10. Step Gain And 18.4 Mhz Local Oscillator Adjustments - HP 8568B Performance Tests And Adjustments Manual

10. Step Gain and 18.4 MHz Local Oscillator Adjustments

10. If A4A5R33 CAL adjustment does not have sufficient range to
adjust trace to the top CRT graticule line, increase or decrease the
value of A4A7R60 as necessary to achieve the proper adjustment
range of A4A5 CAL adjustment. See Figure 3-39 for the location
of A4A7R60. Refer to Table 3-3 for range of values for A4A7R60.
10 dB Gain Step Adjustment
11. Connect CAL OUTPUT to RF INPUT through 10 dB step
attenuator and 1 dB step attenuator.
12. Key in LOG
(
ENTER
13. Set step attenuators to 25 dB.
14. Key in MARKER A. Signal trace should be at the center CRT
graticule line, and MKR A level, as indicated by CRT annotation,
should be .OO dB.
15. Key in
[
REFERENCE LEVEL
16. Adjust A4A5R32 SGlO for MKR A level of .OO dB (CRT MKR A
annotation is now in upper right corner of CRT display). See
Figure 3-48 for location of adjustment.
Figure 3-48. Location of 10 dB Gain Step Adjustments
17. If A4A5R32 SGlO adjustment does not have sufficient range to
perform adjustment in step 16, increase or decrease the value of
to 'Ihble 3-3 for range of values for A4A7R60. Repeat steps 3
through 16 if value of A4A7R60 is changed.
the
18. Key in
[
REFERENCE LEVEL
19. Adjust A4A5R44 SG20-1 for MKR A level of .OO dB. See
Figure 3-48 for location of adjustment.
Key in
20.
LEVEL
21. Adjust A4A5R54 SG20-2 for MKR A level of .OO dB. See
Figure 3-48 for location of adjustment.
1 dB and
[
REFERENCE
-40 dBm. Set step attenuators to 35 dB.
]
proper adjustment range of
the
-50 dBm. Set step attenuators to 45 dB.
]
-70 dBm. Set step attenuators to 65 dB.
)
-30 dBm.
Adjustments 3-89