Tektronix SG 505 User manual

Tektronix , Inc.
P.O.
Box 500
Beaverton ,
Oregon
070-4359-00
Product
Group 75
97077
Tektronix
COMMITTED TO
EXCELLENCE
PLEASE CHECK FOR CHANGE INFORMATION
AT THE REAR OF THIS MANUAL .
SG
505
OPTION
02
OSCILLATOR
INSTRUCTION
MANUAL
Serial Number
First
Printing NOV
1982

Copyright
1979 ,
1982
Tektronix ,
Inc.
All rights
reserved .
Contents of this publication may not be reproduced in any
form
without the
written permission
of
Tektronix , Inc.
Products of
Tektronix ,
Inc.
and its
subsidiaries
are covered
by
U.S.
and foreign
patents
and
/ or
pending
patents .
are regis
TEKTRONIX ,
TEK
,
SCOPE -
MOBILE
,
and
tered
trademarks of
Tektronix
, Inc.
TELEQUIPMENT
is a
registered
trademark of
Tektronix
U.K.
Limited .
Printed in
U.S.A. Specification
and price
change privileges
are
reserved .
O

O
PREFACE
The information in this instruction manual describes only the
Option 02 version of the SG 505 Oscillator . All references in
this manual to the SG 505 Oscillator refer only to the Option
02
version , unless
otherwise
indicated .
SG
505
Opt .
02
A
separate
instruction
manual is
available
for the
standard
SG
505
Oscillator , with Option
01
information .
Contact
your
local
Tektronix field office
or representative
for order
ing
information .
i

O
Preface
List of Illustrations
List of Tables
Operators Safety Summary
Servicing Safety Summary
Section 1 SPECIFICATION
TABLE OF CONTENTS
Introduction ....
Standard
Accessories ...
Performance Conditions
Electrical Characteristics ..
Front Panel ....
Rear Interface
Miscellaneous
Environmental ..
Physical
Characteristics
Section 2 OPERATING INSTRUCTIONS
Preparation
for Use
..
Repackaging
Information
Controls and Connectors
Operators
Familiarization .
General Operating Information
Frequency
Selection
.
Output Level Selection ..
Intermodulation
Test
Signal
Output
Connections
...
Rear
Interface
Signals
WARNING
Page
i
iv
V
vi
Section 3 THEORY OF OPERATION
Introduction ....
Phase Shift Oscillator
Amplitude
Detector
Peak
Detector ...
Amplitude
Control
vii
1-1
1-1
1-1
1-2
1-2
1-3
1-4
1-5
1-5
THE
FOLLOWING SERVICING INSTRUC
TIONS ARE FOR USE BY QUALIFIED PER
SONNEL ONLY . TO AVOID PERSONAL INJU
RY , DO NOT PERFORM ANY SERVICING
OTHER THAN THAT CONTAINED IN OPER
ATING
INSTRUCTIONS UNLESS
YOU ARE
QUALIFIED TO DO SO .
2-1
2-1
2-2
2-4
2-4
2-4
2-4
2-4
2-4
2-7
3-1
3-1
3-1
3-1
3-1
Section
3
THEORY OF
OPERATION
(
cont
)
Output Buffer Amplifier ...
Sync Driver and Sync Amplifier
Power
Supply
IMD Oscillator
Inverting Buffer and Power Amplifiers
Output Attenuators and Rear Interface
Buffers ....
Section 4 CALIBRATION PROCEDURE
Introduction
..
Test Equipment Requirements
Performance Check ....
Introduction ...
Test
Equipment
Required .
Preparation
Procedure .
Adjustments
Introduction
...
Test Equipment Required .
Preparation
Procedure .
SG
505
Opt .
02
Section 5 MAINTENANCE
Introduction
..
Obtaining Replacement Parts
Cleaning
Instructions
.....
Circuit Board Removal and Installation
Low
Frequency
Selection .
Troubleshooting
Aids
Troubleshooting Equipment
Static
-
Sensitive
Components
Section
6
OPTIONS
Accessories
Section 7 REPLACEABLE ELECTRICAL PARTS
Section 8 DIAGRAMS AND CIRCUIT BOARD
ILLUSTRATIONS
Change
Information
.
Section 9 REPLACEABLE MECHANICAL PARTS
AND EXPLODED VIEW
Page
3-1
3-2
3-2
3-2
3-2
3-3
4-1
4-1
4-3
4-3
4-3
4-3
4-3
4-15
4-15
4-15
4-15
4-15
5-1
5-1
5-1
5-1
5-2
5-3
5-3
5-3
iii

SG
505
Opt
.
02
Fig
.
No.
2-1
2-2
2-3
2-4
2-5
2-6
2-7
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
5-1
8-1
8-2
8-3
8-4
iv
LIST OF ILLUSTRATIONS
SG 505 Option 02 installation and removal
SG 505 Option 02 front panel controls and connectors
Connection
configurations
Floating oscillator grounded to unit under test to break up ground loops
Added capacitor between CT and chassis ground improves RFI rejection
SG 505 CT terminal grounded and cable shield connected to ground post
Three conductor shielded cable allows CT to be remotely grounded while cable shield is grounded at both
ends ....
Attenuator step
accuracy setup
Distortion
measurement
setup
10
Hz
null
adjustment
10 Hz
harmonic distortion
display
20
Hz
harmonic
distortion
display
20 kHz
harmonic distortion
display
FREQUENCY Hz dial
adjustment
Location of
R1423
,
Amp Cal
Adj
Location
of
R1126 , Bal Adj
Location
of
R1301 , Sync Lvl
Adj
Location of R1339 , Im Ratio Adj
Intermodulation signal LF switch
NOTE
The following illustrations are located in the diagrams foldout section at
the
rear of this
manual
.
Troubleshooting flow
chart oscillator and output circuits
Main
Board
(
A12
)
Troubleshooting flow chart- power supply
Option 02 board ( A13 )
Page
2-1
2-3
2-5
2-6
2-6
2-7
2-7
4-5
4-9
4-9
4-10
4-11
4-12
4-15
4-16
4-17
4-17
4-18
5-3

10
Table
No.
1-1
1-2
1-3
1-4
4-1
4-2
4-3
4-4
4-5
4-6
4-7
5-1
8-1
8-2
8-3
8-4
8-5
8-6
Electrical characteristics
Miscellaneous
Environmental
LIST OF
TABLES
Physical characteristics ...
List
of
test
equipment
requirements
Frequency accuracy check
Attenuator
step
accuracy
Level
flatness check
Level
flatness
check (
alternative
method )
Harmonic
correction
factors
Factors
for
THD
computation
Relative
susceptibility to
static discharge
damage
NOTE
The following tables are located in the diagrams foldout section at the
rear
of this
manual
.
Component
reference
chart
Rear
interface
connector
assignments
Component
reference
chart
Component
reference
chart
Component
reference
chart
Component
reference
chart
SG
505
Opt .
02
Page
1-2
1-4
1-5
1-5
4-1
4-3
4-5
4-7
4-8
4-10
4-11
5-4
V

SG
505 Opt . 02
The
general safety
information
in this
part of the
summary
is
for both operating and servicing personnel . Specific
warnings and
cautions will be
found throughout the
manual
where they apply , but may not appear in this summary .
In This Manual
CAUTION statements identify conditions or practices that
could result in damage to the equipment or other property .
OPERATORS
SAFETY
SUMMARY
WARNING statements identify conditions or practices that
could
result in
personal injury
or loss of life .
TERMS
As
Marked on
Equipment
CAUTION indicates a personal injury hazard not immediate
ly accessible as one reads the marking , or a hazard to prop
erty
including
the
equipment
itself .
In
This Manual
DANGER indicates a personal injury hazard immediately ac
cessible as one reads the marking .
vi
!
SYMBOLS
As
Marked
on
Equipment
4
This symbol indicates where applicable
cautionary
or
other information
is to be
found
.
DANGER
High voltage .
Protective ground ( earth ) terminal .
ATTENTION refer to manual
.
-
Refer to manual
Power
Source
This product is intended to operate in a power module con
nected to
a power
source
that will
not
apply
more
than
250
volts
rms
between the
supply
conductors
or between
either
supply conductor and ground . A protective ground connec
tion
by way
of the
grounding
conductor
in the
power cord
is
essential for safe operation .
Grounding
the
Product
This
product
is grounded
through the
grounding
conductor
of
the
power
module
power
cord . To
avoid
electrical
shock ,
plug the
power
cord
into
a
properly
wired
receptacle
before
connecting to
the
product input or
output
terminals . A pro
tective
ground connection by
way of the
grounding
conduc
tor in the power cord is essential for safe operation .
Danger
Arising
From
Loss
of
Ground
Upon loss
of the
protective
- ground
connection
, all
accessi
ble
conductive
parts ( including
knobs and
controls that may
appear
to be
insulating
)
can render
an
electric
shock
.
Use The Proper Fuse
To avoid fire hazard , use only the fuse specified in the parts
list
for your product
, and which
is
identical
in type
, voltage
rating and current rating .
Refer
fuse
replacement to
qualified service
personnel .
Do Not Operate in Explosive Atmospheres
To
avoid
explosion , do not operate
this product in
an explo
sive
atmosphere
unless it has
been
specifically
certified for
such
operation .
Do
Not
Operate Plug - In
Unit Without
Covers
To
avoid
personal
injury , do not
operate
this
product with
out
covers or panels
installed . Do
not apply power
to the
plug - in
via a
plug
- in
extender
.

SERVICING
SAFETY
SUMMARY
FOR
QUALIFIED
SERVICE
PERSONNEL
ONLY
Refer
also to
the
preceding
Operators
Safety
Summary
Do Not
Service
Alone
Do not
perform
internal
service or
adjustment
of
this
prod
uct
unless
another
person
capable
of
rendering first aid
and
resuscitation
is
present
.
Use
Care When
Servicing
With Power On
Dangerous
voltages
exist
at
several points in this
product
.
To avoid
personal
injury
, do not
touch
exposed
connections
and
components
while
power is
on .
Disconnect
power
before
removing
protective
panels
,
sol
dering
,
or
replacing
components .
SG
505
Opt .
02
Power
Source
This
product
is
intended to
operate in a
power
module con
nected
to
a
power
source that will not
apply
more
than
250
volts rms
between
the
supply conductors or
between either
supply
conductor and
ground
. A
protective
ground
connec
tion by way
of the
grounding
conductor in the power
cord is
essential
for safe
operation
.
Do
Not
Wear
Jewelry
Remove
jewelry
before
servicing
this
instrument
.
Rings
,
necklaces , and
other metallic
objects
could
come into con
tact with
dangerous
voltages
and
currents
.
vii

SG 505 Opt . 02
viii
SOURCE
R
INTERMOD
TEST
SIG
LF
+
FREQ
MIXED
4 : 1
ON
SYNC
OUT
SG
505
OSCILLATOR
VERNIER
9'L
50
01
8
150
-28
-18
Tektronix
OUTPUT
LEVELA
dBm
INTO
800
(
2
+2
-8
+12
-30
FREQUENCY
Hz
CT
-48
BALANCED
OUTPUT
SG
505
Option 02
Oscillator
.
CAL
25
+22
2
+
28
Rs
=
5052
NCAL
X10k
Xik
X100
X10
-25Vpk
ON
GND
FLTG
POWER
4359-01

Introduction
10 25 25 .
The
TEKTRONIX SG 505
Option 02
Oscillator
generates
an
ultra low distortion sine wave over the freqency range from
10 Hz to 100 kHz . This balanced output can be floated or
referenced to chassis ground . The oscillator also provides a
fixed amplitude ground referenced sine wave signal at the
SYNC OUT connector that is identical in frequency to the
signal from the OUTPUT connector . Versions of both output
signals are
available at the
rear
interface connector
. The
output
source
impedance is
selectable
.
Standard Accessories
1 Instruction Manual
1 Cable
SPECIFICATION
The Option 02 SG 505 also provides an intermodulation test
signal function . This signal consists of a low frequency sine
wave mixed with the selected frequency in a 4 : 1 amplitude
ratio . The lower frequency sine wave is internally selectable
for 60 Hz or 250 Hz . The SG 505 is designed to operate in
one
compartment of any
TM
500
or
TM
5000
Series
Power
Module .
z
jed
Refer to the Accessories page at the back of this manual for
part
numbers
.
Section 1 - SG
505 Opt .
02
Performance Conditions
The limits stated in the Performance Requirements column
of the specification tables are valid with the following
conditions :
1. The instrument's internal adjustments are performed at
an ambient temperature between + 20 ° and + 30 ° C .
2. The instrument must be in a non - condensing environ
ment whose limits are described under Environmental .
3. Allow twenty minutes warm - up time for operation to
specified
accuracy
; sixty
minutes after
exposure
to or stor
age
in
high -
humidity (
condensing )
environment .
Items listed in the Performance Requirements column of the
Electrical Characteristics are verified by completing the Per
formance Check in the Checks and Adjustments section of
this manual . Information given in the Supplemental Informa
tion and Description columns of the following tables is pro
vided for user information only and should not be interpreted
to be Performance Check requirements .
1-1

Specification - SG 505 Opt . 02
Characteristics
FREQUENCY
Range
Vernier
Range
Dial
Accuracy
Drift
OUTPUT LEVEL
Calibrated
Output
( f =
1
kHz )
Rs 600 in
CAL
detent
Rs 50
just
ccw
of
=
CAL
detent
Attenuator
Step
Accuracy
( f = 1 kHz
)
Stability
Variable
Range
Settling
Time
LEVEL FLATNESS
( 1 kHz ref ,
R₁
1-2
OUTPUT
10 Hz - 20
kHz
20 kHz
100 kHz
-
Impedance
=
600
22
)
Table 1-1
ELECTRICAL CHARACTERISTICS
Performance
Requirements
FRONT PANEL
10 Hz to 100 kHz in four overlapping bands . Typically 9 Hz to 110 kHz . Nominal range of
each band is 0.90 to 11.0 .
> ± 1 % of frequency setting .
±
3 % of setting
with
vernier at center .
+22
dBm ( 9.75
V rms ) ± 0.2 dB
into 600
At least 11 dB .
±
0.1 dB
±
0.2
dB
± 0.1 dB for
any 10 or 20 dB
step
change .
Supplemental
Information
Balanced and selectable : 600 ± 2 % ,
150 ± 2 % , 50 ± 3 %
Typically less
than 0.01 % /
° C and 0.03 %
/ hour .
Maximum output
> 21 V rms
unloaded .
Maximum output with variable out of CAL
position
increases
to
+22.7
dBm .
+28
dBm ( 19.46
V rms ) ±
0.3 dB into 600
and at least +30 dBm ( 12.25 V rms ) into 150 N.
Range
is
+22
dBm
to
-68
dBm
.
Typically
better than
0.01 dB
/ ° C and
0.03
dB
/
hour
.
Nominal
range is +0.7
dB to <
-10 dB .
< 5 seconds to 0.2 dB of final value ,
20 Hz - 100 kHz ; typically < 3 seconds above
100 Hz . Worst case transient overshoot is < 3
dB .
Flatness is above 50 kHz unspecified on
-58
dBm
and
-68
dBm
ranges .
Floating or grounded through approximately
30 22. Output impedance does not change with
OUTPUT ON / OFF selection . Capacitance
between output common and chassis ground in
floating mode to 330 pF .
Impedance
to CT is one
- half the
selected
impedance
.

O
Characteristics
OUTPUT
(
cont
)
Balance
( f < 20
kHz ,
Output
GNDed
)
Typical
Dc
Offset
Maximum
Floating
Voltage
DISTORTION (
Maximum
Specified
Output , R₁ >
6002
)
20 Hz - 20 kHz
10
Hz
-
20
Hz
,
20 kHz - 50 kHz
50 kHz 100
kHz
SYNC OUTPUT
Signal
-
Impedance
INTERMOD
TEST
SIGNAL
Signal
LF
Frequency
Level
Typical
Residual
IMD
Table
1-1 (
cont )
Performance
Requirements
FRONT
PANEL
(
cont )
0.5
%
mismatch of
output
open -
circuit
voltages
referenced to
CT .
< 0.0008 % ( -102 dB ) THD
<
0.0018
%
( -95
dB ) THD
<
0.0056 % (
-85
dB )
THD
Sine wave with
same
frequency as
OUTPUT
.
200 mV rms ±
20 % to 20 kHz ;
at least
120 mV rms at 100 kHz .
LF sine wave mixed with normal oscillator
output in a 4 ( ± 0.1 ) to 1 amplitude ratio .
Internally selectable 60 Hz ( ± 2 % ) or
250
Hz (
+ 2
% ) .
Composite peak - to - peak output is within
± 0.2 dB of the normal oscillator mode sine
wave
output
.
Specification -
SG 505
Opt
.
02
Supplemental
Information
< 0.5 %
of
output
ac
rms
voltage
.
+25 V peak , CT to GND .
Typically
0.0003
%
THD
THD is typically < 3 % and phase shift from
OUTPUT is typically ≤ 5 ° , 20 Hz to 20 kHz .
Nominally 1 ks ,
ground
referenced and
isolated
from
main
output
.
With
oscillator set for 7
kHz test
signal
conforms with
SMPTE
recommendation
.
SYNC
OUT
signal is
low
frequency
component
only .
0.0005 % from 2.5 kHz to 10 kHz and
0.001 % from 10 kHz to 20 kHz .
1-3

Specification
- SG
505
Opt
.
02
Characteristics
Buffered
Main
Output
Sync
Output
1-4
Characteristics
Power Consumption
Internal
Power
Supplies
+17
V
- 17 V
Fuse Data
Recommended
Adjustment
Interval
Warm
-
up
Time
Table 1-1 (
cont
)
Performance
Requirements
REAR
INTERFACE
Table 1-2
MISCELLANEOUS
Performance Requirements
Supplemental
Information
Pins 25A and 26A . To prevent possible
instrument
damage
, do not
float
output in
excess of
± 25 V
peak
.
Output
impedance is
approximately
600
2. For
specified
distortion
performance of the
front panel
main
output , the
rear
interface load
impedance
must be
1 km2 .
This
output is
intended to
provide
an ac
signal
level
reference
for gain
measurements
. THD
is
typically
<
0.03 %
for
frequencies
<
20
kHz .
Pins 25A and 26A are balanced and floating ;
25A
is
inverted from
+
output , 26A
inverted
from
output
.
Signal
is
attenuated
20 dB
and
buffered from the actual output signal at the
front
panel
connector
.
Pins 27B and 28B ( ground ) . Approximately
200 mV rms sine wave identical to front panel
SYNC
output
signal .
Output
impedance
is
approximately 50
22 and
always
ground
referenced .
Supplemental
Information
15 VA or less .
Nominally
+17.0 V
± 3 %
Nominally
-17.0 V
±
5
%
3
AG ,
1A ,
250 V ,
fast
blow
2000
hours or 12
months
20 minutes ( 60 minutes after storage in high
humidity
environment ) .
●

Characteristics
TEMPERATURE
Operating
Nonoperating
HUMIDITY
ALTITUDE
Operating
Nonoperating
VIBRATION
SHOCK
BENCH HANDLING
PACKAGED PRODUCT
VIBRATION AND SHOCK
ELECTROSTATIC
IMMUNITY
ELECTROMAGNETIC
COMPATIBILITY
Characteristics
FINISH
NET
WEIGHT
° C to + 50 ° C
-40 ° C to + 75 ° C
95
% RH , ° C
to 40 ° C
45 % RH , to 50 ° C
4.6 km (
15,000
ft )
15 km (
50,000 ft )
NOMINAL
OVERALL
DIMENSIONS
Table 1-3
ENVIRONMENTAL
0.38 mm ( 0.015 " ) peak to peak , 5 Hz to
55
Hz , 75 minutes
.
30
g's ( 1/2
sine ) , 11 ms
duration ,
3 shocks in
each direction along 3 major axes , 18 total
shocks .
12 drops from
45 ° , 4 " or
equilibrium
,
whichever occurs first .
Qualified under National Safe Transit
Association
Preshipment Test
Procedures
1A - B - 1 and 1A - B - 2 .
20 kV
maximum
charge
applied
to
instrument
case .
ENCLOSURE TYPE
AND STYLE
Description
Within limits of F.C.C. Regulations , Part 15 ,
Subpart J , Class
A ; VDE
0871 ; and
MIL
461A tests RE01 , RE02 , CE01 , CE03 , RS01 ;
RS03 ,
CS01 ,
CS02 , and
CS06 .
Plastic
front
panel .
aWith
power module
.
Refer to TM 500/5000 power module specifications .
Without
power
module .
dRequires
retainer clip
.
*
System performance
subject to exceptions
of power
module or other
individual plug
- ins .
Qualified for CS02 and
CS06 in TM
5000
Series power modules with front - panel ground post or power module chassis strapped to ground .
1.13 kg ( 2.49
lbs . )
Meets MIL - T - 28800C , class 5 .
Specification - SG 505 Opt . 02
Exceeds MIL - T - 28800C , class 5 .
Exceeds MIL - T - 28800C , class 5 .
Meets MIL - T - 28800C , class 5 , when installed in
qualified
power
modules.b
Meets MIL - T - 28800C , class 5 , when installed in
qualified
power
modules.b
Table 1-4
PHYSICAL CHARACTERISTICS
Meets MIL - T - 28800C , class 5 when installed in
qualified
power
modules.b
Description
MIL
- T -
28800C
,
type 3 , style
E
package
with
power module
. ( Style F in
rackmount
power
module
. )
67.06 mm ( 2.64 " ) W x 308.36 mm ( 12.14 " ) D x 126.24 mm ( 4.97 " ) H .
1-5

●

O
OPERATING INSTRUCTIONS
Preparation
for
Use
The SG 505
Option
02
Oscillator
is
calibrated and ready for
use
when
received
.
It
operates in any
compartment of a
TM 500
or TM
5000
Series
power
module
.
Refer
to
the
power
module
instruction
manual
for line
voltage require
ments
and
power
module
operation
.
The SG 505
Option 02
instrument
has
an
intermodulation
test
function that mixes
a 60 Hz or
250 Hz sine
wave with
the selected output frequency . This signal is available at the
BALANCED
OUTPUT
connectors
.
The SG
505
contains an
internal
switch
that
sets the
lower
frequency of the
mixed
sine
wave
to 60
or 250
Hz .
The
instrument is
shipped
with
the
switch
in
the 60
Hz
position .
Refer
qualified
service per
sonnel to the
Maintenance
section
of this
manual
for
internal
switch setting information .
CAUTION
To prevent damage to the SG 505 circuitry , turn off
the
power
module
before
installing
or
removing the
instrument
.
Do not
use
excessive force to
install
or
remove .
Check
to
see that
the
plastic
barriers on the
interconnecting
jack of the
selected power
module
compartment match the
cutouts in the SG
505
circuit board
edge
connector .
Align
the SG
505
chassis with
the
upper and
lower guides ( see
Fig . 2-1 ) of the selected compartment . Push the SG 505
chassis
in
and press
firmly
to
seat the
circuit board edge
connector in the
interconnecting jack .
Turn on
the
power
module power switch . The POWER indicator on the front
panel
should
light
up .
To
remove the SG
505 , pull on
the
release
latch (
located
in
the
lower left
corner
) until
the
interconnecting jack
disen
gages and
the SG
505
slides out .
Section 2 -
SG
505 Opt . 02
POWER
MODULE
Interconnecting Jack
Barrier
Bottom
Groove
/
Top Groove
Slot
PLUG - IN
Latch
Knob
1431-21
Fig . 2-1 . SG 505 Option 02 installation and removal .
Repackaging
Information
If the Tektronix instrument is shipped to a Tektronix Service
Center
for
service
or
repair ,
attach a tag
showing owner
( with
address ) and the
name of an
individual
at
your firm to
contact . Include the complete instrument serial number and
a description of the service required .
Save and reuse the package in which the instrument was
shipped . If the original packaging is unfit for use or not avail
able , repackage the instrument as follows :
Surround
the
instrument with
polyethylene
sheeting to
protect the
instrument
finish .
Obtain a carton
of corru
gated
cardboard of the
correct
carton
strength
having
inside dimensions of no less than six inches more than
the
instrument
dimensions .
Cushion
the
instrument by
tightly packing three inches of dunnage or urethane
foam
between carton and
instrument
on
all sides .
Seal
the carton with
shipping
tape
or an
industrial stapler .
The carton test strength for this instrument is 200 pounds
per
square
inch .
2-1

Operating
Instructions -
SG 505
Opt .
02
CONTROLS
AND
CONNECTORS
FREQUENCY
SELECTION
1 )
FREQUENCY Hz
Provides
continuous frequency
selection
within
each fre
quency
range
selected
by
multiplier
pushbuttons .
2
)
Multiplier
Pushbuttons
Select any one of four frequency ranges .
3 )
VERNIER
Adjusts
frequency
up to ±
1 %
from selected
frequency
.
OUTPUT
LEVEL
SELECTION
4
OUTPUT
LEVEL
dBm
into
600
A
Selects one
of ten
amplitude
level steps ,
calibrated
in
dBm
into
a 600
load with
SOURCE
R set
to 600
.
5
OUTPUT LEVEL
CAL
Provides
continuous
amplitude
adjustment
from the
calibrat
ed
OUTPUT
LEVEL
steps
.
Range is
nominally
+0.7
dB
to
<
-10 dB
relative
to the
clockwise CAL
detent .
6
SOURCE R
Selects 50 , 150 , or 600 source impedance . Impedance to
the CT terminal is one - half the selected source impedance .
7
) INTERMOD
TEST SIG
Pushbutton
in provides
a 60 Hz or
250 Hz sine
wave
mixed
with
any
selected
output
frequency in a 4
: 1 amplitude
ratio .
Also
provides a
60 Hz
or 250
Hz
signal at the
SYNC
OUT
connector . See
Preparation
for Use
for frequency
selection
information .
8 ON - OFF
Connects or
disconnects
the signal to
the
BALANCED
OUTPUT
connectors ( does
not switch CT
terminal ) . The
se
lected
source
impedance
is
retained at
the
BALANCED
OUTPUT connectors regardless of pushbutton position .
2-2
9
)
GND -
FLTG
GND
connects
the
CT (
common
)
connector to
chassis
ground
through
a
low
impedance .
FLTG
disconnects
the CT
( common
) from
chassis
ground
for
floating
operation . Do
not exceed
±
25 V
peak
floating
potential
between
the
CT
connector
and
chassis
ground
.
OUTPUT
CONNECTORS
10
BALANCED
OUTPUT
The
+
BALANCED
OUTPUT
connector
provides a
sine
wave
signal
with
the
frequency
selected
by
the
FREQUENCY Hz
dial and
multiplier
pushbuttons
and the
amplitude
selected
by
the
OUTPUT
LEVEL
control
. The
-
BALANCED
OUTPUT
signal is an
inverted
duplicate
of the
+
BALANCED
OUTPUT .
Also
see
INTERMOD
TEST
SIG
(
7 ) .
CT
The CT
connector
provides
the
reference
point for
the
+
and
BALANCED
OUTPUTS
. The CT
connector
can
be
floated
above
ground
or
ground -
referenced
with the
GND
FLTG
pushbutton ( see 9 ) .
11 SYNC
OUT
Provides
a
fixed -
amplitude
and ground
-
referenced
sine
wave
at
the same
frequency
as
the
BALANCED
OUTPUT
signal
.
This
signal
is in
phase
with
the +
BALANCED
OUT
PUT .
Also
refer
to
INTERMOD
TEST SIG
( 7 ) .
12
Ground
Binding Post
Chassis
ground .
13
Release
Latch
Pull to
remove
plug - in
from
the power
module .
14
POWER
Indicator
Indicator
lights
when
power
is
applied to
instrument
from
power
module
.

3
6
4
1
(
11
)
13
+
SOURCE R
INTERMOD
TEST SIG
LF + FREQ
MIXED 4 : 1
ON
SYNC OUT
SG
505
OSCILLATOR
VERNIER
SL
O1
8
50
600
Tektronix
-18
-28
2
-38
OUTPUT
LEVEL A
dBm
INTO
-8
+12
CAL
-58
FREQUENCY Hz
2.5
+
CT
-48 -68
BALANCED OUTPUT
+22
2
+ 28
Rs
=
500
UNCAL
X10k
X1k
Operating
Instructions -
SG 505 Opt
. 02
X100
-25Vpk .
X10
ON
M ...
POWER
GND
FLTG
DOL
Ú
Fig
. 2-2 .
SG 505
Option
02
front panel
controls
and
connectors
.
14
1
2
5
8
9
10
12
4359-02
2-3

Operating Instructions - SG 505 Opt . 02
OPERATORS FAMILIARIZATION
General Operating Information
With the
SG 505
properly
installed
in the
power
module
, al
low twenty minutes warmup time for operation to specified
accuracy
( 60
minutes
after
storage
in or
exposure
to a high
humidity
environment
) .
Frequency
Selection
The
SG
505
produces a
sine wave
signal at
any frequency
from 10 Hz
to
100
kHz
.
To set
the
frequency ,
press the
ap
propriate multiplier pushbutton and set the FREQUENCY
Hz dial to the desired base frequency . The VERNIER control
adjusts the frequency 1 percent above and below the fre
quency selected by the FREQUENCY Hz dial and multiplier
pushbutton . With the VERNIER control at the center posi
tion , the output frequency produced is the FREQUENCY Hz
dial setting
multiplied
by the
active
multiplier value . Signals
at the BALANCED OUTPUT and SYNC OUT connectors
are of the
same
frequency
. The
SYNC
OUT
signal
can
be
used as
an
external
signal
for
monitoring the
frequency
of
the
BALANCED
OUTPUT ,
provided no
more than
approxi
mately 200 mV rms
is
required .
Output
Level
Selection
A
The
OUTPUT
LEVEL
selects
ten
level steps
from +22
dBm
to 68 dBm
into a 600
load with
SOURCE
R set
to
600 2. If
SOURCE
R is
set to 50
, the level
will
increase by
about 5.3 dB
into 600 2. If
SOURCE
R is
set to 150 ,
the
output
level
into a 150
load is
exactly 6 dB higher
than the
levels marked on
the panel . The
OUTPUT LEVEL CAL con
trol permits continuous adjustment from the calibrated out
put level steps over the range of approximately +0.7 dB to
< -10 dB
from CAL .
The signal at
the
BALANCED OUT
PUT
connectors may
be
ground
referenced or
floated up to
25 V peak , using the GND - FLTG pushbutton . The ON - OFF
pushbutton connects or disconnects the signal at the BAL
ANCED
OUTPUT
connectors .
Intermodulation
Test
Signal
With the
INTERMOD
TEST
SIG
pushbutton in , a 60
Hz or
250 Hz sine
wave is
mixed
with
any
selected
frequency at
the
OUTPUT
connectors in a 4 : 1
amplitude
ratio . The
com
posite
peak
- to -
peak
amplitude is set
equal
to
the peak -
to
peak amplitude of the unmodulated OUTPUT signal .
In the
INTERMOD
TEST SIG
mode
,
the
SYNC OUT
con
nector
provides only the 60 or
250 Hz sine
wave .
2-4
Output
Connections
CAUTION
To avoid
damage
to the
SG 505
circuitry
, do not
apply
a voltage exceeding ± 25 V peak , with respect to
chassis ground , to any front panel connector or to
rear interface connector pins 14A - 28A and 14B - 28B .
The SG 505 Option 02 is designed primarily as a balanced
source of low distortion sine waves . Thus , it is intended to
be used in systems where the load is also balanced or differ
ential . The
balanced configuration is
preferable in high quali
ty audio applications because of its inherently superior
rejection of common mode signals , such as induced hum or
RF voltage . See Fig . 2-3A and 2-3B . The SG 505 Option 02
can also be
used to drive
unbalanced
or
single - ended
loads
if the output is taken using either the + or - BALANCED
OUTPUT connector as the high side and the CT connector
as the low . In this mode , the output voltage and the source
resistance
are
both half the
calibrated
or
selected
values .
See Fig . 2-3E . Driving unbalanced loads from the full bal
anced
output
is not
recommended
because
of
possible deg
radation due to
common
mode
signals such as
power
line
hum or noise
spikes
coupling across one - half of
the
output
resistance
. See
Fig . 2-3C . Even
when the SG
505 is floating ,
unavoidable stray capacitances within the instrument and
those associated with external cabling can cause small
amounts
of
these common mode
signals to
couple to the
load . The coupling magnitude is independent of the oscilla
tors
output attenuation
and will
become
progressively
worse as output amplitude is reduced . Thus , the common
mode noise may dominate any distortion products in the
system , especially at lower output levels . The stray capaci
tance can also adversely affect high frequency flatness . If
the SG 505
GND - FLTG
pushbutton
selects GND in this
con
figuration , then half the output voltage is short - circuited .
See Fig . 2-3D . To minimize the contribution of these com
mon mode signals , it is recommended that the SG 505 not
be
operated
in
the high
power
compartment of any TM
500
or TM 5000
series
power
module
.
These
compartments
provide higher power series - pass transistors with substan
tially higher stray capacitance to chassis , which couples
larger amounts of common mode signals into the SG 505 .
The GND - FLTG pushbutton either connects the CT connec
tor ( common ) to chassis ground through approximately 30
or
disconnects
the CT
from
chassis
ground .