Home
HP
Measuring Instruments
412A
HP 412A User Manual
5
of 1
of 1 rating
40 pages
Give review
Manual
Specs
To Next Page
To Next Page
To Previous Page
To Previous Page
Loading...
List
of
Illustrations
n
n
Number
1-1.
Model
412A
DC
Vacuum
Tube
Voltmeter
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
4-1.
Block
Diagram
.
.
.
.
.
.
.
.
.
.
.
.
.
.
5-1.
Input
Resistance
Check
.
.
.
.
.
.
.
.
5-2.
AC
Rejection
Check
.
.
.
.
.
.
.
.
.
.
53.
Location
of
Adjustments
.
.
.
.
.
.
54.
Input
Circuit
Board
.
.
.
.
.
.
.
.
.
.
.
5-5.
Modulator
Waveform
.
.
.
.
.
.
.
.
.
54.
Demodulator
Assembly
.
.
.
.
.
.
.
.
5-7.
input
Cable
Connections.
.
.
.
.
.
.
5-8.
Simplified
Schematic,
Voltmeter
Switching
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
5-9.
Simplified
Schematic,
Ammeter
Switching
.
.
*
.
.
.
.
.
.
.
.
.
,
.
.
.
.
.1
t,p’
8
LIST
...........
...........
...........
...........
...........
...........
...........
...........
...........
...........
.....e.....
’
OF
ILLUSTRATIONS
Page
Number
,
.
,
1-1
,
.
,
4-1
.
.
.
5-2
..
.
53
...
54
...
56
.
..
5-7
...
s-8
...
59
.
.5-10
.
.
.5-11
5-1O.Simplified
Schematic,
Ohmmeter
Switching
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
6-1.
Location
of
Mechanical
Parts,
Cabinet
Model
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
6-2.
Location
of
Mechanical
Parts,
Rack
Model
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
6-3.
Voltage
Probe
Assembly
.
.
.
.
.
.
.
.
.
7-1.
Location
of
Chassis
Mounted.Parts,
Cabinet
Model
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
7-2.
Location
of
Chassis
Mounted
Parts,
Rack
Model
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
7-3.
Location
of
Switch
Components
.
.
.
74.
Schematic
Diagram
.
.
.
.
.
.
.
.
.
.
.
.
.
7-5
Power
Supply Backdating
.
.
.
.
.
.
.
.
Model
4
12A
..........
..........
..........
..........
..........
e.........
..........
..........
..........
Page
.
.5-I
2
.
.
6-5
.
.
6.6
.
.
6-7
.
.
7-2
.
.
7-3
..
74
.
.
7-5
.
.
7-7
3
5
Table of Contents
Table of Contents
3
General Information
6
Introduction
6
Instrument and Manual Identification
6
Introduction
7
Initial Inspection
7
Power Requirements
7
Repackaging for Shipment
7
Introduction
8
Low-Level Electrical Phenomena
8
Voltage Measurement
8
Current Measurement
8
Resistance Measurement
9
Amplifier Operation
10
General
11
Range and Function Selection
11
Filters
11
Modulator. Amplifier. Demodulator
11
Power
12
Maintenance
13
Required Test Equipment
13
Performance Checks
13
Voltmeter Accuracy Check
13
Ohmmeter Accuracy Check
14
Input Resistance Check
14
Adjustment and Calibration Proccdure
15
Cabinet Removal
15
Mechanical Adjustment of Meter Zero
15
Location of Adjustments
16
Hum Balance Adjustment
17
Cathode Follower Bias Adjustrncnt
17
Meter Electrical Zero Adjustment
17
Amplifier Gain Adjustment and Meter Calibration
17
Troubleshooting
18
Front Panel Indications
18
Power Supply and Amplifier Checks
18
Modulator Clieck
18
Modulator Replacement
19
Demodulator Check
19
Demodulator Replacement
20
Switch Checks
20
Components
20
Demodulator Assembly
20
Cabinet Model
20
Rack Model
20
Simplified Schematic, Voltmeter
21
Simplified Schematic, Ammeter
22
Meter Zero
24
AC Rejection Check
25
Replaceableparts
26
Non-Listed Parts
26
Mechanical Parts
30
Location
31
Location of
34
Other manuals for HP 412A
Manual
4 pages
5
Based on 1 rating
Ask a question
Give review
Questions and Answers:
Need help?
Do you have a question about the HP 412A and is the answer not in the manual?
Ask a question
HP 412A Specifications
General
Brand
HP
Model
412A
Category
Measuring Instruments
Language
English
Related product manuals
HP 416A
109 pages
HP 415E
59 pages
HP 410C
64 pages
HP 4194A
4 pages
HP 4195A
55 pages
HP 4145A
269 pages
HP 4145B
187 pages
HP 4155A
279 pages
HP 400E
57 pages
HP 400FL
54 pages
HP 4934A
136 pages
HP EPM-441A
158 pages
To Next PageTo Next PageTo Previous PageTo Previous Page
Loading...
Need help?
General
