Tektronix 494AP O o a o o a o o a a o o o o o o o o o o o o o o, O o o o o o o o a

Adlustnent Procedure- 494ful4g4ApServtceVot. 1

Flgure5-16.100kHzoverl0 kHzlitterrespona€.

(1)Set the, foltowing adjustmentsto midrange: R4025on the VR 2nd FitterSelectboard,and R3OIO 'andR3025 in the 10Hz/100H2 BandpassFitter assembly.

(2)Installjumpers on J30i5, JgogS,and J3052 in the 10 Hzll00 Hz Fitterassembty(Figure5-ig).

(3)Applythe CALOUTsignatto th€ RF tNpUT,and set the SpectrumAnalyzercontrolsas follows:

FREQUENCY100MHz

FREQSPAN/DV100Hz

AUTORESOLNOff

RESOLUTTONBANDWTDTH 100Hz

VERTCALDTSPLAY 2 dB/DtV

REFERENCELEVEL -20 dBm

Throughoutthe 10 Hz ftlter adiustment,set the REFERENCELEVELas neededto main- taina 7-divisionexcursionof the display.

(4)Adjust R4025on the VR 2nd FilterSet€ctboard (Figure5-17)for maximumsignalamplitude.

(5)SetTIME/DVto 50 ms. (6) AdjustRg0i0 in the 10 Hzl100Hz BandpassFitter assembty(Figure5- 18)for maximumsignalamplitude.

0Adjust R3025in the 10Hz/100H2 Bandpass Filterassemblyfor maximumsignalamplitude.

(8)Removethe jumperfrom JO01S(1st stageof the bandpassfilter)in the 10 Hzl100Hz BandpassFilter assembly.

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(9)Adjust C1032 in the loHz/lfi)Hz Bandpass Filterassemblyfor maximumslgnalamplitude.

(10)Set the SpectrumAnalyzercontrolsas follows:

FREQSPAN/DIV	'10
	Hz
RESOLUTIONBANDWIDTH	10 Hz
VERTTCALDTSPLAY	5 dB/DlV
TME/DV	AUTO

(11)Press (Blue-SHIFT>WIDE and selectitem

#3 CTOGGLEEOSCORRECTTONMODE).

(12)Resetthe CENTERFREQUENCYas necessary to centerthe 100MHz calibratorsignal,thenset the REFERENCELEVELfor a seven-divisionexcursion of the display.

(13)ActivateSAVEA. Store s€ttings in register1 by pressing<Blue-SHIFT>STORE1.

(14)Setthe SpectrumAnalyzercontrolsas follows:

FREQSPAN/DIV100Hz

RESOLUTIONBANDWIDTH 100Hz

VERTICALDTSPLAY 10 dB/DlV

VIEWAOtr

(15)Store settingsin register2 by pressing<Blue- SHIFT> STORE2.

(16)Adjust C4015in the 10Hz/100H2 Bandpass Filterassemblyfor b€st symmetry.

(17)PressRECALLSETTINGS1.

(18)Adjust C4028In the 10Hz/100H2 Bandpass Filtsr assembly to match th€ trequency of th€ B displayto that of the sAVE A display.

(19)Repeat adiustmentof C4015 and C4028 to eliminateinteraction.

(20)Removethe jumper from J3038 (2nd stage of the bandpassfilter) and install it on J3015 in the 10 Hzl100Hz BandpassFilterassembly.

(21)PressRECALLSETTINGS1.

(22)Adjust C4036in the 10Hz/10OHzBandpass Filter assemblyto matoh th€ frequencyof the B displayto that of the sAvE A display.

(23)PressRECALLSETTINGS2.

(24)Adjust C4045 in the 10 Hzl100Hz Bandpass Filterassemblyfor best symmetry.

(25)Repeat parts 22 through 25 to eliminate interaction.

(26)Removethe jumper from J3052 (3rd stage of the bandpassfilter) and install it on J3038 in the 10 Hzll00 Hz BandpassFilterassembly.

(27)PressRECALLSETTINGS1.

(28)Adjust C4051in the 10Hz/100H2 Bandpass Filter assembly to match the frequ€ncy of the B displayto that of th€ SAVEA display.

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