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AdrustmentProcedure- 4g4A/4g4ApServlceVot,I

DC503A

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Figure5-27. Opton 42 adiustmenttest equipmentsetup.

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c.set the 7L14Time/Divto Manual,and adjustthe crt beam (dot)to centerscreen.

d.The DC503Areadout shoutd indicateapproxi- mately 110.000MH2.Set Level as nec€ssary,and set the 7L14 Center Frequency for an indication of 110.0MHz.

e.set the 7L14Time/Divto catibrateddisplay.

f.Adjust C1016,C1020 and C1024for maximum amplitude, symmetryand bandpass (3 dB and 6 dB points).

(1)Adjust the bandwidthsymmetry+0.5 divisions

(r1 MHz)at th€ 3 dB and 6 dB points.

(2} Check that bandwidth at the 3 dB point is 7.5 MHz,*1.5 MHz.

(3)Checkthat 3 dB and 6 dB pointsare equidistant from centerscreenwithin0.5 division.

(4)Checkthat any ripple presenton the waveform is (0.2 div(0.4dB).

Aslightchangein displaymay be observed whenthe coveris reinstalledon the module.

S.Checkthe CoupledFonuardGain (tF OUT port P1O24l.

(1)Set the 7L14 Spectrum Analyzer Reference Levelto 0 dBm.

(2)Checkthat the displayon the 7L14is between4 and7 divisionsin amplitude(-5 dBm, i3 dBm).

h. Checkthe InputCompression.

(1)Increasethe TR502Output Level and REFER- ENCE LEVEL setting in 1 dB incrementsuntil the amplitudedisplayedby the 7L14 decreasesby 0.5 division(1 dB compression).

(2)Checkthat the signaldisplayedon the 7L14indi- cates)0 dBm.

i. CheckForwardGain

(1)Return the TR502 Output Level to -25and removethe connectionto the modulo]F OUT.

(2)Connecta 50o terminationto the lF OUT con- nector,P1024.

(3)Connectthe OUT(P1012)connectorto the 7L14 RF Inputwitha 50o cable.

(4)Adjust the 7L14 Reference Level until the displayedsignalis nearfull screen(8 divisions).

(5)Checkthat the signaldisplayedon the 7L14indi- cates -20dBm to -23dBm (-21.5 dBm *1.5 dBrn).

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5-30

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