Tektronix 494AP O o o o a o o, Corect re3ponsetor g29 MHr tlrlrd and fourth resonators

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Malntenance- 4g4A/4g4Apservice vot. 1

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Frequency

FrequencySpan/Div

ReferenceLevel

AutoResolution

VerticalDisplay

DigitalStorage

TimelDiv

Triggering

2GHz

10MHz +20 dBm On

10dB/Div

V i e w A & V i e w B Auto FreeRun

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A 3rd Resonator

Retu?nLo-ss>12 dA

B. 4th Resonator and Fllter

Figure 6-17.Corect re3ponsetor g29 MHr tlrlrd and fourth resonators.

1.Check 2nd LO Frequency (2182 MHz *i MHz)

...The referencefrequencypositionset up in this step will alsobe usedin the adiustrnentprocedure.

a.Connect the test equipment as shown in Figure6-18.

b. Set the Spectrum Analyzer to Band 1 and Max Span.

c, Set the test spectrum analyzer front-panel as fol- lows:

d.Set the TimeMark generatorfor 0.1Fs markers. Markersshould appearon the test sp€ctrumanalyzer display,approximatelyone marker/division.

e.Pressdegauss,and peak the 2.0 GHz signalfor maximumamplitudewith the peakingcontrol,if avail- able.

f.Usingthe 2 GHz signalas a startingpoint,begln countingmarkersuntilthe 18th markeris located. The 2 GHz signal shouldbe greaterin amptitudethan the time markers. The frequencymust be tuned towards

2.18GHz to locatethe 18thmarker. Increasethe refer- encelevelas necessaryto viewthe markers.

S.Center the 18th marker on the test spectrum analyzer (center frequency should be approximately 2.18GHz).

h.Reset the test spectrum analyzer frequency span/divisionto 1 MHz.

i.Positionthe 18thmarker2 majordivisionsto the left of the center graticuleline on the test spectrum analyzer (center frequency should be approximately 2.182GHz),thenactivateSAVEA.

J.Disconnectthe output of the comb generator from the rf inputof the test spectrumanalyzer.

k.Resetthe ReferenceLevelof the test spectrum analyzer to +10 dBm. Connect the 2ND LO output, from the spectrumanalyzerundertest, to the rf inputof the test spectrumanalyzer.

l.Checkthat the 2nd LO outputsignalis withinone majordivisionof the centergraticuleline(2.181GHzto 2.183GHz).

m.lf the frequencyof the znd Lo is greaterthan

2.1813 MHz or less than 2.181 MHz, adjustmentis required. The SAVEA displayreferenceused in part I will be usedin the adjustmentprocedure.

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