Tektronix 494AP O a a o a o a, O a o O o a o A o, CheckResolutionBandwidth and shape Factor

PerformanceCheckprocedure- 4g4A/4g4ApServiceVol. 1

b.ActivatePULSESTRETCHERand norethat this modeextendsthe talttime of the markers.

c.Removethe test equipment.

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Figure 4€. Typlcal display for measuring Time/Div accuracy.

11.CheckResolutionBandwidth and shape Factor

(6 dB bandwidth within 2ov" of the s€lected bandwidth;shape factor is 7.S:l or less lor all bandwidthsotherthanthe 1OHz bandwidthwhichis 12:1or less)

a.Applythe CALOUTsignatto the RF lNpUT. Set the SpectrumAnalyzercontrolsas follows:

CENTERFREQUENCY	100MHz
sPAN/DrV	1 MHz
RESOLUTIONBANDWIDTH 3 MHz
REFLEVEL	-20 dBm
VERTICALDISPLAY	2 dBlDtv
MINNO]SE	Activated
PEAK/AVERAGE	FullyClockwise
TrME/DrV	AUTO
TRIGGERING	FREERUN

b, Measurethe 6 dB down bandwidth(seeFigure 4-9A).Bandwidthshoutdequal3MHz *600 kHz.

c.Resetthe vERTtcALDtspLAyto 10 dB/Dtvand measurethe 60 dB downbandwidth(seeFigure4_gB),

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Figure 4-9. Typical display for measuringbandwldthand shapefactor.

d. Check that the shape factor is 7.5:1 or less. The shape factor is the ratio of -60dB/-6 dB bandwidths {see Figure4-9).

e. Reset the RESOLUTIONBANDWIDTHto 1 MHz, SPAN/DIV to 500 kHz, and VERTICAL DISPLAY to

2dB/DrV.

f. Check the resolution bandwidth and shape factor of the 'tMHz filter by repeating parts b through d.

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