HP 8970B - 20 MHz IF Assembly Modifications

HP 8970B Option 020 Service Manual Supplement 4-3
Board Differences
20 MHz IF Assembly (08970-60050)
20 MHz IF Assembly (08970-60050)
The 08970-60050 assembly has been created from the 08970-60003 assembly with the
following changes.
1. C83 changes from 7.5 pF (0160-3029) to 4.7 pF (0160-3873)
2. R8 changes from 110 Ω (0757-0402) to 162 Ω (0757-0405)
Figure 4-1: Schematic differences in 08970-60050
1
1.Differences are highlighted with a shaded background.
+15V (F1)
C23
0.01 uF
L11
22 uH
C22
0.01 uF
R8
162 Ω+15V (F1)
R6
1000 Ω
C83
4.7 pF
R10
51.1 Ω
C26
56 pF
L12
1.5 uH
C24
0.01 uF
R9
1780 Ω
-15V (F1)
R7
1000 Ω
20 MHz BANDPASS FILTE
R
14.6 TO
15.3 Vdc
6.5 TO
6.9 Vdc
7.3 TO
7.7 Vdc
2
Q20
C
2
20
C21
0
1 uF