Tektronix 494AP service manual A o o o a o o, A o a o o o a, A a, CoME

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PerformaneeCheck procedure _ 4g4Al4g4ApServlce Vol. 1

SPECTRIfr AI{I.AYZERUI{OERTEST

coME

OENERATOR

MOOULE

Figure 4-7' Test equipment setup for checklng frequency span/Dlv and sweep Time/Div accuracy.

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9.TimeAccuracy ^C.*:*_qyegp (WithinS%oftherateserecitJi'

a. Connectthe	outputof the Time Mark Generator
to the rear-panet
MARKERI/DEO
	input.--6'onnect
of J104 ACCESSORY		pin 1
		(connect
pin 1 to pin S).	connectorti-groiio

-.b. _Setthe SpectrumAnalyzerTIME/DVto 20 ps, and activatezERo SpANanotNTrireb-lnjr.rc.

Disabledigitalstoragefor sweeptimesfas- t€r than2 ms.

c. Set the Time Mark Generatorcontrolsfor 20 ps timemarks.

d. use the horizontalposlTloN controtto align a marker..onrhe 1st graticute

checkthe displacement tine (seeFd;; 4-B),thentive positionsover the of markerstrori-ineirrespec-dispfacementmustnot c€nter eight divisions.Marker

exceedS/o overthe display.

e. check the accuracyof the 20 ps to 5 s TIME/DV ::l!'!.S_rby apptying appropriate markers ,or each TIME/DlV setting and noting the displac€mentas describedin part d of this step.

f. Disconnectthe-test_equipment,

and the shorting

strapfrom pin 1 of Jl04 ACCESSORyconnector.

10.Check Pulse Stretcher

a. Apply .1 ms time marks,from the Time Mark Generator, to the RF lNpUT. Set the spectrum Analyzercontrolsas follows:

CENTERFBEOUENCY	2.0MHz
ZEROSPAN	On
RESOLUTTONBANDWIDTH 100kHz
REFLEVEL	0 dBm
VERTICALDISPLAY	10dB/Dtv
TtME/DtV	. 1 ms
VIEWA andVIEWB
	off
TRIGGERING	INT

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