HP 8642A Operating Manual page 554

3 U V ^ ^
A6A2
J4
DIVIDE-BY-1080 AND
COUNTER SIGNAL SWITCHING
A6A2
J2
FM LOOP
135 MH2
250 KHz
A6A2
J2
rlOSO
rO
125 KHz
TTL
i >
ABA2
J3
COUNTER < T
AUDIO
A6A2
J7
TO REAR '
PANEL *"T
[J4) EXT.
REFERENCE
rl2, 500
OF)
25.000
10. Hz
10 Hz/
AUDIO . . .
COUNTER CONTROL
LOGIC AND COUNT CHAIN
COUNT PERIOD
■< 5
COUNTER 45 MHZ
45 MHz/
AUDIO
COUNTED 45 MHz OR AUDIO
SS19
SS20 A6A2
J l
TIMEBASE
DIAGNOSTICS
-< 12
A5A2
J9
45 MHz
OSCILLATOR
fa
i>
A6A2
JB
v i f i i :
A6A2
J5
DIVIDERS
V i f i i :
A6A2
J2
- k 2
A6A2
J6
SS21 SS22
S5=SERVICE SHEET
rp
FM
135 MHz
i 1080
COUNTER
OUTPUT
TIMEBASE
DIAGNOSTIC
BUS
HET
45 MHz
SAKR
45 MHZ
10 MHZ
OUT
500 KHZ FM
REFERENCE
500 kHz
IF
REFERENCE
R e f e r e n c e Block D i a g r a m
C o m p o n e n t C o o r d i n a t e s
COMP
C60
C61
C62
C63
CS5
CBS
C67
C68
CBS
C71
C72
C73
C75
C76
C77
C78
C94
J2
R56
R57
R5B
R61
R62
R6B
U7
UB
U9
U10
U i l
U1B
U19
U20
U23
U24
X.Y
B. 2
B, 2
B, 2
B, 2
A, 2
B, 3
B, 3
B, 3
B. 3
A, 3
B, 3
B, 3
A, 2
B, 2
B, 2
B, 2
A, 3
A, 2
B. 2
B. 2
B. 2
B. 2
A. 2
A. 2
A, 2
A, 2
A. 2
B, 2
B. 2
A. 2
B. 2
B. 2
A, 2
B. 2
COMP
U25
U26
U27
U2B
U29
U33
U36
X.Y
B. 2
A. 3
A, 3
B. 3
B, 3
A. 3
A, 2
COMP
X.Y
COMP
<
X.Y
COMP
X,Y
COMP
X.Y
COMP
X,Y COMP X,Y COMP
X,Y
P/O A6A2 T I M E B A S E S S I 9
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ccc cu
ASSEMBLY W W ■ * #
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