HP 400F, Operating And Service Manual, Page: 23 / 54

ModeI 400F/FL Section V
Paragraphs
5-16
to 5-20 and Figure 5-2
VTVM CALIBRATION SYSTEM
hp
K02 -73eBR
OSCILLATOR
hp
200SR
FREQUENCY RESPONSE
TEST SET
hp
739AR
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400F/FL
AC VOLTMETE
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VOLTMETER CALIBRATOR
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Figure 5-2. Alternate Accuracy and Frequency Response Check Setup
d_ Set 400F/FL RANGE switch to 100 my.
1) 400F should indicate 30 mv ±2%.
2) 400FL should indicate 30 mv ±1%.
e. Set 400F/FL RANGE switch to O. 3 volts.
1)
400F should indicate 30 mv ±5%.
2) 400FL cannot be checked with a
1/10
scale input.
!.
Adjust test oscillator (or a 400F/FL meter
indication of 30 mv at 1 MHz.
g. Set 400F/FL RANGE switch to 100 mv.
1)
400F should indicate 30 mv ±2%.
2) 400FL should indicate 30 mv :1%.
h. Set 400F/FL RANGE switch to O. 3 volts.
1)
400F should indicate 30 mv :5%.
2) 400F/FL cannot be checked with a 1/10
scale input.
5-16. INPUT IMPEDANC E CHECK.
5-17. INPUT RESISTANCE CHECK.
a. Connect the 50 0 output
of
the test oscillator
to 400F/FL.
b. Set 400F/FL RANGE switch to
1
volt_
c. Set test oscillator output for full scale deflec­
tion of 400 F / FL.
d. Connect a 100 K
n
resistor between test os­
cillator and 400F/FLas shown in Figure 5-3.
01795-1
e. 400F/FL meter indication should not drop
more than one small scale division from full
scale. This verifies an input resistance
of
10 M O.
5-18. INPUT CAPACITY CHECK.
a. Connect test oscillator and a 100 K
0
resistor
t0400F/FL as shown in Figure 5-3. Connect
the resistor lead directly to the GR connector.
b. Set 400F/FL RANGE switch to
1
volt.
c. Set test oscillator output for full scale deflec­
tion of 400F/FL meter at 400 Hz.
d. Increase frequency of test osclllator until
400F/FL indication drops toO. 707 volts. This
should occur at a frequency
of
150 KHz or
greater. verifying an input capactty of
1
0
pf
or
less on the
1
volt range.
e. Set 400F/FL RANGE switch to 300 my . .
!.
Set frequency response test set output for full
scale deflection
of
400F/FL meter at 400 Hz.
g. Increase frequency of test oscillator until
400F/FL indication drops to
212
my. This
should occur at a frequency of 60 KHz or
greater, verifylngan Input capacity of
25
pr or
less on the 300 mv range.
5-19. A L I G N M E N T A N D C A L I B R AT I O N
P R O C E D U R E S .
5-20. The Alignment and Calibration Procedures should
be performed only if it has been determined by the
Performance Checks that the 400F/FL is not within
5-3