Geräte Informationen:

Faircild Instrumentation 74-13A Oszilloskop
Hersteller:
Faircild Instrumentation
Modell: 74-13A
Datum: 1965
Kategorie: Messgeräte
Gruppe: Oszilloskop
Beschreibung: Calibrated Delaying Sweep
Informationen:
                                    PLEASE NOTE

IMPORTANT INITIAL ADJUSTMENTS MUST BE MADE BEFORE OPERATING
THIS Plug-In MODULE. See Paragraph 21 entitled "First Time
Operation” in Section 2 for instructions.
The Type 74-13A Dual Time Base Calibrated Delaying Sweep is
designed for use with the Fairchild Type 765/765H Series of
Transistorized Oscilloscopes.

To simplify circuit description, the following abbreviations
are employed to describe the Dual time base delaying sweeps.
Abbreviation	Description

NDT The NDT sweep refers to Normal Sweep operation and
Delaying Triggered operation (i.e., the delayed sweep starts
immediately after the delay pick-off trigger is generated).

DA The DA sweep refers to Delayed Armed operation (i.e., the
delaying sweep (NDT) generates a delay pick-off trigger
which arms the DA sweep). An input trigger signal is then
required to fire the DA sweep.

1-2. TECHNICAL SUMMARY

The performance specification of this Plug-In module is
given in the technical summary which follows.

TIME BASE SYSTEM Calibrated Sweep Range (NDT & DA)

Calibrated linear sweep rates from 0.1 /¿sec/div to 2
sec/div in 23 steps of 1, 2, and 5 sequence

Uncalibrated Sweep Range

The Sweep Vernier control provides a continuous uncaiibrated
range of sweep rates between ranges and extends the 2
sec/div range to 5 sec/div (50 seconds full scale). The
UNCAL lamp serves as an indicator of uncaiibrated or vernier
operation

Sweep Accuracy

±3% measured over the centered 8 div portion of the CRT screen

Sweep Range Indicator

Push-pull clutch knob permits simultaneous or independent
control of the NDT and DA sweep rates

Sweep Expander

A calibrated XI0 sweep expander in the X output Amplifier
will expand the sweep about screen center; extends fastest
sweep rate to 10 nano-seconds/div. Expander accuracy is ±5%
for speeds faster than 200 nanoseconds/div and ±3% for
slower sweeps. Neglect the first 50 nanoseconds

Sweep Calibration

A front-panel screwdriver SWP CAL control Is provided to
permit normalization of the Plug-In unit to the Main Frame
and standardizing the sweeps to an external time standard

Gate Out (NDT & DA)

Two front-panel banana ¡acks each provide a positive-going
pulse of 2.5 volts nominal. Output impedance is 500 ohms.
For optimum performance, load impedance should be greater
than 100K ohms and shunted by less than 15 pf. Gate is
referenced directly to ground and is time-coincident with
the sweep

Saw

Panel banana jack provides a positive saw output of
approximately 25 volts and is coincident with the NDT Sweep.
Output impedance is nominally 1 OK ohms, and load impedance
should be greater than 100K ohms shunted by less than 15 pf

Other Controls

Internal controls optimize settings of automatic strobe
intensity and strobe transition. This normalizes the Plug-In
to the CRT of the Main Frame and avoids having to reset the
intensity control when observing strobed display modes
SWEEP MODES

Normal Sweep Operation

Conventional sweep display. Internally or externally applied
trigger signals drive the NDT time base circuit

Delayed-Triggered Strobe

Delaying sweep display showing the delayed sweep as a
brightened sector. The delayed sweep starts immediately
after the delay pick-off trigger is generated

Delayed-Armed Strobe

Delaying sweep display showing the delayed sweep as a
brightened sector, but delayed sweep (brightened sector) is
armed by the delayed trigger and initiated by a sync trigger

The delayed sweep automatically shuts off when the delaying
sweep is terminated. This prevents brightening of the sweep
retrace in either STROBE position

Delayed Triggered or Delayed Armed

The brightened sector of the strobe sweep displays are
expanded to full scale in either of the DELAYED modes.
Automatic provision is made for shut-off of the delaying
sweep (NDT) when the delayed sweep (DA) is terminated. This
permits maximum duty cycle performance in the DELAYED mode

Single Sweep

The single sweep mode permits but one driven sweep of the
time base to appear on the screen until the delayed sweep
(DA) is reset or rearmed

The single sweep may be rearmed with a single external
trigger pulse, by turning the NDT Trigger Level control or
by switching the NDT trigger polarity switch

The SWP READY indicator is lit whenever the delayed sweep
gate multivibrator is armed and ready to be triggered

X Amplifier (for X-Y Displays)

When the DISPLAY LOGIC switch is set to X AMP, X Input
signals may be applied to X Amplifier via EXT setting of the
Trigger SOURCE switch and preferably " — Slope"

CALIBRATED DELAY TIME SYSTEM

Delay Vernier Control

A ten-turn precision potentiometer determines the on-screen
distance from the delaying sweep (NDT) start at which the
delayed sweep is either triggered or armed

CALIBRATED DELAY TIME SYSTEM (Concluded)

The DELAY VERNIER control is calibrated to read from zero to
1 0 divisions. This control functions as a Delay Multiplier
when used in conjunction with the Delayed TIME/D IV control

Accuracy

Incremental accuracy of the ten-turn calibrated control is
within ±0.25%

Delay Zero Control

Zero delay is adjustable from the front panel. For extreme
accuracy, any or all steps can be adjusted to an external
standard from the front panel

Delay Range

From a minimum of '/4 microsecond to more than 20 seconds

TRIGGERING SYSTEM (Separate facilities for each Time Base
are provided)

HF Recur

A unique high-frequency stability switch may be used to
improve count down and lock-in of signals having repetition
rate of 5 Me or greater. It provides stable synchronization
of signals of 1 cm deflection to beyond 50 Me
Internal Trigger

Signals will trigger from 0.5 div of Y signal up to 1 Me;
from 1 div of Y signal up to 10 Me with Types 76-01 A,
76-02A, 76-03 and 76-08 Modules in Y cavity. With the HF
STAB control set to RECUR, adjustment of the Trigger LEVEL
and HF STAB controls will produce a stable display with 0.2
division of Y signal at 1 Me and 2 divisions of Y signal at
30 Me

External Trigger (XI)

0.5 volt peak-to-peak from dc to 1 Me will trigger the
sweep; 1 volt peak-to-peak will trigger the sweep to 10 Me.
Trigger leveling, slope selection and ac or dc coupling are
included. With the HF STAB control set to RECUR, adjustment
of the Trigger LEVEL control will produce a stable display
with 0.2V to 10V input at 1 Me

External Trigger (X10)

Same frequency limits as external trigger XI; a 10:1
attenuator is provided to extend the dc leveling capability
to ±100 volts dc

Trigger Level

A range of ±10 volts (nominal) with respect to ground on
external triggering
Trigger Slope

Selection of positive or negative slopes on Internal, Line,
or External triggering is available

Line Trigger

Line frequency triggering can be selected in either polarity
and the triggering point may be shifted with the Trig LEVEL
control

Ext Trig Input Impedance

1 megohm shunted by 40 pf (nominal)

AC Coupling

High-pass filter with low-frequency cutoff of 80 cycles

DC Coupling

Direct coupling is provided to optimize trigger sensitivity
when very slow waveforms are applied; to maintain the
initial reference position of the trace with respect to the
CRT scale at a given trigger level setting; and to avoid
trigger point variations due to random repetition rate
trigger signals

ACF

Differentiated trigger input; high-pass filter is provided
to reject hum and low-frequency amplitude modulation;
low-frequency cutoff nominally 10 Kc. Signals should rise or
fall in less than 100 /¿sec to pass the LF reject filter

Automatic Triggering

Visible base line on all sweep ranges when there is no
signal input. The sweep free runs until a trigger signal of
10 cps to 10 Me is applied. Application of a trigger signal
switches the sweep to the triggered mode immediately

HORIZONTAL DEFLECTION SYSTEM Bandwidth

Direct Coupled: DC to 2 Me; down 3 db at 2 Me

Capacitively Coupled: Low-frequency cutoff is 80 cycles

Sensitivity (XI0 Expansion)

EXT/X1 Range: 0.1 volt/div EXT/X10 Range: 1 volt/div

X Vernier: A ten-to-one attenuator is provided in the
horizontal deflection channel to extend the input signal
range to 10 volts/div

Sensitivity (XT Expansion)
Reduces all above sensitivities by 10:1 (Restricted scan)	

HORIZONTAL DEFLECTION SYSTEM (Concluded) Input Impedance

1 megohm shunted by 40 pf (nominal)

Input Connector

X AMR front-panel connector is provided to permit use of the
horizontal deflection Amplifier for X-Y displays. (DA EXT
TRIG connector serves this Dual purpose)
X Positioning	'

A front-panel control permits coarse and fine positioning of
the X Input signal or any portion of the sweep to within two
divisions of screen center

Beam Position Indicator*

Two indicator lamps are located on the front panel to alert
the operator as to the direction of the beam when it is
positioned off the screen

Folgende Anleitungen sind hier verfügbar:

Dokumenttyp: Service- und Bedienungsanleitung Fairchild-8991-Manual-Page-1-Picture
Seitenanzahl: 80
Dateigröße: 4.00 Mbytes (4189174 Bytes)
Sprache: Englisch
Revision:
Dokument-ID/Nummer: 67043234
Datum: 01 Januar 1965
Qualität: Gescanntes Dokument, teilweise schwer oder teilweise nicht zu lesen.
Upload Datum:
MD5: 3d4b17c45967a35e0849be7e2bb75a8d
Downloads: 95 seit dem 07 Mai 2017
Informationen:
1.	TECHNICAL SUMMARY

-	1.3

1-] Introduction
 ... - ... ; ... 

1-2	Technical Summary (Specifications)  ... 

2.	OPERATING INSTRUCTIONS

2-1	First Time Operation
 ...  2-1

2-2	Sweep
Triggering ... 
f

2-5	Trigger Source
Selection ... 

2-4	Trigger Coupling Selection  ... 

2-5	Trigger Slope
Selection ... 

2-6	Trigger Level
Selection ... 

2-7 Sweep Operational Modes
 ...  ¿-JO

2-8 Sweep Expander ... 
 ...  2-11

2-9 Sweep Calibration Adjustment  ...  £-11

2-10 X-Y Displays
 ... 
2-12

2-11 Gate Output
 ... 

2-12 Sawtooth Output
 ... 

2-13 Time Measurements
 ... 

2-14 Phase-Shift
Measurements ... - ...  *'15

2-15 Pulse Width Measurements Using

the CRT Scale
 ... : ...  215

2-16 Pulse Width Measurements Using

the Delay Vernier Control ...  2-14

2-17	Pulse Jitter Measurements
 ...  2-14

3.	CIRCUIT DESCRIPTION

3-1	Introduction
 ... 

3-2 Trigger Circuit Description  ... 

3-3 Circuit Description of Normal Sweep ...  3-3

3-4 Circuit Description of Triggered-

Strobe Mode
 ... 

3-5 Circuit Description of Delayed-

Triggered Mode
 ...  3-8

3-6 Circuit Description of Armed-

Strobe Mode
 ... 
3-8

3-7 Circuit Description of Delayed-

Armed
Mode ... 
3-10

3-8	Horizontal Deflection Circuit

Description
 ... 
3-10

4.	PERFORMANCE ASSURANCE TEST

4-1	Maintenance Check to Assure

Performance ... 

4-2 Checking Sweep Calibration  ...  4-1

4-4 Checking Normal, Triggered and

Armed Sweep Displays ...  4-2

4-5 Delay Calibration Check
 ...  4-2

4-6 NDT Gate Out Check
 ...  4-2

4-7 NDT Saw Out Check
 ...  4-2

4-8 Dual Trace Switch Triggering Check ...  4-2

4-9 Beam Positioning Indicator Check ...  4-3
Section	Title	P°Se

5.	MAINTENANCE AND RECALIBRATION

5-1 Introduction
 ... 
•>'}

5-2 Removal and Replacement of Parts ...  5-1

5-3 Servicing Hints
 ...  jj-l

5-4 Gaining Access to Chassis ... 

5-5 Test Equipment Required for Service

Adjustments
 ... 

5-6 NDT & DA Trig Sens Adjustment ...  o-i

5-7 Trig Bal Adjust
 ... - ...  5-3

5-9 NDT Sweep Length Adjustment  ...  5-3

5-11 DA Sweep Length Adjustment ...  5-3

5-12 Sweep Rate Bal Adjustment  ...  5-5

5-13 X10 Registration
 ...  54

5-14 X Amplifier High-Frequency

Adjustment
 ... 
£-4

5-15 X Ampl DC Balance Adjustment  ...  5-4

5-16 Fast Sweep Calibration Adjustment ...  5-&

5-17 Strobe Intensity and Pattern

Correction Adjustment  ...  o-5

5-18 Delay Zero Adjustment
 ...  5-5

5-19 Delay Cal
Adjustment ... 

6. PARTS LISTS AND SCHEMATICS

6A Electrical Parts List
 ...  6-1

6B Spare Parts List
 ...  “-7

List of Recommended Vendors ...  6-9

CHART

Sweep Check Calibration Chart ...  4-2
Fairchild-8991-Manual-Page-1-Picture


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