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TEKTRONIX
7L13
SPECTRUM
ANALYZER
INSTRUCTION MANUAL
Tektronix, Inc.
P.O . Box 500
Beaverton, Oregon 97005 Serial Number
070-1673-00 First Printing APR 1974
WARRANTY
All TEKTRONIX instruments are warranted against
defective materials and workmanship for one year.
Any questions with respect to the warranty, should
betaken up with yourTEKTRONIX Field Engineeror
representative .
All requests for repairs and replacement parts
should be directed to the TEKTRONIX Field Office
or representative in your area. This will assure you
the fastest possible service . Please include the
instrument Type Number or Part Number and Serial
Number with all requests for parts or service .
Specifications and price change privileges reserved .
Copyright c 1974 by Tektronix, Inc ., Beaverton,
Oregon . Printed in the United States of America . All
rights reserved . Contents of this publication may not
be reproduced in any form without permission of
Tektronix, Inc .
U .S.A . and foreign TEKTRONIX products covered
by U .S. and foreign patents and/or patents pending .
TEKTRONIX is a registered trademark of Tektronix,
I
TABLE OF CONTENTS
SECTION 1 GENERAL INFORMATION & SPECIFICATIONS Page
Electrical Characteristics 1-2
Environmental Characteristics 1-4
Accessories
SECTION 2 OPERATING INSTRUCTIONS
Introduction 2-1
Function of the Front Panel Controls .
Operational Check 2-5
Using the Analyzer 2-9
Signal Application
Resolution, Sensitivity, and Frequency Span 2-10
Gain Desensitization Near 0 Hz 2-11
Using the Video Filter
Selecting Sweep Rate
Triggering the Display 2-12
Manual Scan of the Spectrum
How to Use an External Sweep Source
External Trigger Operation
Using the CAL OUT Signal Reference for Accurate
Frequency and Amplitude Measurements 2-13
Using the Analyzer Below 100 kHz 2-14
SECTION 3 PERFORMANCE CHECK
Operational Performance and Instrument Familiarization 3-1
Equipment Required
Preliminary Preparation
Check the 10 dB/Div and LIN Mode Calibration
Check the Frequency Readout Accuracy 3-2
Check the Range of the REF VAR Control, the
Range and Accuracy of the Gain Selector, and
the Gain Accuracy of the 10 dB Pushbutton
Check the Operation of the Video Filters 3-3
Check Sensitivity
Check Spurious Signals from Internal Sources
(Residual Responses) 3-5
Check Resolution Bandwidth and Shape Factor
Check Incidental Wing 3-6
Check Sweep Circuit Operation with the TIME/DIV in the
MANUAL, and OFF Positions 3-7
Performance Checks Requiring Test Equipment
Equipment Required
Check the Calibrator Frequency 3-9
Check Calibrator Output Level
Check RF Attenuator Accuracy 3-10
Check Display Flatness
Check Intermodulation Distortion 3-11
Check Pulse Stretcher Operation 3-12
Check Triggering Operation and Sensitivity 3-13
Check The External Horizontal Input Voltage Requirement 3-14
Check the Video Output Level 3-15
Check Frequency Span Accuracy and Linearity
Check Time/Div Accuracy 3-16
TABLE OF CONTENTS (cont)
SECTION 4 CALIBRATION Page
Equipment Required 4-1
Short Form Procedure and Record
Time Base Section
Adjust Sweep Length, Offset, and Triggering 4-3
Function IF Alignment 4-6
Adjust the LIN Mode Baseline Offset
Adjust the Gain Compensation and Calibrate the
Reference Level
1st LO Phase Lock Loop
Error Amplifier Offset Adjustment 4-8
Frequency Span and 1st LO Calibration
Adjust the Frequency Span of the 1st LO and the
16-19 MHz Oscillators
Calibrate the Center Frequency and Frequency Readout 4-10
Phase Lock Calibration Adjustments
Adjust Memory Gain 4-11
Adjust Error Amplifier Gain
Resolution
Adjust the Bandpass of the 105 MHz IF Amplifier
and 300 kHz Filter 4-12
Adjust the Resolution Gain Leveling Compensation 4-14
Adjust the Post Resolution Amplifier Gain 4-16
Minimize Intermodulation Products
50 MHz Calibrator
Adjust the Calibrator Output
SECTION 5 CIRCUIT DESCRIPTION
Block Diagram Description 5-1
Detailed Circuit Description 5-2
RF or Microwave Circuits
Phase Lock and Frequency Stablization 5-3
YIG Driver, Voltage Memory and Phase Lock Logic 5-4
Frequency Tuning Control and Readout 5-5
Tuning Control
YIG Driver
Frequency Span 5-6
Marker Generator
105 MHz IF Amplifier, 3rd Mixer and Oscillator
10 MHz IF Pre-resolution Amplifier and
Resolution Filter Circuits
YIG Oscillator Power Supply 5-7
30 Hz Filter
50 MHz Calibrator
Function IF Amplifier
Video Filter, Pulse stretcher, Baseline Clipper
& Vertical Output 5-8
Frequency Readout 5-9
Uncal Circuit 5-11
Sweep Triggering Sweep Generator and
Horizontal Amplifiers 5-12
TABLE OF CONTENTS (cont)
SECTION 6 MAINTENANCE INSTRUCTIONS Page
Preventive Maintenance 6-1
Cleaning
Lubrication
Visual Inspection
Transistor and Integrated Circuit Checks
Performance Checks and Recalibration
Troubleshooting 6-2
Troubleshooting Aids
Diagrams
Circuit Board Illustrations
Wiring Color Code
Multiple Terminal (Harmonic) Connector Holders
Resistor Code
Capacitor Marking
Diode Color Code
Transistor and Integrated Circuit Electrode Configuration
Diode Checks 6-3
IC Checks
General Troubleshooting Techinque
Corrective Maintenance 6-5
Obtaining Replacement Parts
Repair and Exchange Program
Soldering Technique
Replacing Square Pins for Multi-pin Connectors 6-6
Replacing Assemblies
Front Panel Controls and Selectors
Circuit Board Assemblies 6-8
DVM Logic and Readout Circuit Board
Replacing the Sweep Circuit Board
Replacing the IF Function Circuit Board 6-10
Replacing the Resolution Circuit Board
Replacing Circuit Boards in the Honeycomb Assembly
Replacing Microwave Assemblies
Replacing the 2.095 GHz Filter Assembly A10,
or the Multiplier-Bandpass Filter A401 6-11
Replacing the Multipler 2.18 GHz Bandpass
Filter and 16-19 MHz Mixer Circuit Board Assembly 6-13
SECTION 7 OPTIONS AND MODIFICATIONS
SECTION 8 ELECTRICAL PARTS LIST
SECTION 9 DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS
SECTION 10 MECHANICAL PARTS LIST
CHANGE INFORMATION
Fig. 1-1 . 71-13 Spectrum Analyzer.
Section 1-71-13
GENERAL INFORMATION
AND
SPECIFICATIONS
INTRODUCTION assembly and component locations . IC logic diagrams,
waveforms and voltage data, for troubleshooting orcircuit
Abbreviations used in the text and diagrams are based analysis, are also provided adjacent to or on the diagram .
on ANSI Y 1 .1, 1972 Standards . This manual is divided into
ten major sections that provide the following information :
Section 10 - Mechanical Parts List, Exploded
Section 1 - General Information and Specifications : Drawings and Accessories : Provides information
Contains the instrument description and specifications . necessary to order replaceable parts. The Parts List is
cross-referenced to the Electrical Parts List. Exploded
drawing shows sequence of assembly and identifies
Section 2 - Operation Instructions : Information assemblies.
relative to installing and operating the instrument.
Changes and Corrections : Provides updating informa-
Section 3 - Performance Check: Provides procedures tion for the manual in the form of inserts. These inserts are
to check the operational performance of the instrument incorporated into the manual text and diagrams when the
plus additional performance check procedures that re- manual is reprinted .
quire test equipment to verify that instrument perfor-
mance is in accordance to specifications .
DESCRIPTION
Section 4 - Calibration Procedure : Describes test The 71-13 Spectrum Analyzer is a high-performance
equipment setup and adjustment procedures required to communication spectrum analyzer that plugs into and
calibrate the instrument. operates with the 7000-Series mainframe oscilloscopes . It
is a swept front end analyzer that displays absolute
amplitude information of signals within the frequency
Section 5 - Circuit Description : Provides basic and span of 0 Hz to 1 .8 GHz. Time domain characteristics,
general circuit analysis that may be useful when servicing within a 3 MHz bandpass, can also be displayed .
or operating the instrument.
Important features of the 71-13 are : 1) Greater than
Section 6 - Maintenance Instructions : Describes 70 dB dynamic range. 2) Sensitivity down to -128 dBm .
routine and corrective maintenance procedures with 3) Resolution capability from 3 MHz to 30 Hz.
detailed instructions for replacing assemblies, sub- 4) Incidental Wing less than 10 Hz. 5) Fully calibrated
assemblies, and individual components. Troubleshooting display modes of either 10 dB/Div, 2 dB/Div, or Linear ;
procedures, plus general information that may aid in and a calibrated reference level in dBm . 6) Calibrated
servicing the instrument, are also provided . An exploded sweep spans from 100 MHz/Div to 200 Hz/Div . 7) Digital
drawing is part of Section 10. frequency readout . 8) Full range of video filtering for noise
averaging . 9) Baseline clipping to subdue the bright
baseline of displays when photographing . 10) Pulse
Section 7 - Options : Describes options available for stretching, to enhance pulsed spectra when using wide
the instrument. frequency spans and resolution bandwidths . 11) Access
for a tracking generator . 12) Frequency and amplitude
reference calibrator.
Section 8 - Electrical Parts List: Provides information
necessary to order replaceable parts and assemblies.
If the 7000-Series mainframe features crt readout, the
signal parameters and other pertinent information, such
Section 9 - Diagrams: Provides functional block as resolution bandwidth, video filtering, and frequency
diagram and detailed circuit schematics. Located adja- span, are displayed on the crt readout to simplify the
cent to the diagram (usually on the back of the preceding operation of the instrument. Records can then be made of
diagram) are pictoral layout drawings that show sub- pertinent data by photographing the display .
Specification-7L13
The analyzer requires three plug-in widths in the 7000- STABILITY (after a 2 hour warmup period)
Series mainframe.
Within 2 kHz per hour at a fixed temperature, when '^
phase locked ; within 50 kHz when not phase locked .
ELECTRICAL CHARACTERISTICS
INCIDENTAL FM (see Fig. 3-5)
The following characteristics and features of the 7L13 10 Hz (peak-to-peak) or less when phase locked, and
Spectrum Analyzer are applicable after a warmup period 10 kHz (peak-to-peak) or less for 5 seconds when out of
of 30 minutes or more . phase locked mode .
CENTER FREQUENCY
VIDEO FILTERING
Range: 1 kHz to 1 .8 GHz.
Three selections of video filtering; 10 Hz, 300 Hz and
30 kHz are provided for signal or noise averaging .
Resolution of the Center Frequency Indicator: Within
1 MHz.
DISPLAY
Accuracy : f(5 MHz + 20% of the Freq Span/Div) . LOG 10 dB/DIV : Provides a calibrated 70 dB dynamic
range with an accuracy that is within 0.1 dB/1 dB to a
maximum of 1 .5 dB over the full dynamic range.
The center frequency is indicated by LED readout on
the 7L13 and crt readout when the 7000-Series mainframe
has this feature. LOG 2 dB/DIV : Provides a calibrated 14 dB dynamic
range with an accuracy that is within t0 .4 dB/2 dB to a
maximum of 1 .0 dB over the 14 dB dynamic range.
FREQUENCY SPAN
Calibrated spans from 200 Hz/Div to 100 MHz/Div in a LIN: Provides a linear display from approximately
1-2-5 sequence, plus O Hz and MAX SPAN positions. In the 0 .7 /jV (100 dBm) full scale, to 7 .07 volts (+30 dBm) .
0 Hz position, the analyzer is a fixed tuned receiver for Amplitude linearity is within 10% over the graticule height .
time domain analysis . In the MAX SPAN position the
frequency span is approximately 1 .8 GHz.
REFERENCE LEVEL
Accuracy : Within 5%of the indicated frequency separa-
tion . Linearity over the center 8 divisions is within 5% . Reference level operation is in calibrated 10 dB steps
from -110 dBm to +30 dBm, within t2 dB . (Accuracy
includes the attenuator and gain switching effects when
the two are not offsetting each other.) Reference level
RESOLUTION
operation below 100 kHz becomes limited to a rangefrom
Six resolution bandwidth selections from 30 Hz to +30 dBm to-50 dBm as the center frequency approaches
3 MHz, in decade steps, are provided . Resolution 1 kHz.
bandwidth may be coupled or uncoupled from the fre-
quency span selector .
Reference level deviation, between display modes, is
less than 2 dB from 2 dB/DIV to 10 dB/DIV and less than
Bandwidth accuracy : Resolution bandwidth, at the 0.5 divisions from 2 dB/DIV to LIN. This deviation is a
6 dB down point, is within 20% of the resolution selected . function of the oscilloscope vertical linearity.
Shape factor (60:6 dB ratio) : 12 :1 or better for 30 Hz An LINCAL indicator signifies when the display is not
resolution and 4:1 or better with resolution of 300 Hz or calibrated .
more except 3 MHz. Maximum bandwidth 60 dB down
with 3 MHz resolution, is 13 MHz.
DISPLAY FLATNESS
Signal level change over the six resolution bandwidth +1 dB, -2 dB with respect to the level at 50 MHz, over
selections is less than 0.5 dB . any selected frequency span .
Specification-7L13
CALIBRATOR positions provide an additional 40 dB of gain only in the
2 dB/DIV and LIN modes. The 10 dB pushbutton provides
50 MHz