Tektronix 7L13 User manual

070-1673-00
TEKTRONIX
7L13
SPECTRUM
ANALYZER
INSTRUCTION
MANUAL
Tektronix, Inc .
P .O . Box 500
Beaverton, Oregon 97005

Serial Number
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
SECTION 5
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
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)
CHANGE INFORMATION
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

Fig . 1-1 . 71-13 Spectrum Analyzer .

INTRODUCTION
GENERAL INFORMATION
AND
SPECIFICATIONS
Abbreviations used in the text and
diagrams are based
on
ANSI Y 1 .1, 1972 Standards . This manual is divided into
ten major sections that provide the following information :
Section
1 - General Information and Specifications :
Contains the instrument description and specifications .
Section 2 - Operation Instructions : Information
relative to installing and operating the instrument .
Section 3 - Performance Check : Provides procedures
to check the operational performance of the instrument
plus additional performance check procedures that re-
quire test equipment to verify that instrument perfor-
mance is in accordance to specifications .
Section 4 - Calibration Procedure : Describes test
equipment setup and adjustment procedures required to
calibrate the instrument .
Section 5 - Circuit Description : Provides basic and
general circuit analysis
that
may be useful
when servicing
or operating the instrument .
Section 6 - Maintenance Instructions : Describes
routine
and
corrective maintenance procedures with
detailed instructions for replacing assemblies, sub-
assemblies, and individual components . Troubleshooting
procedures, plus general information that may aid in
servicing the instrument, are also provided . An exploded
drawing is part of Section 10 .
Section 7 - Options : Describes options available for
the instrument .
Section 8 - Electrical Parts List : Provides
information
necessary to order replaceable parts and assemblies .
Section 9 - Diagrams : Provides functional block
diagram and detailed circuit schematics . Located adja-
cent to the diagram (usually on the back of the preceding
diagram) are pictoral layout drawings that show sub-
Section 1-71-13
assembly and component locations . IC logic diagrams,
waveforms and voltage data, for troubleshooting orcircuit
analysis, are also provided adjacent to or on the diagram
.
Section 10 - Mechanical Parts List, Exploded
Drawings and Accessories : Provides information
necessary to order replaceable parts . The Parts List is
cross-referenced to the Electrical Parts List . Exploded
drawing shows sequence of assembly and identifies
assemblies .
Changes and Corrections : Provides updating informa-
tion
for
the manual
in
the
form
of inserts
. These inserts are
incorporated
into the
manual
text and diagrams when the
manual is reprinted .
DESCRIPTION
The 71-13 Spectrum Analyzer is a high-performance
communication
spectrum
analyzer that plugs into and
operates with the 7000-Series mainframe oscilloscopes . It
is a swept front end analyzer that displays absolute
amplitude
information
of
signals within the frequency
span of 0 Hz to 1 .8 GHz . Time domain characteristics,
within a 3 MHz bandpass, can also be displayed .
Important features of
the 71-13
are :
1) Greater than
70 dB dynamic range . 2) Sensitivity down to
-128 dBm .
3) Resolution capability from 3 MHz to 30 Hz .
4) Incidental Wing less than 10 Hz . 5) Fully calibrated
display modes of either 10 dB/Div, 2 dB/Div, or Linear ;
and a calibrated reference level in dBm . 6) Calibrated
sweep spans from 100 MHz/Div to 200 Hz/Div . 7) Digital
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
stretching, to enhance pulsed spectra when
using
wide
frequency spans and resolution bandwidths .
11)
Access
for a tracking generator . 12) Frequency and amplitude
reference calibrator .
If the 7000-Series mainframe features crt readout, the
signal
parameters and
other pertinent information, such
as resolution bandwidth, video filtering, and frequency
span, are displayed on the crt readout to simplify the
operation of the instrument . Records can then be made of
pertinent data by
photographing the display .

Specification-7L13
The analyzer requires three plug-in widths in the 7000-
Series mainframe .
The following characteristics
and
features of
the 7L13
Spectrum
Analyzer are applicable after a warmup period
of 30 minutes or more .
CENTER
FREQUENCY
Resolution of the Center Frequency Indicator : Within
1 MHz .
The center frequency is indicated by LED readout on
the 7L13 and crt readout when the 7000-Series mainframe
has this feature .
FREQUENCY SPAN
Calibrated spans from 200 Hz/Div to 100 MHz/Div in a
1-2-5 sequence, plus O Hz and MAX SPAN positions . In the
0 Hz position, the analyzer is a fixed tuned receiver for
time domain analysis . In the MAX SPAN position the
frequency span
is approximately 1
.8 GHz .
Accuracy : Within 5%of the indicated frequency separa-
tion . Linearity over the center 8 divisions is within
5%
.
RESOLUTION
Six resolution bandwidth selections from 30 Hz to
3 MHz, in decade steps, are provided . Resolution
bandwidth may
be coupled or uncoupled from the fre-
quency span selector .
Bandwidth accuracy : Resolution bandwidth, at the
6 dB down point, is within
20% of
the
resolution selected .
Shape factor (60 :6 dB ratio) : 12 :1 or better for 30 Hz
resolution and 4 :1 or better with resolution of 300 Hz or
more except 3 MHz . Maximum bandwidth 60 dB down
with 3 MHz resolution, is 13 MHz .
Signal level change over the
six resolution bandwidth
selections is less than 0 .5 dB .
ELECTRICAL
CHARACTERISTICS
Range : 1 kHz to 1 .8 GHz .
Accuracy : f(5 MHz + 20% of the Freq Span/Div) .
STABILITY (after a 2 hour warmup period)
Within 2 kHz per hour at a fixed temperature, when '^
phase locked ; within 50 kHz when not phase locked .
INCIDENTAL FM (see Fig .
3-5)
10 Hz (peak-to-peak) or less when phase locked, and
10
kHz
(peak-to-peak) or less
for
5 seconds when out of
phase locked mode .
VIDEO FILTERING
Three selections of video filtering ; 10 Hz, 300 Hz
and
30 kHz are provided for signal or noise averaging .
DISPLAY
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 .
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 .
LIN : Provides a linear display from approximately
0 .7 /jV (100 dBm) full scale, to 7 .07 volts
(+30
dBm) .
Amplitude linearity is within 10% over the graticule height .
REFERENCE LEVEL
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
operation below 100 kHz becomes limited to a rangefrom
+30 dBm to-50 dBm as the center frequency approaches
1 kHz .
Reference level deviation,
between display modes, is
less than 2 dB from 2 dB/DIV to 10 dB/DIV and less than
0 .5 divisions from 2 dB/DIV to LIN . This deviation is a
function
of the oscilloscope vertical linearity .
An LINCAL indicator signifies when
the display is not
calibrated .
DISPLAY FLATNESS
+1 dB, -2 dB with respect
to
the level at 50 MHz, over
any selected frequency span .

CALIBRATOR
50 MHz ±0 .01% with an absolute amplitude level of
-30 dBm ±0 .3 dB, at 25°C . 50 MHz harmonics are
generated to provide a comb of
markers for
frequency
span calibration .
CW
SENSITIVITY (Signal
+
noise
=
2x noise, In LIN
display mode)
The following characteristics are applicable from
100 kHz to 1 .8 GHz : Below 100 kHz the sensitivity
degrades approximately 0 .3 dB/kHz ; for example, the
sensitivity at 50 kHz with 30 Hz resolution is, -113 dBm or
better ; at 1 kHz, -98 dBm or better .
SPURIOUS SIGNALS FROM INTERNAL SOURCES
(Residual
Response)
Equal
to or less than -100 dBm, referred to the 1st
mixer input .
INTERMODULATION DISTORTION (Fig . 3-6)
100
kHz -
1 .8 GHz : Third order intermodulation
products
are
down 70 dB or more from two -30 dBm
signals within any frequency span, second order products
are down 70 dB or more from two -40 dBm signals within
any frequency span .
100 kHz - 1 kHz : Intermodulation products (3rd and
2nd) are down 50 dB or more for the same input level as
above .
GAIN
The gain range is 80 dB total . An eight position selector
changes the IF gain 70 dB in 10 dB (±1 .0 dB) steps and a
10
dB pushbutton
adds an
additional
10
dB
of
gain when
the REFERENCE LEVEL is -100 dBm and 30 Hz resolu-
tion bandwidth is used, in the 2 dB/DIV or LIN mode .
Four positions (blue sector) of the selector provide
30 dB of change in all display modes . The remaining four
RFATTENUATOR
NOTE
SWEEP MODES AND RATE
TRIGGERING
Specification-7L13
positions provide an additional 40 dB of gain only in the
2
dB/DIV and LIN modes . The 10 dB pushbutton provides
the
additional 10 dB of gain, when the resolution bandwith
is 30 Hz and the REFERENCE LEVEL
is -100
dBm in
the
2 dB/DIV or LIN mode .
The REF VARiable control provides
continuous
gain
adjustment between each calibrated REFERENCE LEVEL
setting .
Provides 60 dB of attenuation in
calibrated 10 dB steps .
Accuracy is ±0 .2 dB or 1 % of the dB reading, whichever is
greater
.
The maximum input power level
to
the
RFA ttenuator
is 1 watt average and 200 watts peak . +13 dBm will
destroy the 1st mixer .
Selection of an external sweep source, manual sweep,
or calibrated sweep rates from 10 s/Div to 1 ps/Div in a 1-
2-5 sequence are provided . Sweep rate accuracy is within
5% of that selected .
Three triggering sources can
be selected .
INTernal
selects the vertical or video component from either vertical
plug-in
compartment, EXTernal selects the signal applied
to the EXT IN HORIZ/TRIG connector and LINE selects a
sample of the mainframe line voltage
.
INTernal signal
is ac
coupled with an approximate frequency range from 15 Hz
to 1 MHz . The external and line signals are do coupled .
Input
impedance for the external input is about 30 kid for
the trigger
mode and 9 kQ for external horizontal sweep
mode .
Trigger sensitivities are : 1)
<0
.5 division of internal
signal (peak-to-peak) and <0 .5 volt of signal (peak-to-
peak) of external signal for NORM mode . 2) <0 .5 division
of
internal signal
peak-to-peak and <0 .5 volt of external
signal for SGL SWP mode .
RESOLUTION BANDWIDTH SIGNAL LEVEL
30 Hz -128 dBm
300 Hz -120 dBm
MAXIMUM INPUT POWER LEVEL
3 kHz -110 dBm
30 kHz -100 dBm
-30
dBm with the
RF Attenuator at 0 dB, for linear
.3 MHz -90 dBm
operation, +30 dBm with the RF
Attenuator at 60 dB .
3 MHz -80 dBm
(+30 dBm is
also
the
power
rating of
the RF Attenuator .)

Specification-71-13
In the NORM mode
the sweep will automatically recur
at
the end of holdoff time if a trigger signal
is absent, to
provide a baseline on
the crt .
The SGL SWP and "start"
buttons function together to
provide a single sweep
each time the "start" button is
pushed .
VIDEO
OUTPUT CONNECTOR
Provides 50 mV t5%
of video signal per display
division, about the
crt vertical center . Source impedance is
approximately
1 kit . A maximum of 50 mV offset
may be
introduced by
the error from the
mainframe vertical
centering interface .
EXTERNAL
HORIZONTAL/TRIGGER INPUT
CONNECTOR
Requires 0 V to 10 V t1
V, to sweep the full frequency
span .
Requires 0 .5 volt peak-to-peak
to trigger the sweep
circuits .
Maximum safe input ; 50 volts (dc + peak ac) .
ENVIRONMENTAL CHARACTERISTICS
This instrument
will meet the electrical characteristics
over
the environmental limits of the 7000-Series
main-
frame . Complete details on test procedures,
including
failure criteria, etc ., can be obtained
from Tektronix, Inc .
Contract your local
Tektronix Field Office or represen-
tative .
ACCESSORIES AND OPTIONS
STANDARD ACCESSORIES
1 . Spectrum Analyzer
Graticule : Clear plastic implo-
sion shield
with
LOG,
LIN, REF and f (frequency)
direction
markings . Tektronix Part No .
337-1439-01 for 7403N
oscilloscope and 337-1159-02
for other 7000-Series os-
cilloscopes .
attenuator with DC block
OPTIONS TO 7000-SERIES
OSCILLOSCOPES
1 . CRT with P7 phosphor and time
domain graticule .
The external graticule
for spectrum analysis (part of
standard accessories) should be
used .
2 . CRT with P7 phosphor and an
internal spectrum
analyzer graticule (designated
P7SA) . This is
recommended when the oscilloscope
mainframe is to be
used exclusively with spectrum
analyzer systems .
2 . Filter
Light Amber 378-0684-01
3 .
50 i2 Coaxial Cable,
012-0113-00
with BNC connectors,
6 foot
4 . BNC Male to
N Female Adapter 103-0058-00
5 . Manual
070-1673-00
OPTIONAL ACCESSORIES
1 . DC Block (for
applying 015-0221-00
signals
riding on a DC poten-
tial) . Maximum potential is
50VDC
2 . 75 0 to 50 i2 minimum loss
011-0112-00