HP 400D Organizational, Ds, Gs, And Depot Maintenance Manual

TM 11-6625-1514-15
Section I
Paragraphs 1-1 to 1-5
1-1. INTRODUCTION. (See figure l-l. )
1-2. This manual contains operating and servicing
instructions, and a parts breakdown, for the Models
400D, 400H, and 400L Vacuum Tube Voltmeters manu-
factured by the Hewlett- Packard Company. The Model
400D Voltmeter is similar to a military counterpart,
Electronic Voltmeter ME-30A/U, in appearance and
operation, but contains modified electrical circuits
to obtain improved performance. Applicable Federal
Stock Numbers for the voltmeters are as follows:
Model 400D: 6625-643-1670
Model 400H: 6625-557-8261
Model 400L: 6625-729-8360
1-3. The Models 400D, 400H, and 400L Voltmeters
are the same except for the differences listed in Fig-
a. The front panel meters are different in each
model, as described in paragraph 1-6.
b. The accuracy specifications are different for
each model, as described in figure 1-2.
1-4. DESCRIPTION.
1-5. The Hewlett-Packard Models 400D, 400H, and
400L Vacuum Tube Voltmeters are general purpose,
portable electronic a-c voltmeters of high sensitivity
and stability. They are suited to both laboratory and.
field use. Models 400 D/H measure a-c voltages from
0.001 to 300 volts and Model 400L from .003 to 300
volts rms full scale, with a frequency bandwidth cover-
ing 10 cps to 4 megacycles. The voltmeters are com-
pact, accurate, and rugged and have fast meter re-
sponse, high input impedance, stable calibration ac-
curacy, and freedom from the effects of normal line
voltage variations.
The voltmeters are designed for
—
ure 1-2.
long instrument life with a minimum of servicing.
a. Voltage Range: 400D/H - 0.1 millivolt to 300
g. Accuracy: Model 400D -
volts; 400L - 0.3 millivolt to 300 volts, in 12 ranges
providing full-scale readings of the following voltages:
± 2% of full scale, 20 cps to 1 mc;
± 3% of full scale, 20 cps to 2 mc;
0.001 0.100
10.00
± 5% of full scale, 10 cps to 4 mc.
0.003 0.300 30.00
0.010
1.000
100.00
Model 400H -
0.030 3.000
300.00
± 1% of full scale, 50 cps to 500 kc;
b. Decibel Range: -72 to +52 db, in 12 ranges.
± 2% of full scale, 20 cps to
1 mc;
± 3% of full scale, 20 cps to
2 mc;
c. Frequency Range: 10 cps to 4 mc.
+ 5% of full scale, 10 cps to
4 mc.
Model 400L -
d. Input Impedance: 10 megohms shunted by 15 pf
(15 µµf) on ranges 1.0 volt to 300 volts; 25 pf on ranges
±2% of reading or ±1% of full scale,
0.001 volt to 0.3 volt.
whichever is more accurate,
50 cps to 500 kc.
e. Stability: Line voltage variations of ±10% do not
±3% of reading or ±2% of full scale,
reduce the specified accuracy, and line voltage transients
whichever is more accurate,
are not reflected in the meter reading. Electron tube
20 cps to 1 mc.
deterioration to 75% of normal transconductance affects
±4% of reading or ±3% of full scale,
accuracy less than 0.5% from 20 cps to 1 mc.
whichever is more accurate,
20 cps to 2 mc.
±5% of reading 10 cps to 4 mc.
f. Amplifier: OUTPUT terminals are provided so
that the voltmeter can be used to amplify small signals
h. Power Requirement:
115/230 volts ±10%, 50 to
or to enable monitoring of waveforms under test with
1000 cps, approximately 100 watts.
an oscilloscope. Output voltage is approximately 0.15
volt rms on all ranges with full-scale meter deflection.
i. Size: 11-3/4 in. high, 7-1/2 in. wide, 12 in. deep.
Amplifier frequency response is same as the voltmeter.
Internal impedance is approximately 50 ohms over
j. Weight: 18 lbs; shipping weight approximately
entire frequency range.
23 lbs.
Figure 1-2. Table of Specifications
00102-3
1-1

HP 400D Specifications

General

Brand	HP
Model	400D
Category	Measuring Instruments
Language	English