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'
: e• - OUTPUT OF BUFFER AMPLIFIER —
OV ± 0.IV DC AT A2R44
OSCILLATOR OUTPUT
5.5-7V P- P AT A2 PIN 4
—+31V
± 0•5V DC AT A2 PIN I
- - 26V ± 0.5V DC AT A2 PIN 2
654A•J•1903A
ASS
OUTPUT
OF BUFFER AMPLIFIER —
3V ±
P- P AT A2R44
GREATER
SIGNAL
PHOTO RESISTOR LAMP
0-5V DC AT A2 PIN 5
PAIL
LESS
PHOTO RESISTOR LAMP
SIGNAL
4-6V DC AT A2 PIN 5
NO SIGNAL
FAIL
PASS
[
CHECK OSCILLATOR CIRCUIT ( A2)
PAIL
43V AC
Al
Al PIN 7
40V AC
AT AI PIN 4
PASS
PASS
0
BALANCED AMPLIFIER OUTPUT
OV ± 0.IV DC AT TOP OF A2R74
OV ± 0.IV DC AT BOTTOM OF A2R75
GREATER SIGNAL
CHECK PHOTO RESISTOR
A2DSVI LAMP AND RESISTOR
LESS
SIGNAL
CHECK + 31 V SUPPLY
CHECK - 26V SUPPLY
AIL
CHECK TI AND LINE
FILTER COMPONENTS
0
CHECK AMPLITUDE
CONTROL INTEGRATOR
CHECK BUFFER AMPLIFIER
O
'ss
BALANCED AMPLIFIER OUTPUT
AT TOP OF A2R74 AND BOTTOM
OF A2R75
4V "! 0.5V P- P
PASS
CHECK AC INPUT TO
CHECK AC INPUT TO
ATTENUATORS ( S4)
IMEDANCE SWITCH ON A4
GREATER SIGNAL
FA,
LESS
SIGNAL
FAIL
DETECTOR AMPLIFIER
C OF A2025 6-8V DC
PASS
PAS
CHECK BALANCED AMPLIFIER
CHECK IMPEDANCE
SWITCH ON A4
C)
CHECK ATTENUATORS
54
DETECTOR AMPLIFIER
C OF A2025 « 0.13V P- P
PASS
qD
DETECTOR VOLTAGES
OV ± 0.05V DC AT
A2 PINS BAND?
GREATER SIGNA
A2 PIN 6
NCORRECT
CHECK METER
AMPLIFIER AND
CURRENT SOURCE
CHECK AMPLITUDE
CONTROL INTEGRATOR
A L
ESS SI GNA
NOTES
CHECK DETECTOR DIODES
CHECK DETECTOR
AMPLIFIER
A2024 AND A2025
I. When using the troubleshooting tree, set the 654A controls as follows:
FREQUENCY dial
FREQUENCY RANGE
X1K
OUTPUT LEVEL dBm
+ 10,0
IMPEDANCE
50 UNBAL
AMPLITUDE
fully clockwise
2. Refer to Paragraph 5-77 at each step of the tree.
3. It is important to perform the front panel checks of Paragraph 5-74 before
using this troubleshooting tree.
Figure 5-18. Troubleshooting Tree.
5-27/5-28
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