Tektronix 5A15N User manual

INSTRUCTION |
| MIARNIUAL | Serial Number
|
Tektronix, Inc. @ P. O. Box 500 @ Beaverton, Oregon 97005 @ Phone [phone] @ Cables: Tektronix
070-1136-00 871

7 be reproduced in any form without permission of the
Copyright © 1971 by Tektronix, Inc., Beaverton, |
_ Oregon. Printed in the United States of America. All
- rights reserved. Contents of this publication may not
copyright owne
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TABLE
OF
CONTENTS
|
Page Page
SECTION
1
SPECIFICATION
SECTION
4
CALIBRATION
(cont)
Introduction 1-1 Services Available 4-1
Table 1-1, Electrical Characteristics | | Test Equipment Required 4-1
Calibration Equipment Alternatives 4-2
| Special Calibration Fixtures 4-2
SECTION
2
OPERATING
INSTRUCTIONS
|
Test
Instruments
4-2
Introduction 2-1 Accessories +2
Plug-In
Insertion
and
Removal
2-1
Short-Form
Procedure.and
Index
4-2
Controls and Connectors 2-1 Calibration Procedure | 4-2
Basic Operation | 2-1
— Preparation | 2-1
Step Attenuator Balance 2-2 SECTION 5 PARTS LISTS AND DIAGRAMS
Gain
Check
22
Symbols
and
Reference
Designators
5-1
General Operating Information 2-2 Parts List Abbreviations 5.2
Applying Signals a2 Schematic Diagrams
a
Input
Coupling
2-2
Component
Board
Locations
( Deflection Factor 2-3
Electrical Parts List
Mechanical Parts List
SECTION 3 CIRCUIT DESCRIPTION
Introduction 3-1 CHANGE INFORMATION
Plug-In Logic 3-1
Input Coupling 3-1
Input Attenuator 3-1
Amplifier 3-1
Abbreviations and symbols used in this manual are based on
or taken directly from IEEE Standard 260 “Standard
Symbols for Units’, MIL-STD-12B and other standards of
Introduction 4-1 the electronics industry. Change information, if any, is
SECTION 4 CALIBRATION
Instrument Maintenance 4-1 located at the rear of this manual.

5A15N
Fig. 1-1. 5415N Amplifier.
eo

5A15N
SECTION 1
SPECIFICATION
Change information, if any, affecting this section will be found at the rear of this manual.
Introduction
The 5A15N Amplifier is a general-purpose amplifier
plug-in unit for use with Tektronix 5100-series oscillo-
scopes. The unit features solid-state circuitry and simplicity
of front-panel controls, which include a lighted knob skirt
to provide a direct readout of calibrated deflection factor.
The 5A15N has calibrated deflection factors from one milli-
volt per division to five volts per division and a bandwidth
from DC to at least two megahertz. While designed pri-
marily for use as a vertical amplifier, the unit can be
operated in association with the horizontal deflection
system of the oscilloscope for X-Y displays.
The following electrical characteristics apply over an
ambient temperature range of OC to +50°C. Refer to the
5100-series Oscilloscope System manual for environmental
characteristics.
In this manual the word Volts/Div or division refers to
major graticule division.
TABLE 1-1
ELECTRICAL CHARACTERISTICS
Characteristic Performance Requirement
Supplemental Information
Deflection Factor
Calibrated Range
1 millivolt/division to 5 volts/division
12 steps in a 1-2-5 sequence
Accuracy
Within 2%
Step Attenuator Balance
Adjustable for one division or less trace
movement as VOLTS/DIV is rotated
throughout its range.
Uncalibrated (Var) Range
At least 2.5:1.
Frequency Response
Bandwidth (8 Div Reference)
DC (Direct) Coupled
DC to at least 2 megahertz.
AC (Capacitive) Coupled
2 hertz or less to at least 2 megahertz.
Step Response (Displayed)
Aberrations
+2% of pulse amplitude.
Inputs
Resistance
1 megohm, within 1%.
Capacitance
~47 picofarads
Time constant normalized for 47 micro-
seconds, within 3%.
Maximum Safe Input Voltages
DC (Direct) Coupled
350 V (DC + Peak AC)
AC (Capacitive) Coupled
350 VDC
| POSITION Range
At least + and —10 divisions fr6m grati-
cule center.
1-1

5AI5N
SECTION 2
OPERATING
INSTRUCTIONS
Change information, if any, affecting this section will be found at the rear of this manual.
Introduction
The 5A15N Amplifier Plug-in operates with a Tektronix
5100-series oscilloscope. An understanding of the 5A15N
Operation and capabilities is essential for obtaining best
results. This section of the manual gives a brief functional
description
of
the
front-panel
controls
and
connectors,
a
familiarization procedure, and general operating informa-
tion.
PLUG-IN INSERTION AND REMOVAL
The 5A15N is calibrated and ready for use as it is
received. It can be installed in any compartment of the
9100-series oscilloscope, but it is intended for principal use
in vertical compartments (the center and left compart-
ments). For X-Y operation, the 5415N may also be
installed in the horizontal (right) compartment (refer to the
5100N Oscilloscope System Instruction Manual for infor-
mation on X-Y operation).
NOTE
If the oscilloscope system receives no DISPLAY ON
logic levels from the vertical plug-ins, it is designed to
display the unit in the left compartment.
To install, align the upper and lower rails of the 5415N
with the plug-in compartment tracks and fully insert it (the
plug-in panel must be flush with the oscilloscope panel). To
remove, pull the release latch to disengage the 5A15N from
the oscilloscope.
CONTROLS AND CONNECTORS
This is a brief description of the function or operation of
the front-panel controls and connectors. More detailed
information is given under General Operating Information.
DISPLAY ON Applies and removes logic levels to
the oscilloscope system to enable or
disable plug-in operation. The
switch functions only when the
plug-in is operated in one of the
vertical plug-in compartments.
POSITION Positions display.
®
VOLTS/DIV Volts per major graticule division.
Selects calibrated deflection factors
from 1 mV/Div to 5 V/Div: 12
steps in a 1-2-5 sequence. Knob
skirt is illuminated to indicate de-
flection factor.
Variable
Volts/Div
Provides
uncalibrated,
continuously
variable deflection factor between
calibrated steps; extends range to
12.5 V/Div.
Balances the input amplifier for
minimum trace shift throughout
the VOLTS/DIV gain-switching
range.
STEP ATTEN BAL
AC-DC: Button pushed in selects
Capacitive coupling of input
signal; button out selects direct
coupling of input signal.
Input Coupling
Pushbuttons
GND: Disconnects the input signal
and provides ground reference to
the amplifier input stage.
PRE CHG: Both AC-DC and GND
buttons pushed in allows pre-
charging of the coupling capaci-
tor. Release GND for measure-
ment.
Input
Connector
BNC
connector
for
application
of
external voltage. signals. Includes a
coded-probe input ring for activa-
tion of X10 readout.
BASIC OPERATION
Preparation
The first few steps of the following procedure are
intended to help quickly obtain a trace on the screen and
prepare the instrument for immediate use. The remainder
of the steps demonstrate some of the basic functions of the
SAISN. Operation of other instruments in the system is
described in the instruction manuals for those units.
1. Insert the unit all the way into the oscilloscope
system plug-in compartment.
2. Turn the oscilloscope Intensity control fully counter-
clockwise and turn the oscilloscope system Power ON. Pre-
2-1

Operating Instructions—5A15N
set the time-base and triggering controls for a 2-millisecond/
division sweep rate and automatic triggering.
3. Set the 5A15N front-panel controls as follows:
DISPLAY ON (deflection factor
illuminated)
POSITION Midrange
VOLTS/DIV .1 V Calibrated
STEP ATTEN BAL Midrange
Input Coupling DC, GND
4. Adjust the Intensity control for normal viewing of
the trace. The trace should appear near the graticule center.
5, Move the trace two divisions below the graticule
centerline with the POSITION control.
6. Apply a 400-millivolt peak-to-peak signal (available at
the oscilloscope Calibrator loop) through a test lead or 1X
probe to the input connector.
7. Release the GND pushbutton. The display should be
square waves four divisions in amplitude, with the bottom
of the display at the reference established in step 5. Rotate
the Variable control throughout its range, observing a
reduction of the display amplitude. Return the Variable
contro! to the CAL detent (calibrated Volts/Div) position.
8. To demonstrate AC-coupled operation, re-position.
the display with the POSITION control to place the bottom
of the display at the graticule centerline.
9. Push in the AC button and note that the display
shifts downward about two divisions to its average level.
Step Attenuator Balance
If the STEP ATTEN BAL control is not properly
adjusted, the CRT zero reference point (trace or spot) will
shift vertically due to differential DC imbalance in the
amplifier as the VOLTS/DIV switch is rotated throughout
its range. The shift is more noticeable on the most sensitive
positions.
a. With the instrument operating, ground the input
(GND button pushed in) and set the VOLTS/DIV switch to
5 V. Move the trace to the graticule center with the POSI-
TION control. :
b. Rotate the VOLTS/DIV switch throughout its range
and adjust the STEP ATTEN BAL control for minimum
trace shift.
2-2
Gain Check
The vertical and horizontal deflection systems of the
5100N-series oscilloscopes are gain-standardized to permit a
plug-in to be moved from one oscilloscope to another (or
from one compartment to another within the oscilloscope)
without the need to recheck the calibration each time.
However, the 5A15N gain can be checked and, if necessary,
adjusted.
This completes the basic operating procedure for the
5AI5N. Instrument operations not explained here or those
that need further explanation are discussed under General
Operating Information.
GENERAL OPERATING INFORMATION
Applying Signals
When measuring DC voltage, use the largest deflection
factor (5 V/Div) when first connecting the 5A15N to an
unknown voltage source. If the deflection is too small to
make the measurement, switch to a lower deflection factor.
In general, probes offer the most convenient method of
connecting a signal to the input of the 5A15N. Tektronix
probes are shielded to prevent pickup of electrostatic inter- |
ference. A 10X attenuator probe offers a high input
impedance and allows the circuit under test to perform very
close to normal operating conditions. The 5A15N its
designed for compatibility with coded probes, such as the
Tektronix P6060 and P6052 Passive Probes. The input con-
nector has an outer ring to which the coding ring on the
probe connector makes contact. This type of probe allows
the vertical deflection factor indicated by the readout to
correspond with the actual deflection factor at the probe
tip, eliminating the need to consider the attenuation factor
of the probe when measuring the signal amplitude on the
graticule scale. See your Tektronix, Inc., catalog for charac-
teristics and compatibility of probes. for use with this
system. |
Sometimes unshielded test leads can be used to connect
the 5A15N to a signal source, particularly when a high-
level, low-frequency signal is monitored at a low-impedance
point. However, when any of these factors is missing, it
becomes increasingly important to use shielded signal
cables. In all cases, the signal-transporting leads should be
kept as short as practical. Be sure to establish a common
ground connection between the device under test and the
5A15N. The shield of a coaxial cable or ground strap of a
signal probe provides adequate common ground connec-
tion.
Input Coupling
The AC-DC pushbutton switch allows a choice of input
coupling. The type of display desired will determine the
coupling used.
—_—
ee
—
oe
—
Se
er

DC coupling (button out) can be used for most applica-
tions. However, if the DC component of the signal is much
_ larger than the AC component, AC coupling (button in)
will probably provide a better display. DC coupling should
be used to display AC signals below about 2 hertz as they
will be attenuated in the AC position.
In the AC position, the DC component is blocked by a
capacitor in the input circuit. The low-frequency response
in the AC position is about 2 hertz (—3 dB point). There-
fore, some low-frequency attenuation can be expected near
this frequency limit. Distortion will also appear in square
waves which have low-frequency components.
The GND pushbutton provides a ground reference at the
amplifier input. The signal applied to the input connector is
presented with a one-megohm load, while the amplifier
Input is grounded. This eliminates the need to externally
ground the input to establish a DC ground reference.
Pre-charging. To minimize surge currents in the circuit
under test when using deflection factors of 50 mV/Div
through 1 mV/Div and a 1X probe, use the AC-DC and
GND pushbuttons to take advantage of the pre-charging
circuit incorporated inthe unit. The pre-charging circuit
permits charging the coupling capacitor to the DC source
voltage when the AC and GND buttons are pressed in. The
procedure for using this circuit is as follows:
Operating Instructions—5A15N
a. Before connecting the 5A15N to a signal containing a
DC component, push in the AC and GND buttons. Then
connect the input to the circuit under test.
b. Wait about one second for the coupling capacitor to
charge. |
c. Remove the ground from the coupling capacitor
(GND button out). The display will remain on-screen and
the AC component can be measured in the usual manner.
Deflection Factor
The amount of trace deflection produced by a signal is
determined by the signal amplitude, the attenuation factor
(if any) of the probe, the setting of the VOLTS/DIV
switch, and the setting of the Variable control. The cali-
brated deflection factors are indicated by the VOLTS/DIV
switch only when the Variable control is rotated fully
clockwise into the detent position.
The range of the Variable control is at least 2.5:1. It.
provides uncalibrated deflection factors covering the full
range between the fixed settings of the VOLTS/DIV switch.
The control can be set to extend the deflection factor to at
least 12.5 volts/division.
2-3