EG&G ORTEC 463 Посібник з експлуатації та обслуговування - Сторінка 11

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Table 6.1. Typical Voltages at Suggested Check Points
Check Point
Voltage
Check Point
Voltage
Q1E
-0.658
IC3, pin 7
+1.622
Q1B
-0.002
IC3, pin 8
+10.78
Q2E
-0.663
IC4, pin 8
-0.756
Q2B
-0.008
IC4, pin 9
-1.646
IC1, pin 3
-1.110
IC4, pin 12
-0.937
IC1,pin4
-1.327
IC4, pin 13
-1.414
IC1, pin 1
-1.749
IC5,pin 11
-1.026
IC1, pin 2
-0.709
IC5, pin 3
-1.937
IC1, pin 8
-1.756
IC5, pin 4
-0.947
Q3E
-0.671
IC5, pin 1
-1.158
Q3B
-0.009
IC5, pin 2
-1.412
Q4E
-0.673
IC5, pin 6
-1.024
Q4B
-0.009
Q10E
-2.704
IC2, pin 1
-1.149
Q10B
-1.933
IC2, pin 2
-1.146
Q18E
-2.705
IC2, pin 12
-1.179
Q12B
-0.120
IC2, pin 13
-1.146
Q12C
+3.509
IC2, pin 8
-1.124
Q13B
-0.344
Q5E
-12.61
Q14E
+2.729
Q6E
-12.00
Q15B
+0.651
Q6B
-11.35
Q15C
+0.428
Q8E
-10.70
Q17E
-5.875
Q8B
-16.59
Q17B
-6.504
Q8C
-10.69
Q17C
-10.82
Q9E
+0.647
-6
-5.547
IC3, pin 3
-1.147
-6d
-5.306
IC3, pin 4
-6.183
The width should be <10 nsec and the amplitude should
be >0.7 V into a 50f2 load. A slow oscilloscope wil l
distort both the amplitude and the width.
Move the oscilloscope connection to observe the Neg out
put nearer the bottom of the front panel. Repeat the
above procedure and adjust R53 (nearer the bottom on
the printed circuit board) for the optimum signal through
this output.
6.4. WALK ADJUSTMENT
If the 463 is suspected of having excessive walk, test it for
conformance to operating standards with the following
steps. The tests are outlined separately for each of the 3
operating modes of the 463.
Ge(Li) Mode Figure 6.1 shows a system tfiat can be used
to check the 463 walk in the Ge(Li) mode. A slow
rise-time pulse, 'VIOO nsec, with a maximum amplitude of
about -10 V is applied to the 463 Input. When the Neg
output is observed, it should not move more than +2 nsec
with respect to the trigger applied to the oscilloscope for
any combinations of XI, X2, X5, and X10 attenuator
settings on the 448 Pulser.
Scint/SB Mode Use the system shown in the block diagram
of Fig. 6.2 to test the walk of the 463 in its Scint/SB mode.
ORTEC
448
RESEARCH PULSER
Negative Polarity
RG-58 Cable
Direct Output
loon
Attenuated Output
ORTEC
454
TIMING FILTER AMPLIFIER
Coarse Gain:
5
Fine Gain:
2
lot:
100 nsec
Diff:
100 nsec
Input Polarity: Neg
TEKTRONIX
454
OSCILLOSCOPE
0.5 V/div
5 nsec/div
Ext Trigger
ORTEC
463
CONSTANT FRACTION
DISCRIMINATOR
Shaping Mode: Ge(Li)
Disc Level:
5 (minor div)
Fig. 6.1. Block Diagram of System for Walk Test of the
ORTEC 463 In the Ge(LI) Mode.
RG-58 Cable
RG-58 Cable
TRIGGER
50<>
TEKTRONIX
SO'i ATTENUATOR
X2, X5, X10
ORTEC
463
CONSTANT FRACTION
DISCRIMINATOR
Shaping Mode: Ge(Li)
Disc Level:
5 (minor div)
TEKTRONIX
454
OSCILLOSCOPE
0.5 V/div
5 nsec/div
Ext Trigger
Rep. Rate:
Pulse Width:
Amplitude:
Output Polarity: Neg.
1000
10 n
HP-8004 A
PULSER
sec
5 V
Fig. 6.2. Block Diagram of System for Walk Test of the
ORTEC 463 In the Scint/SB Mode.
For any combination of attenuator settings of XI, X2, X5,
and XI0 (but not for XI00) the observed walk should be
less than +0.15 of a minor division on the oscilloscope.
A more precise measurement can be made if a time base
of 1 nsec/division is available. This time base is available
on Tektronix 454A real time oscilloscopes and on sampling
oscilloscopes. A dynamic range of only 50:1 has been
suggested because the FIP8004A provides a maximum
output amplitude of 5 V. If a pulser is available with a