HP 428B Operating And Service Manual page 49

Model 428B
Circuit -hp- Stock
Reference No.
R110 0727 -0218 fxd, dep c, 180K ohms ±1%,
S1 428B -19A Assembly: range switch, includes,
R2 thru R20, R61, R62
S2 3101 -0001 Switch: tog, SPST
S3 3101 -0018 Switch: tog, SPST, momentary
S4 Not Assigned
S5 3101 -0033 Switch, sl DPDT
T1 9120 -0052 Assembly: transformer, interstage, includes,
C14, C18
T2 428A -60G Transformer, detector signal
T3 428A -60C Transformer, gate
T4 428B -60J Transformer, zero balance
T5 9120 -0051 Transformer, osc
T6 428A -60D Transformer, head drive
T7 9100 -0104 Transformer, power
V1, 2 1923 -0017 Tube, electron:
V3, 4 1930 -0013 Tube, electron:
V5 1923 -0017 Tube, electron:
V6, 7 1932 -0022 Tube, electron: 6DJ8 / ECC88
V8 1932 -0029 Tube, electron:
V9 1921 -0010 Tube, electron:
V10 1923 -0021 Tube, electron:
V11 1940 -0001 Tube, electron:
MISCELLANEOUS
428A -21A Assembly: probe, includes
L1 thru L4, P1
428B -65C Assembly: circuit board "C" includes
R65, R67, P68
428B -75H Assembly: circuit board "A" includes
C32, C66, C69, CR9, CR10, Q1 thru Q3, R70,
R71,
428B -75B Assembly: resistor board "B" includes
C13
C15
C21
C25
R21 thru R23
428B -75C Assembly: circuit board "C" includes
C16, C17, C24, C41, C42, R30 thru R33
R43, R44 R77 thru R79,
428B -75D Assembly: resistor board "D" includes
C1, C2 C11, C12
42
Description#
1/2 W
6AH6
6AL5
6AH6
12AU7
12B4A
6AU6
5651
R74, R75, R102
R26, 27
R35, 36
R41, 42
R45
R73
R81, R85, R86
R1 R25
Circuit
-hp- Stock No.
Reference
428B-75E Assembly: resistor board "E" includes
C27 thru C29
R94 thru R96
428B-75F Assembly: resistor board "F" includes
C53, C54 C68
G-74AW Knob:
G-74J Knob:
G-74N Knob: bar,
1200-0003 Socket, tube:
1200-0017 Socket, tube:
1400-0008 Fuseholder
1400-0084 Fuseholder
1450-0020 Jewel, pilot light
8520-0017 Electric shaver brush
1205-0011 Heat dissipater, semiconductor
Description#
C51 R47 thru R52
R72 R91
CR1 thru CR8 R106
R108 R110
red, 3/4" w/arrow
black, 1", concentric shaft ZERO
RANGE
9 pin miniat
7 pin miniat