ADJUSTMENTS

MODEL 8559A

ADJUSTMENTS

5-22. 3-dB BANDWIDTH ADJUSTMENTS(Cont'd)

Adjust A9R72 XTL to bring signal level to the fifth graticule line (three divisions from the top graticule line).

Increase signal generator frequency until signal on CRT display peaks and then decreases t o the fifth graticule line. Record counter frequency.

Compare new frequency with frequency recorded in step 14. The difference between the two frequencies should be 2800 t o 3200 Hz. If the bandwidth is not within limits, repeat steps 12 through 17, slightly readjusting A9R72 XTL, until the specified limits are achieved.

Set RESOLUTION BW to 10 kHz. Tune signal generator to peak signal on CRT display.

Adjust REF LEVEL FINE to place signal at 7.1 divisions.

Decrease signal generator frequency until the signal on the CRT display is at the fifth graticule line. Record this frequency.

Increase the signal generator frequency until the signal on the CRT display peaks and then decreases t o the fifth graticule line. Record this frequency.

Compare new frequency with frequency recorded in step 20. The difference between the two frequencies should be 9.000 kHz to 11.000 kHz.

NOTE

A9R72 XTL may be further adjusted to bring the 10 kHz and 1 kHz bandwidths within limits; however, the final measurement of the 3 kHz bandwidth must be between 2700 Hz and 3300 Hz. (If the 10 kHz bandwidth cannot be brought within limits by adjusting A9R72 XTL, change the value of factory- selected resistor A9R111*. If the 1 kHz bandwidth cannot be brought within limits by adjusting A9R72 XTL, change the value of A9R109*.)

Set RESOLUTION BW to 1 kHz. Tune signal generator to peak signal on CRT display.

Adjust REF LEVEL FINE to place signal at 7.1 divisions.

Record the counter frequency.