Tektronix 494AP service manual A o o o c, Gpibverificationprogram

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7L14

CenterFrequency 1 1 0M H z

FreqSpan/Div 1 MHz

Hz Resolution 3 MHZ

ReferenceLevel 0 dBm

DisplayMode 2 dBlDiv

DigitafStorage off

TimelDivManuaf

Triggering

Source FreeRun

Mode Norm

VideoFilter On

DC 509

Function FrequencyA c h A

Source Ext

Atten X1

Coupl Dc

Opton 42

CENTERFREQUENCY t10MHz

FREQUENCYSPAN/DV 1 MHz

REFLEVEL_30 dBm

RESOLUTTONBANDWDTH 1 MHz

VERTICALDISPLAY 2 dB/DIV

MINRFATTENdBO

c.set the 7L14 dot to center screen with the ManualScancontrol.

d, Set the 7L14 CenterFrequencycontrotfor an indicationof 1j 0.0 on the f requeniyCo'unter.

e.swirch the FREQUENcy spAN/DlV control tgward-szerospan while keepingthe signaf centered with the oENTER FREOUENCYcontr'ot.The crt SPANiDIVreadoutwill indicate10 ms *t"n ."ro

is reached."p"n

f. set the 7L14Time/Divfor a catibrateddisptay, and set the ReferenceLevel and TR502Var dB for full screensignal.

g.Switch the TRS02Dot Intensity,,on",and reset the 7L'l4CenterFrequencyfor an indiiationo, 110.0on the FrequencyCounter.

h.Check that the 3dB bandwidth(1.5 divisions fromthe peakof the signal)is )5 MHz.

_^i: th-"-"!_thatany ripplepresenton the displayis <0.5 dB (0.25divisionsor tess).

PerformanceCheckprocedure- 4g4Al4g4ApServiceVol. 1

j.check that the waveformsymmetryis *1.0 MHz

(*1.O division)by checkingthatthe3 dBpointsas wetl as the 6 dB points on the waveformare equidistant from centerscreen. fl-hepeakof the signalmiy not Oe at centerscreen).

k.Reset the 7L14 Resolution Bandwidth to

0.3MHz,

l.Set the ZL14CenterFrequencycontrolsuchthat the intensifieddot is at th€ p€akof th; 7L14disptsr.-'--

m.Check that the frequencycounterindicatesa frequeancybetween1t g.5MHzanOt t t.S MHz.

GPIBVERIFICATIONPROGRAM

This verificationprogramcan be used with a TEK- TRONIX4050-SeriesComputerTErminalto check the operationof the GplB in the SpectrumAnalyzer. All interfacelinesand interfacemessages,excludingthose for parallelpoll,are verified.

In addition,the instrumentinterfaceis checkEdfor operationon other primaryaddresses,as well as the talk-onlyand listen-onlymodes.

The programis writtenin TEKTRONTX4OSOBASIC, and is dividedinto individualtests, eachfor a sp€cific interfaceline,message,or function. The tests start on even 1000 line numbersto allow easy modificationof the program.

The followingdescribesthe functionof eachtest in the program.

Lines 1-5000:lnterfac€sto user definablekeys for recoveryfrom a failedtest.

Lines5000-6000:Inputsthe primaryaddressof the SpectrumAnalyzerundertest (1 shouldbeused).

Lines 6000-7000:tD query response test. The instrumentmust be ableto talk and listen,to sendout its lD? responseand manipulateall eightof the DIO linesfor thetest to be successful,

Llnes7000-8000:Locallock-outtest. Testscorrect operationof the interfacemessagethat shoulddisable all programmablefront-panelcontrols.

Lines8000-9000:Go to LOCALtest. Tests correct operationof the interfacemessagethat shouldenable all front-panelcontrols.

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