10. Step Gain and 18.4 MHz Local Oscillator Adjustments
A4A5
STEP GAIN
R32
R44 R54
SGlO
SGZO-1
SGZO-2
R70 R62
A4A5
Figure 3-48. Location of 10
dB
Gain Step Adjustments
22. If
A4A5R32
SGlO
adjustment does not have sufficient range to
perform adjustment in step 19, increase or decrease the value of
A4A7R60
as necessary to achieve the proper adjustment range of
A4A5
SGlO.
See Figure 3-39 for the location of
A4A7R60.
Refer
to
‘Ihble
3-3 for range of values for
A4A7R60.
Repeat steps 9
through 21 if the value of
A4A7R60
is changed.
23. Key in [REFERENCE LEVEL) -50
dBm.
Set step attenuators to 45
dB.
24. Adjust
A4A5R44
SG20-1
for MKR A level of .OO
dB.
See
Figure 3-48 for location of adjustment.
25. Key in [REFERENCE LEVEL] -70
dBm.
Set step attenuators to 65
dB.
26. Adjust
A4A5R54
SG20-2
for MKR A level of .OO
dB.
See
Figure 3-48 for location of adjustment.
1
dB
Gain
Step
Checks
27. Key in
CREFERENCE
LEVEL] -19.9
dBm.
Set step attenuators to 15
dB.
Press MARKER
Ia]
twice to establish a new reference.
28. Key in
REFERENCE
LEVEL) -17.9
dBm.
Set step attenuators to 13
dB.
29. MKR A level, as indicated by CRT annotation, should be .OO
f0.05
dB.
If not, increase or decrease the value of
A4A5R86.
Refer to
Table
3-3 for range of values.
30. Key in (REFERENCE LEVEL] -15.9
dBm.
Set step attenuators to 11
dB.
31. MKR A level should be .OO f0.05
dB.
If not, increase or decrease
the value of
A4A5R70.
Refer to
‘Ikble
3-3 for range of values.
32. Key in [REFERENCE LEVEL) -11.9
dBm.
Set step attenuators to 7
dB.
33. MKR A level should be
.OO
f0.05
dB.
If not, increase or decrease
the value of
A4A5R62.
Refer to
‘Ihble
3-3 for range of values.
Adjustments 3-97
Commentaires sur ces manuels