MODEL 8559A

ADJUSTMENTS

ADJUSTMENTS

5-21. BANDWIDTH FILTER ADJUSTMENTS (Cont'd)

CHECK CENTERING

HERE (SPIKE IS

CRYSTAL RINGING)

CHECK SYMMETRY

HERE (LOW ON SKIRTS)

FIGURE 5-7.ADJUSTINGCRYSTALSYMMETRY AND CRYSTALCENTERING

Remove crystal short from A13TP1/TP2 and connect it across A13TP4/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 A1lTP4/TP5 and connect it across A13TPl/TP2.

Adjust A11C54 CTR for minimum signal amplitude. Then adjust A11C38SYM and AllC54 CTR for a centered and symmetrical bandpass.

Remove crystal short from A1lTPl/TP2 and connect it across A1lTP4/TP5.

Adjust A1 1C25 CTR for minimum signal amplitude. Then adjust A11C15 SYM and A11C25 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 TUNING 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.