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(5)
Refer to Table 4.3 below, and using the multimeter, measure the d.c.
voltages (to chassis) at the test points on the Power Stabiliser Board
19-0433, adjusting the appropriate potentiometers to obtain the
requ ired readings •
TABLE 4.3
Power Supply Check
Test Point
D. C. Voltage
Potentiometer
Adjustments
25
+12V ± O.lV
R8
28
+5V ± O.lV
R16
29
-5 AV ± O.lV
R22
30
12V ±O.lV
R30
(6)
If the check in (5) has been made with the plug-in p.c.b. assemblies
removed from the instrument, these should now be inserted and the
check in Table 4.3 repeated.
GENERAL PERFORMANCE CHECK
Frequency, Range, Output and Sensitivity
4.5
(1)
Set the SENSITIVITY switch to O. 01V.
(2)
Connect the signa I generator output to the INPUT of the instrument.
(3)
Terminate the
~
100 output socket with 50 ohms.
(4)
Switch on the instrument and with 10 mV r.m.s. applied from the signal
generator, check with a digital counter that division by 100 occurs at
the;' 100 output, over the frequency range 10 MHz to 500 MHz.
(5)
With the input as in (4) above check with an osci Iloscope that the f 100
output level is approximately 1.2V peak-to-peak over the frequency
range.
(6)
Repeat operations (4) and (5) over the frequency range 500 to 600 MHz
but with an input level of 100 mV r.m.s.
(7)
Transfer the 50 ohm load to the
7
10 output and check that the
~utput
level of approximately 1.2V peak-to-peak is obtained. (Make
~his
spot
check at the higher end of the frequency range).
901 0-9013
4 - 3
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