Wavetek 171 - Page 27

FNCHECK
NOTE: Unless otherwise indicated, test points and designations apply to synthesizer
(lower) board and digital switch settin!}s are between
0.
1000
and
1.9999.
OLTAGE
AT
TP8 (APPRO
0.5 TO
5V)
NOT
PROPOR-
TIONAL
TO
DIGITAL
SWITCH SETTINGS
-
FREQUENCY FREQUENCY
AT
PIN
4
IC20 (10k
-
AT
PIN
11
IC14 (1M - CHECK
200
kHz)
PROPOR-
~
20
MHz) PROPOR- NO
...
SYNTHESIZER
LOOP
<TIONAL
TO
DIGITA~
TIONAL
TO
DIGITAL
~---1
....
-
(SHEET
2)
SWITCH SETTINGS
SWITCH SETTINGS
'fvEs
NEGATIVE
PULSES
AT
PIN 6
IC20 (10k
-
<
200
kHz)
PROPOR-
=nONAL
TO
DIGITAL
SWITCH SETTINGS
?
YES
POSITIVE PULSES
<
(10k-
200
kHz)
AT
COLLECTOR OF
06
.,
~s
POSITIVE
DC
SIGNAL
AT
<
PIN
6
IC21 PROPOR-
TIONAL
TO
DIGITA
SWITCH SETTINGS
CHECK
IC25
CIRCUIT
?
YES
CHECK
IC20
CIRCUIT
CHECK
Q5,6
CIRCUIT
CHECK
IC21
CIRCUIT
FREQUENCY
ATPIN
11
IC15 (100k -
<
.
2
MHz) PROPOR-
:Y-IONAL
TO
DIGITAi:::
SWITCH SETTINGS
?
YES
CHECK
IC15
CIRCUIT
Figure 6-4. Synthesizer Mode Checks (Sheet 1
of
6)
CHECK
IC14
CIRCUIT
6-7