B peak is no more than 1 divisionin the positivedirection,or 0.72 divisionin the negativedirection. SeeFigure4-4.

6.Check Residuat FM

{Witnin7N kHz over20 ms with the i st LO unlocked (SPAN/DV>200kHz for band1 and bands s through 12 and SPANIDfV>10OkHzfor bands 2 through4.))

{Within(10 + 2N)Hzover 20 ms with the 1st LO locked(SPAN/DV<200kHz for band 1 and bands5 through 12 and SPAN/DV<IO0kHz for bands 2 through4.)l

a.Applythe Catibratorsignattothe RF tNpUT.

b.Set the SpectrumAnalyzercontrolsas follows:

CENTERFREOUENCY	100MHz
SPAN/DIV	1 MHz
RESOLUTIONBANDWTDTH 100kHz
VERTICALDTSPLAY	2 dB/DtV
MIN RF ATTENdB	O
REFLEVEL	-23 dBm
TIME/DtV	20 ms
TRIGGERING	FREERUN
VIEWA and VIEWB	On

c. Disable the 1st LO synthesisand phase lock by pressing <Blue-SHIFT> 10 dB/DlV. A message "FRE- OUENCY CORRECTIONSDTSABLED: USE HELp,.wiil be displayed on the CBT.

cl. Reset the SPAN/DIV to 100 kHz, and recenter the 100 MHz calibrator signal on screen with the CENTERFREOUENCYcontrot.

E. SEt thE VERTICALDISPLAYtO LIN. POSitiONthE signal so the slope (horizontalversus vertical excursion) of the response can be determinedas illustratedin Fig- ure 4-5A. Slope determination may be made easier by switching VIEW B off, and using SINGLE SWEEp and SAVE A to freeze the display at a convenient position on the graticule. The slope should calculate to approxi- mat€ly 10 kHzldivision.

4-9