HP 652A Operating And Service Manual page 68

Model 652A '
This manual backdating sheet makes this manual applicable to earlier instruments.
Instrument-component values that differ from those in the manual, yet are not listed in
the backdating sheet, should be replaced using the part number given in the manual.
!
nstrum ent S erial Pr e fix
632-00250 and below
954·021 3 5 and below
Blue Instruments
Below 0964A02771
0964A03070 and below
9 1 1·01 736 and below
CHANGE No. 1 Delete A2C25·
Delete A2R46
Change A2C l l to 200 microfarads, -hp- Part No. 0 1 80-0060.
Change A2CR5 to a breakdown diode, 7.87 V +/- 2%, -hp-
Change A2Q7 to 2N3393, -hp- Part No. 1 854-02 1 8 .
Change A2R25 t o 1 1 .75K, -hp- Part No. 0757-0757.
Change circuitry associated with A2Q7 in Figure C·l .
MANUAL BACKDATING C H A N G E S
MODEL 652A
TEST OSCILLATOR
Manual Serial Prefixed: 623, 632, 8 1 2,
-hp- Part No. 00652-90002
Make Manual Chang e s
No. 1
No . 2
No. 3
No. 4
No. 5
No. 6
Part No. 1 902-0778.
.
K
' .
'
'
"
.
R24 IK
lell
200
R23 47
R22 2K
/0
Figure C·1. P Oscillator Circuit.
826, 9 1 1 , 954,
0964A.
I nstrum ent S erial Pr e fix
1 226A·04 1 70 and below
1 226A·04309 and below
CI7
1.8
J
CR8
CR9
Appendix C
Make Manual Chang e s
No. 7
No. 8
C·l