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MODEL 8559A

ADJUSTMENTS

21.

BANDWIDTH FILTER ADJUSTMENTS

(Cont'd)

CHECK CENTERING

HERE (SPIKE IS

CRYSTAL RINGING)

CHECK SYMMETRY

HERE

(LOW

ON SKIRTS)

FIGURE

5-7.

ADJUSTING CRYSTAL SYMMETRY AND CRYSTAL CENTERING

Remove crystal short from A13TP 1 /TP2 and connect it across A1 3TP4/TP5.

Adjust A13C25 CTR for minimum signal amplitude. Then adjust A13C15 SYM and A13C25 CTR for a

centered and symmetrical bandpass.

Remove crystal short from A1

lTP4/TP5 and connect it across A13TPl/TP2.

Adjust A1 1C54 CTR for minimum signal amplitude. Then adjust A1 1C38 SYM and AllC54 CTR for a

centered and symmetrical bandpass.

Remove crystal short from

A1 lTPl/TP2 and connect it across A1 lTP4/TP5.

Adjust A1 1C25 CTR for minimum signal amplitude. Then adjust A1 1C15 SYM and A1 1C25 CTR for a

centered and symmetrical bandpass.

Remove the crystal shorts.

Set FREQ

SPAN/DIV to 10 kHz and RESOLUTION BW to 30 kHz. Center signal on CRT with TUN

ING control.

Switch RESOLUTION BW from 30 kHz to 10 kHz and back several times. Verify that signal shift does

not exceed 3 kHz (0.3 divisions). If signal shift is out of tolerance, return to step 11.

HP 8559A User Manual

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