MODEL 8559A

ADJUSTMENTS

ADJUSTMENTS

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

NOTE

If the 100 kHz bandwidth is not within the specified limits, change the values of factory-selected resistors A11R19*, A11R43*, A13R19*, and A13R43*. If the bandwidth is too wide, increase the value of the resistors; if the bandwidth is too narrow, decrease the value of the resistors. The factory -selected resistors need not be of equal value, but each must be within one standard value of the others.

8.Set RESOLUTION BW to 30 kHz and FREQ SPAN/DIV to 10 kHz. If necessary, reset signal level with REF LEVEL FINE control. The bandwidth should be between 2.6 and 3.4 divisions at the fifth graticule line.

NOTE

If the 30 kHz bandwidth is not within the specified limits, change the values of factory-selectedresistors A11R23*, A11R48*, A13R23*, and A13R48*. If the bandwidth is too wide, decrease the value of the factory-selectedresis- tors; if the bandwidth is too narrow, increase the value of the resistors. The factory-selectedresistors must be within three standard values of the nominal value.

9.Connect signal generator as shown in Figure 5-8. Tune signal generator to approximately 21.4 MHz. Set the signal generator to approximately 0 dBm and the step attenuator to 10 dB. Set COUNTER MODE to EXPAND X 100.

10.Place spectrum analyLeron right side and connect test cable to Third Converter 21.4 MHz output connec- tor A16J3. If connector is not present (some early instruments were not so supplied), remove AlOWl from A5J2 and connect AlOWl through a 10 dB step attenuator set to 30 dB and the signal generator set for a

-10 dBm output level. The 10 dB step attenuator between BNC tee and frequency counter can be elirni- nated.

11.Set H P 8559A RESOLUTION BW to 1 MHz. Tune signal generator to peak signal on CRT display (near 21.4 MHz) (321.4 MHz if injecting into AlOWl). Adjust the output level of signal generator to place the signal at 7.1 divisions.

12.Set RESOLUTION BW to 3 kHz. Tune signal generator to peak signal on CRT display.

13.Adjust REF LEVEL FINE to place signal at 7.1 divisions.

14.Note the counter frequency and tune the signal generator 1500 Hz below the center frequency noted. Record the new counter frequency.