Tektronix 494AP O o o o o o o o o o o o o o o o, Adfustment Procedure- 4g4Ll4g4ApServtceVot

Adfustment Procedure- 4g4Ll4g4ApServtceVot. 1

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Flgure5€. DeflectionAmptilier test points and adiuetments.

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q.Monitor the collectorsof e1095 and e20g6, on the DeflectionAmplifierboard,with test oscilloscope.

r.AdjustC5104tor best response.

s, Disconnectthe test oscilloscope. Check the appearanceof the letter *Z'" GHz of the frequency

in

readout,and if necessarytreadjustCS1O4and C406i (verticaloutput)for the straightesttop on the letter"Z-.

t.set the vERTtcAL DtspLAy to LtN,TME/DVto MNL, the REF LEVEL for 100UV (100pV),and the MANUALSCANcontrolfullyclockwise.

u.Adjust C5021 and C4057 for best REF LEVEL readout(straightestleters and numerals).

4.Adjust Digital Storage Calibration (R1040,Rl050, R1055,and R1060on the Horizontal Digital Storage board; and R1033, R1Og4,R1045 and R1046on the VerticalStorageboard)

Start the Digital Storage Calibration routine by pressing <Blue-SHIFT> PULSE STRETCHER,and selectingitem 2 (DIGITALSTORAGECAL.) Foilowthe instructionsthat ar€ displayedon the crt.

Referto Figure5-7for adjustmentlocations.

5.Adiust Sweep Timing (Rl062 on the Sweepboard)

a. Connectthe test equipmentas shown in Figure

5-8. Set the followingSpectrumAnalyzercontrols:

FREQSPAN/DV 10 MHzor tess

TIME/DV 10 ms

TRIGGERING EXT

5-8

b.Connecta jumper between pins 1 and 5 (Ext Video Selectand Groundrespectivety)on the ACCES- SORIESconnector.

c.Set the Tim€ Mark Generatorcontrolsfor 10 ms timEmarks.

d.AdjustSweepTiming,Rl062 (seeFigure5-9)for 1 markerper division. (UseHorizontalPositionadjust- mentto alignmarkerswith graticulelines.)

e.Checkthe accuracyof the remainingTIME/DIV

selections. Error over the center eight divisionsmust

not exceed !.5 o/o.

f.R€set the TIME/D!vto AUTo, FREQSPAN/DV tO MAX, TRIGGERINGtO FREE RUN, ANd ACtiVAtE

AUTORESOLN.

g.Removethe jumperbetweenpins 1 and 5 of the ACCESSORIESconnector. Reposition the trace if movedin partd.

6.Adjust Frequency Control System and Dot Marker position (R1028,R1032,R3040,and R4040on the CF Con- trol board;R1031,R1032,and R1034on the 1st LO board; R1063,R1065,R1067,and R1071 on the Span Attenuatorboard; C1013and C2011on the Controlled Oscillator board: and R1052 on the Sweepboard)

R1028, R1032, R3040, and R4040 on the CF Control board: Rl031, R1032, and R1034 on the 1st LO board: and C'!013and C2011 on the Controlled Oscillator board are adjusted in part d.

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