ADJUSTMENTS

MODEL 8559A

ADJUSTMENTS

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

Adjust FINE TUNING and REF LEVEL FINE controls for a centered signal at 7 divisions from bottom graticule line.

Remove shorts from A13TP3 and A13TP6 and center signal with FINE TUNING control. Adjust A13R26 LC for a signal amplitude of 7 divisions. Replace shorts on A13TP3 and A13TP6.

Remove shorts from A1 lTP3 and A1 1TP6. Adjust A1 1R26L C for a signal amplitude of 7 divisions.

Repeat steps 36 through 40 until no further adjustment is necessary. Remove shorts from AllTP3 , A1 lTP6, A13TP3, and A13TP6.

Adjust A11R31 XTL and A13R31 XTL fully counterclockwise.

Set RESOLUTION BW to 1 kHz and FREQ SPAN/DIV to 10 kHz. Center signal with FINE TUNING control. Adjust A1 lR31 XTL and A13R31 XTL equally for a signal amplitude of 7 divisions. Each potentiometer should be adjusted to accomplish half the necessary increase in signal amplitude.

Remove jumper from A9TP6 and A9TP8.

Set FREQ SPAN/DIV to 500 kHz and RESOLUTION BW to 3 MHz.

Center signal with TUNING control. Adjust REF LEVEL FINE control for a signal amplitude of 7 divisions.

Step down RESOLUTION BW from 3 MHz tp 300 kHz. Variation in signal amplitude should be less than -t0.4 dB.

Set FREQ SPAN/DIV t o 10 kHz, TIME/DIV to AUTO, and step down RESOLUTION BW from 100 kHz to 1 kHz. Variation of signal amplitude should be less than -t0.7 dB from the 7th division reference.

Repeat steps 35 through 46 until variation in signal amplitude is within limits.

NOTE

If amplitude variation between crystal and LC poles exceeds specification, A11R7*IA13R7* can be replaced to bring the crystal poles to the amplitude of the LC poles.