Tektronix 7D14 User manual

TEKTRONIX
R
7D14
DIGITAL
COUNTER
S / N
B050000
and
up
INSTRUCTION MANUAL
Tekt ronix
, Inc.
P.O. Box 500
Beaverton , Oregon 97005
Serial Num ber
070-1663-00
973

WARRANTY
W
All
TEKTRONIX
instrum ent s
are
warrant ed against
defective
m at erials and
work m anship for one
year .
Any
quest ions wit h respect to the warrant y should be taken up
wit h your TEKTRONIX Field Engineer or represent at ive .
All request s for repairs and replacem ent part s should be
directed to the TEKTRONIX Field Office or represent at ive
in your area . Thi s will assure you the fast est possible
service . Please include the instrum ent Type Num ber or Part
Num ber
and
Serial
Num ber
wit h
all
request s for part s or
service .
Speci fications and price change privileges reserved .
Copyright
1971
,
new
m at erial
1973 , by
Tekt ronix
,
Inc. ,
Beaverton ,
Oregon .
Printed in
the
Unit ed States
of
Am eri ca . All rights reserved . Content s of this publicat ion
m ay not be
reproduced
in any
form
wit hout
perm i ssi on of
Tekt ronix , Inc.
U.S.A. and foreign TEKTRONIX products covered by U.S.
and foreign patents and / or patents pending .
TEKTRONIX is a regi stered t radem ark of Tekt ronix , Inc.

7D14 ( SN
B050000
&
up )
TABLE OF CONTENTS
SECTION 1
SPECIFICATION
Introduct ion
Electrical Characterist ics
Environm ental
Characterist ics
Physical
Characterist ics
Page
1-1
1-1
1-5
1-5
SECTION 2
OPERATING INSTRUCTIONS
Installation
Display
Controls and Connectors
First -
Tim e
Operat ion
General Operat ing Inform at ion
Measurem ent Modes
Operat ing
Modes
2-1
2-1
2-1
2-4
2-5
2-8
2-10
SECTION 3
CIRCUIT DESCRIPTION
Introduct ion
Block
Diagram
Descript ion
Detailed
Circuit
Descript ion
3-1
3-1
3-3
SECTION 4
MAINTENANCE
Introduct ion
Prevent ive Maint enance
Troubleshooting
Replacem ent
Parts
Com ponent
Replacem ent
4-1
4-1
4-1
4-4
4-4
SECTION
5
CALIBRATION
Recalibration Interval
Test Equipm ent Required
Part 1 - Perform ance Check
Part II 
Adjust m ent
5-1
5-1
5-5
5-13
-
SECTION 6
ELECTRICAL PARTS LIST
Abbreviations and
Sym bols
Parts
Ordering
Inform at ion
SECTION 7
DIAGRAMS
AND
CIRCUIT
BOARD
ILLUSTRATIONS
Sym bols and Reference Designat ors
Voltage
and
Waveform
Condit ions
7-1
7-2
SECTION 8
MECHANICAL PARTS LIST
Mechanical Parts
List
Inform at ion
Index of
Mechanical Parts
Illust rat ions
Mechanical
Parts
List
Accessories
8-1
CHANGE
INFORMATION
Abbreviations and sym bols used in this m anual are based on or taken directly from IEEE
Standard 260
" Standard
Sym bols for Unit s
 , MIL - STD - 12B
and ot her
standards of the
elect ronics
industry . Change
inf orm at ion , if any
, is locat ed at
the rear of this
m anual .
  )
i

MEASUREMENT
INTERVAL
TRIGGER
LEVEL
/
SLOPE
1 m s
GATE
10
m s
100
m s
PRESET
VAR
MONITOR
15
INPUT
SENS
P -
P
VOLTS
10 s
EXT
GATE
TRIG
SOURCE
100
m V
ON
MANUAL
GATE
 
100 m V
5002
1V
1V
1 
10
V
OFF
]
-RESET
BW
COUPLING
DISPLAY
TIME
INCREASE
525
MHz
AC
5
MHz
DC
5 s
00
CH
A
INPUT
525
MHz
MAX
REF
FREQ
/
CH
B
INT
MONITOR
1
MHz
5022
10V
RMS
MAX
IMS
20pF
200V
PK
MAX
EXT
IN
TEKTRONIX
DIGITAL
COUNTER
7014
Fig . 1-1 . 7D 14 Digit al Count er Plug - in Unit .
7D14
A

2
Sect ion
1-7014
(
SN
B050000
&
up )
SECTION 1
SPECIFICATION
Change
inf orm at ion , if
any ,
affect ing this
sect ion will be
found at the
rear of this
m anual .
Introduct ion
trigger
pickoff
from
vert ical am pli fier
unit (
which
allows
sim ult aneous
signal
viewing
and
count ing
,
and a
trigger
indicat or
analog
CRT
display to
view
the "
shaped "
input
signal .
n
The 7D 14
Digit al
Count er
plug - in
unit
is
designed for
use
wit h
Tekt ronix
7000
-
series
Oscilloscopes
equipped
wit h
readout
syst em . The
7D14 uses the
readout
syst em to
display an eight - digit readout on the CRT of the associ at ed
oscilloscope
.
The
7D14 will
m easure
frequency
from to
525
m egahert z
,
frequency
rat io
from to 105
: 1
and
tot alize (
count
num ber
of
event s )
from to
108.
The
7D 14
feat ures
count ing
capability
to
525
m egahert z
wit hout
prescaling , input im pedance of 50 ohm s or 1 m egohm ,
blanking of all
zeros
to the
left of the
m ost
significant digit ,
C
The following elect rical characterist ics are valid for
instrum ent s
calibrat ed at an
am bient t em perat ure
between
+
20  C
and
+
30 
C
aft er a
20
m inut e
warm up
period .
1
TABLE 1-1
ELECTRICAL
Characterist ic
Perform ance
Requi rem ent
Supplem ent al Inform at ion
CHANNEL A (
Count Channel )

7
INPUT SENS
P - P
VOLTS
Swit ch
Setting
50 12
1
MS2
Frequency
Range
n
DC
Coupled
DC
to
525
m ega
hertz
DC
to
525
m ega
hertz

AC
Coupled
200
kilohert z to
525
m egahert z
5 hertz
to 525
m egahert z
Sensit ivity
Com
100 m illivolt s
peak - to -
peak
100 m illivolt s
peak - to - peak
Input

Resistance
As indicat ed by INPUT SENS Swit ch
wit hin 10 % .
VSWR in 50 -
ohm
position
<
1.5
: 1
n
Capacit ance Not
applicable
20 picofarads wit hin 20 % when INPUT
SENS
is
set to 1 M2
input
im pedance .
C

 
1-1

co
Speci fication
-
7014 (
SN
B050000
&
up )
TABLE
1-1
(
cont . )
U
Characterist ic
Perform ance
Requi rem ent
Supplem ent al
Inform at ion
Maxi m um
Input
Voltage
10
volt s
RMS
200
volt s
( DC
+
Peak AC ) to 5
m egahert z
.
50
volt s ( DC + Peak
AC )
to
525
m ega
hertz
U
L
U
TRIG SOURCE
Sensit ivity
1.5
divisions of
vert ical
deflect ion
m ini m um
I
Frequency Range
TRIG
SOURCE is AC
coupled
.
Depends
upon
am pli fier
plug - in
unit
and oscilloscope being used .
U
BW
-
5
MHZ
Li m it s upper bandwidth ( -3 dB poi nt )
to 5 m egahert z wit hin 1 m egahert z .
C
Trigger
PRESET
Triggers
on the
positive
slope at
volt
level
.
C
VAR LEVEL SLOPE
control
select s
positive or
nega
tive
slope triggering .
a
Range
INPUT
SENS Swit ch
Setting
U
100 m V
+0.5 volt to
-0.5 volt
1 V
+5 volt s to -5 volt s
-
10V
+50 volt s to -50 volt s
CCC
MEASUREMENT INTERVAL
Internal
Tim e
Base
U
Crystal
Oscillat or
Frequency
5
m egahert z
Co
Accuracy
 C to +
50  C
Within 0.5 part per m illion
U
Long
Term
Drift
1 part
or
less in
107
per m onth
U
1-2
 )
U

C
Speci fication -
7014
( SN
B050000 & up )
n
TABLE 1-1
(
cont
.
)
C
Characterist ic
Perform ance
Requi rem ent
Supplem ent al
Inform at ion
Internal Gate
Range
1 m illisecond through 10 seconds
Select able in
decade
steps
C
Resolut ion

7
Up
to 0.1
hertz
Accuracy
1
Within
+
+
Tim e
Base
Accuracy
Tot al
Count
CH B
n
Frequency Range
10
hertz
to 2
m egahert z
AC
Coupled
Only
At
least 0.8
volt
peak
-
to -
peak
Sensit ivity
C
Sine wave or pulse wit h 30 % -70 % duty
cycle
Input
R
10 kilohm s wit hin 20 %
C
30
picofarads
wit hin
30 %
C
Max
Input
Voltage
50
volt s
(
DC +
Peak AC ) to
2
m ega
hertz
EXT
GATE
Input Requi rem ent s
Com pat ible wit h TTL Logic .
Turn On Level
Logic
" l
" at least
+2 Volts
Turn Off Level
Logic " " +500 m illivolt s or less
Risetim e
500
nanoseconds (
Maxi m um )
Fallt im e
500
nanoseconds (
Maxi m um
)
Minim um
Off
Tim e
500 nanoseconds
C
C
C
C
Minim um On Tim e 200 nanoseconds
Propagat ion Delay
+ Transition
40 nanoseconds wit hin 20 nano
seconds
Transition
40 nanoseconds wit hin 20 nano
seconds
no
Input
Resistance
8.2
kilohm s wit hin
20 %
Capacit ance
35
picofarads
wit hin
20 %
C
C
C
1-3
A
n

U
Speci fication -
7014
( SN
B050000 &
up )
TABLE
1-1 (
cont . )
Characterist ic
Perform ance
Requi rem ent
Supplem ent al
Inform at ion
EXT
GATE
(
cont
)
Max
Input
Voltage
+15
volt s
( DC
+
Peak AC ) to
10
m ega
hertz
U
DISPLAY TIME
Range
Continuously
variable from
0.1
seconds
or
less to at
least
5 seconds
U
Detent
Posit ion
oo (
infinite )
RESET
C
Input
Requi rem ent s
At
least 2
volt s
positive -
going
pulse
.
Am pli tude
Com pat ible wit h
TTL Logic
,
Logic " " +500
m illivolt s or less
C
Logic
"
1 " at
least
+2 volt s
C
Durat ion
At least 500 nanoseconds
Input
Resistance
8.2 kilohm s wit hin 10 %
Capacit ance 30
picofarads
u
Max
Input
Voltage
+20
volt s
(
DC +
Peak
AC
) to
10
m ega
hertz
OUTPUT SIGNALS
MONITOR
INT 1
MHZ
Signal
Posit ive - going pulse from int ernal
cryst al
oscillator
Am pli tude
C
C
C
C
C
Open
Circuit
5 volt s wit hin 10 %
Source
Im pedance
Logic
" O "
1 kilohm s
Logic
" 1
"
2.2
kilohm s
1
m s
10 s
Signal
Tim e
m arker
pulses
from
int ernal
gat e
.
Am pli tude
1
Open
Circuit
5
volt s
wit hin 10 %

1-4
A

Speci fication -
7014 ( SN
B050000
& up )
TABLE 1-1
(
cont . )
Characterist ic
Perform ance
Requi rem ent
Supplem ent al
Inform at ion
1
m s 10 s ( cont )
Polarity Posit ive -
going
Source
Im pedance
Logic
" O "
Z1 kilohm
Logic
"
1 "
25.7
kilohm s
CCC
C
C
C
C
C
C
C
Trigger
Indicat or
CRT
analog
display
of
trigger
output
Display
Am pli tude
0.2 div wit hin 25 %
Posit ion
Range
Posit ionable over 8 div by int ernal
control
Usable
Frequency
Range
System
Dependent
Signal Delay
25 nanoseconds
TABLE
1-2
TABLE
1-3
ENVIRONMENTAL CHARACTERISTICS
PHYSICAL
Refer
to
the
Speci fication
for the
associ at ed
oscillo
Size
Fit s all
7000 -
series
plug
- in
com partm ent s .
Weight 2 Pounds 6 Ounces ( 1075 gram s )
scope .
C
C
n
C
C
n
C
C
C
A
1-5

(
C
C
C
C
C
C
C
C
a
(
C
C
C
C
C
C
C
C
C
C
C

Sect ion
2 7D14 ( SN
B050000 & up
)
SECTION 2
OPERATING
INSTRUCTIONS
Change
inf orm at ion
, if
any ,
affect ing this
sect ion will be found
at the rear of
this
m anual
.
General
digital display . However , in order to view the 7D 14 Trigger
Indicat or Display , select ion wit h the Vert ical Mode switch
is
required
.
The 7D 14
Digit al
Count er
plug -
in unit
operates
wit h
the
readout syst em of
Tekt ronix 7000 - series
Oscilloscopes to
m easure frequency or frequency rat io , and to tot alize
( count
num ber
of event s
) . To
effect ively use the
7D14 , the
operation and capabilities of the instrum ent should be
known . Thi s sect ion describes the function and operation
of the controls and connect ors , and gives first - t im e and
general
operating
inf orm at ion .
The readout display of the m easurem ent data consists of
four to eight digits depending on the m easurem ent being
m ade . All
zeros to the left of
the m ost
significant
digit are
blanked
out
.
Installation
The m easurem ent unit s and decim al position in the dis
play are det erm ined by the MEASUREMENT INTERVAL
pushbutton select ed . When the
m easurem ent range in use is
exceeded , the display is preceded by a " greater than "
sym bol > ) .
The 7D
14 is
designed to
operate
in
any plug - in
com part
m ent of
Tekt ronix
7000 -
series
oscilloscopes
.
However
,
certain m odes of operation require the 7D 14 to be installed
in a specific com partm ent . The unit m ust be operated in a
Horizontal com partm ent to count a signal which is being
displayed on the CRT ( see Count ing a Displayed Signal ) .
Operat ion in a Vert ical com partm ent is necessary to view
the 7D 14 Trigger Indicat or Display on the CRT ( see Trigger
Indicat or
Display ) .
CONTROLS AND CONNECTORS
The m aj or controls and connect ors for operation of the
7D 14 are locat ed on the front panel of the instrum ent .
These are shown in Fig . 2-1 . Two auxiliary functions are
provided by controls locat ed inside the instrum ent . A de
scription of the function and / or operation of the controls
and connect ors follows .
To
install the
7D14 int o a plug
- in
com partm ent ,
push
the unit in unt il it is seat ed flush against the front panel of
the oscilloscope . To rem ove , pull the release lat ch to dis
engage the 7D 14. Continue to pull the release lat ch to
rem ove the unit from the oscilloscope .
Measurem ent Interval Controls
MEASUREMENT
INTERVAL
Seven self -
cancelling
pushbutton
switches that
select
int ernal
,
ext er
nal , or
m anual
gat e .
Display
The digital readout display for the 7D 14 is present ed on
the CRT of the oscilloscope in which the unit is operated ,
along wit h inf orm at ion encoded by the ot her plug - in unit s .
Thi s display is writt en by the CRT beam on a t im e - shared
basis wit h
the analog
waveform displays .
1 m s - 10 s ( one
Select s
one
of five
m easurem ent
m illisecond through int ervals from the int ernal t im e
10 seconds )
base gat es . A t im e - m arker output
wit h a period equal to the select ed
int erval is provided at the MONI
TOR
connect or .
MANUAL GATE
The digital display for the 7D 14 will appear on the CRT
in a locat ion corresponding to the plug - in com partm ent
used . The m easurem ent data portion of the display will be
in the top division of the CRT grat icule area and the
m easurem ent unit s ( MHz or kHz ) , when displayed , will
appear
in the
bot tom
division
.
ON : Initiat es gat e int erval ( start
count ) , and
holds the gat e
open
for
tot alizing .
OFF : Term inat es gat e int erval ( stop
count ) , and starts display t im e .
Also select s ext ernal gat ing
signal from the EXT GATE con
nector .
GATE Indicat or
It is not
necessary
to
select the
7D 14
wit h the
oscillo
scope Vert ical
or Horizontal Mode
switches to
view the
Lights during the act ive gat ing
int erval
.
A
2-1

Operat ing
Instruct ions

7014 (
SN
B050000 &
up )
MEASUREMENT
INTERVAL
TRIGGER
LEVEL / SLOPE
1
m s
GATE
10
m s
100
m s
MONITOR
PRESET
VAR
15
INPUT SENS
P - P VOLTS
10 s
EXT
GATE
TRIG
SOURCE
100
m V
ON
7
100m V
5032
1V
1V
1 
10
V
MANUAL
GATE
Off
RESET
DISPLAY TIME
INCREASE
BW COUPLING
525 MHz AC
5 MHz
DC
0.15 58
00
REF
FREQ
/
CH B
CH A INPUT
525 MHZ MAX
INT
MONITOR
1
MHz
500
10VRMS
MAX
IMS2
20pF
200V PK
MAX
EXT IN
TEKTRONIX
DIGITAL
COUNTER
7014
Fig . 2-1 . 7D14
front - panel controls
and
connect ors
.
2-2
A

Operat ing
Instruct ions 
7D14 ( SN
B050000 & up
)
PRESET
EXT GATE / MONI
TOR
Connector
BSM connect or for ext ernal gat e in
put or t im e m arker output as
select ed by MEASUREMENT
INTERVAL
pushbuttons
.
Pushbutt on that select s a fixed trig
ger
poi nt at the
zero - volt
level on
the
positive -
going
slope (
LEVEL /
SLOPE
control inoperat ive ) .
VAR
Pushbutt on to allow m anual selec
tion of trigger level and slope wit h
the LEVEL / SLOPE control .
Display
Tim e
Controls
DISPLAY TIME
INPUT SENS / P - P
VOLTS
Rot ary switch that select s int ernal
or ext ernal signal input to trigger
count er and select s sensit ivit y .
Variable
control
to set
the lengt h
of
t im e the reading will be displayed
aft er the
count is m ade
and
before
the next
m easurem ent
is
taken . Dis
play t im e can
be
varied
from 0.1
second to five seconds . oo ( infinite )
position ( fully clockwise ) provides
continuous display unt il reset by an
ext ernal signal or by pressing the
RESET pushbutton .
5012
Input signal
provided from
CH A
INPUT connect or at 50 - ohm input
im pedance .
1 V :
Minim u m
signal
am pli tude
m ust
be
one
volt or
greater
.
100
m V
:
Minim u m
signal
am pli
tude
m ust be
100 m V or
greater .
RESET
Pushbutt on : Manually resets the
count er to zero .
Pin - jack
connect or
: Provides
input
for ext ernal
signal to reset
the
count er
to
zero .
1
MS2
Input
signal
provided
from
CH A
INPUT connect or at one - m egohm
input im pedance .
100 m V : Minim u m signal am pli
tude m ust be
100 m V or greater .
1 V : Minim u m signal am pli tude
m ust be one volt or greater .
10 V : Minim u m signal am pli tude
m ust be 10 volt s or greater .
Reference
Frequency /
Channel B
Controls
REF FREQ / CH B
Pushbutt ons that select the func
tion of the EXT IN / MONITOR
connect or .
TRIG
SOURCE
INT 1 MHz
(
Internal
1
m ega
hertz
)
Select s 1 MHz
signal from
int ernal
cryst al oscillator at MONITOR con
nector
.
Input
signal
provided
from
the
indi
cat or
Oscilloscope
trigger
pickoff
circuitry
. ( Thi s
m ode of
operation
enables sim ult aneous count ing and
CRT display of a signal . For m ore
inf orm at ion
, see
Count ing a
Dis
played Signal . )
EXT IN
(
ext ernal
input )
Select s ext ernal
input to Channel
B
for an ext ernal t im i ng standard , or
for signal input for rat io m easure
m ent s .
BW ( bandwidth )
Trigger
Controls
LEVEL
/
SLOPE
Pushbutt on switches that select the
bandwidth of the trigger input cir
cuit s
(
affect s
signals
from
int ernal
TRIG
SOURCE and
CH A
INPUT
connect or
) .
525 MHz : Select s
full
bandwidth
capability .
5 MHz : Li m it s upper bandwidth to
about
5
m egahert z ( -3
dB
poi nt ) .
Select s the am pli tude poi nt and
slope
on
trigger
signal
where
count er is triggered ( VAR push
butt on
pressed )
. When the
indicat or
line on the outer
ring is to the
left
of center , the count er is triggered
on the
positive -
going
slope of the
input
signal as
shown
by the
positive - going
edge
sym bol .
To the
right of
center , the
count er is trig
gered on the
negat ive - going
slope of
the
input
signal as
shown by
the
negat ive - going edge sym bol .
COUPLING
Pushbutt on
switches
that
select the
m ethod
of
coupling the
signal
from
the CH A INPUT connect or to the
trigger
circuits
( does
not
affect sig
nals from
int ernal
TRIG
SOURCE ) .
 
2-3

Operat ing
Instruct ions -
7D14
(
SN
B050000 &
up )
The
following
First -
Tim e
Operat ion
procedure
dem on
strat es
the
basic
operation
of
the
7D14
controls
. It
is
recom m ended
that
this procedure
be
followed
com pletely
for
fam iliari zat ion
wit h the
instrum ent
.
   



QO0000
OQQ6090009
933
G
UM
60
$
780N
840
54
0122013
$ 2493
NOTE
191
70082
SEA
1801
14923
16
Display
Pos
R866
09
Manual
Gate
Storage
Swit ch
The
First
-
Tim e
Operat ion
procedure
along
wit h
Table
2-1 can be
used to
provide
a
confidence
check
of
the
instrum ent ’s
operation .
These
steps
should be
per
form ed
each
t im e
the 7D14
is
placed
in a
different
oscilloscope
,
and
before
each
use
.
NIGTES
1537
192200
9783184
x
4.9
OTO
NICO
OR
***
239
XD
Preli m inary
Instruct ions
1.
Install
the 7D
14 in
any available
plug - in
com part
m ent
of a
7000 -
series
oscilloscope
( referred
to
in
this proce
dure as the
Indicat or
Oscilloscope
) .
Fig . 2-2 . Manual
Gate Storage switch
and Display
Pos adjust m ent
.
2. Connect
the oscilloscope
to a power
source which
m eet s the
frequency
and
volt age
requirem ent s
of the
Indi
cat or Oscilloscope power supply .
AC :
Select s
capacitive
coupling
to
block DC signal com ponents .
This switch
position
is
used for
m ost signal
m easurem ent s .
DC : Select s
direct
coupling to pass
all
com ponents
of
the signal
from DC
to the
upper li m it
of
the unit
. This
switch
position is
used
m ai nly
for
DC
and
low
frequency
signals .
3.
Turn
the
oscilloscope
power
on
and
allow
about
twent y
m inut es
warm up
t im e .
4.
During the
warm up
period ,
set the
controls
as
follows :
INDICATOR
OSCILLOSCOPE
CH A
INPUT
( BNC
connect or )
Input
connect or
for
external
signals .
Intensit y
Readout
Count erclockwise
Off
Internal Controls
Any controls
not
m ent ioned
can be
set as
desired
.
See Fig . 2-2
7D14
Man
Gate
Storage
Slide
switch
Select s m anual gat e storage m ode
( use wit h MANUAL or EXT GATE ) .
OFF ( forward ) : Readout display
follows the count er .
ON ( rear ) : Readout display is up
dated at
the end of
each gat e
int erval .
MEASUREMENT
INTERVAL
DISPLAY TIME
REF FREQ / CH
B
TRIGGER
INPUT SENS / P - P VOLTS
BW
COUPLING
10
s
Midrange
INT 1
MHz
PRESET
1 MS2 / 1
V
5
MHZ
AC
Display
Pos
Variable
control
to set
the
Trigger
Indicat or Display vert ical
position
.
FIRST - TIME
OPERATION
Digit al
Display
Check
5. Advance
the Readout
control unt il
a readout
display
is observed
. Adjust the
oscilloscope
Focus and
Ast igm at ism
controls for a
well -
defined
display
.
General
When
shipped
from the
factory
, the 7D
14 has
been
cali
brated
to m eet
the
specifications
listed in
Section 1
and is
ready
to
be used
wit h
a
readout - equipped
Tekt ronix
7000 -
series
Oscilloscope .
6.
Connect the
1
MHz signal
from
the
EXT IN /
MONITOR
connect or
to the CH
A INPUT
connect or
wit h a
BSM m ale
to BNC
fem ale
adapter and
a 50 - ohm
BNC
cable
.
2-4
 )

Operat ing
Instruct ions
- 7014 ( SN
B050000 &
up )
7. The readout display should read 1000.0000 kHz +1
count ( 999.9999 to 1000.0001 kHz ) .
A signal can also be rout ed to the 7D 14 through an am
plifier unit in a vert ical plug - in com partm ent via the int ernal
trigger pickoff circuitry of the Indicat or Oscilloscope . Thi s
m ethod of signal connect ion m ini m izes circuit loading for
m easurem ent s requiring sim ult aneous count ing and CRT
display ( see Count ing a Displayed Signal ) .
8.
Check
that
the GATE
indicat or
light
is
on
during
the
t im e
the
7D14 is
count ing ( 10
seconds ) .
9. Sequent ially press the MEASUREMENT INTERVAL
1 s through 1 m s pushbuttons and check that the display
corresponds to the readings given in Table 2-1 .
TABLE
2-1
General
Control
Settings
Introduct ion
.
The
following
discussion
provides
control
setup
inf orm at ion
for
general
m easurem ent
applicat i ons
.
Furt her inf orm at ion can be found under Controls and Con
nectors or in the discussion for a specific m easurem ent
m ode ( e.g. , Frequency Measurem ent s ) .
OPERATING CHECK DISPLAY
MEASUREMENT
INTERVAL
READOUT LIMITS
MINIMUM MAXIMUM UNITS
10
s
1s
100
m s
10
m s
1
m s
999.9999
999.999
0.99999
0.9999
0.999
1000.0001
1000.001
1.00001
1.0001
1.001
kHz
kHz
MHz
MHz
MHz
Trigger Controls . Signals to be count ed m ay have a wide
variety of shapes and am pli tudes , m any of which are unsuit
able to drive the count ing circuits . For this reason , the
signals are first applied to signal conditioning circuits ; then
to the
trigger circuit ,
where they are
convert ed
to
rectangu
lar pulses of uniform am pli tude .
10. Disconnect the cable and the adapter .
GENERAL OPERATING INFORMATION
Signals often
have
characterist ics which
would prevent
triggering or result in an errat i c count . These signals m ust
be
conditioned
before they are
applied
to
the
trigger input .
The INPUT SENS , COUPLING , and BW switches provide
m eans of conditioning the trigger signal . Obtaining a steady ,
reliable
reading
is
dependent
upon
the
proper
setting
of
these controls and proper adjust m ent of the LEVEL /
SLOPE control .
Signal
Connection
In general , probes offer the m ost convenient m eans of
connect ing signals
to the 7D14
CH A INPUT .
Tekt ronix
probes are shielded to prevent pickup of elect rostat ic int er
ference . A 10X at tenuation probe offers a hi gh input
im pedance and allows the circuit under test to perform very
close to norm al operating conditions . Also , a 10X probe
at tenuates the input signal ten t im es .
The INPUT SENS / P - P VOLTS switch select s eit her int er
nal rout ing of the signal from the Indicat or Oscilloscope
trigger
circuitry or
connect ion
through
the CH
A INPUT
connect or . Operat ion in the TRIG SOURCE position
requires that the 7D 14 be installed in a horizontal plug - in
com partm ent
. The
oscilloscope
Trigger
Source
switch for
that horizontal channel then provides further select ion of
the signal source . ( For m ore inf orm at ion on this m ode of
operation , see
Count ing a
Displayed Signal . )
Tekt ronix probes are designed to m onitor the signal
source wit h m ini m um circuit loading . The use of a probe
will , however , li m it the m axi m um bandwidth capability of
the 7D14 . To obt ain m axi m um bandwidth when using
probes , use a probe capable of com pensat ing 20 pF ; use one
of the 1 M12 input im pedance positions of the INPUT
SENS / P - P VOLTS switch ; and observe the grounding con
siderat ions given in the probe m anuals . The probe - to
connect or adapters and the bayonet - ground tip provide the
best
frequency
response .
For signals connect ed to the CH A INPUT connect or , set
the INPUT SENS / P - P VOLTS switch to select the desired
input
im pedance . An input
im pedance of
50 12 should be
used when coupling int o a 50 - ohm syst em for hi gh
frequency m easurem ent s . The 1 MS2 settings provide a
hi gher input im pedance for m ini m izi ng loading on the
signal source .
In hi gh - frequency applicat i ons requiring m axi m um over
all bandwidth , use a coaxial cable for the signal connect ion
and a 50 2 input im pedance position of the INPUT
SENS / P - P
VOLTS
switch . To
m ai nt ain
the
hi gh -
frequency
characterist ics of the applied signal , use hi gh - quality , low
loss cable . Resistive at tenuators can be used to m ini m ize
reflect ions if the applied signal has suitable am pli tude .
Select a P - P VOLTS setting appropriat e to the am pli tude
of the signal being m easured . The P - P VOLTS figure on the
front panel indicat es the m ini m um signal am pli tude which
will produce a count . The best P - P VOLTS setting is one
that is m uch larger than the largest noise signal anticipat ed ,
A
2-5

Operat ing Instruct ions - 7014 ( SN B050000 & up )
but where the
signal is
sufficient ly
larger
than the P - P
VOLTS
setting to
ensure a
steady
count .
Generally ,
begin
wit h the largest P - P VOLTS setting . Then decrease the
switch
setting
if
necessary
to
obt ain
a
steady count
.
Thi s is the poi nt
on the positive
- going slope
select ed for
triggering
when the
PRESET
pushbutton is
pressed , and
is
the condition
represent ed
in Fig
. 2-3A and
B.
Noise pulses or
ot her signal
com ponents m ay
be pre
sent ed
which are
of
sufficient
am pli tude
to
produce
un
wanted
trigger
pulses .
A typical
condition is
represent ed
in
Fig .
2-4A . The
result ing
trigger
pulses
shown in
Fig .
2-4B
will
cause an
errat i c or
incorrect
count .
The COUPLING switch det erm ines the coupling be
tween the CH A INPUT connect or and the trigger circuit .
Generally , use AC coupling to block the DC com ponent of
a signal . Ot herwise , the DC com ponent m ight cause the
signal level to be beyond the range of the LEVEL / SLOPE
control . DC coupling can be used for low - frequency signals ,
or for pulses wit h known DC levels . See Table 1-1 in the
Speci fication sect ion for the frequency range and am pli tude
li m it s for each coupling m ethod . The COUPLING switch
does not affect signals select ed via the TRIG SOURCE posi
tion of the INPUT SENS switch .
Pressing
the
VAR
pushbutton
enables
the
LEVEL
/
SLOPE control to be used to m ove the hysteresis above or
below the O - volt level . The condition represent ed in Fig .
2-4A and B can
be
correct ed by using
the
LEVEL
/
SLOPE
control to m ove
the hysteresis to
a level above or
below the
The BW
switch
provides
a
m eans of
filt ering out
hi gh
frequency noise pulses
which m ay cause
errat i c
readings
.
Generally , use the 5 MHz setting unless the signal to be
count ed is above this frequency . The BW switch affect s
signals connect ed through bot h the int ernal TRIG SOURCE
and the
CHA
INPUT
connect or
. OV
.e2
-e
1
( A )
1
The trigger circuit has a hysteresis ( basic sensit ivit y ) of
approxi m at ely
100
m illivolt s . A typical
signal
waveform at
the input to
the trigger
is shown in Fig
. 2-3A . The
hysteresis of the trigger is represent ed by the shaded area .
Each t im e the signal level ( including DC level ) rises above
the upper
hysteresis li m it
ez , and falls
below the
lower
hysteresis li m it e , the trigger circuit produces a rectangular
waveform as shown in Fig . 2-3B . Thi s rectangular waveform
is the signal act ually count ed by the count ing circuits .
( B )
Fig . 2-4 . ( A ) Input signal wit h noise in PRESET hysteresis level ; and
( B )
result ant trigger
output .
Generally , the best poi nt on a waveform for triggering
the count er is where the slope is steep , and therefore
usually free of noise Assum ing a sine - wave signal wave
form , the steepest slope occurs at the zero - crossing poi nt .
OV
e2
OV
.
e
1
( A )
( A )
M
e2-01
100 m V
( B )
(
B )
Fig . 2-3 . ( A )
Signal input to
trigger ; shaded
area
represent s trigger
hysteresis wit h
PRESET
butt on
depressed . ( B )
Trigger output .
Fig . 2-5 . ( A )
Signal input to
trigger ; shaded
area
represent s
hysteresis
set
above
noise
pulses
. (
B )
Resultant
Trigger
output
.
2-6
 

Operat ing
Instruct ions 
7D14 (
SN
B050000 & up
)
the
tot al count at
the end
of the
gat e
t im e
or
to
display
each count as it
is m ade . Also ,
the 7D 14 can add
the count s
m ade during successive gat e t im es . ( For further inf orm a
tion , see
Tot alize
under
Measurem ent
Modes
. )
( A )
(

An
ext ernal
gat ing
signal can be
used to
control
the
gat e
t im e or
m easurem ent
int erval
. The
gat ing signal is
con
nected
to
the EXT
GATE
connect or
and
is
select ed by
pressing the
MANUAL
GATE OFF
pushbutton
. See
the
Speci fication
sect ion for
ext ernal gat e signal
requirem ent s .
( B )
REF
FREQ / CH B
controls
. The INT
1 MHz
pushbutton
select s the int ernal cryst al oscillator for use as a reference
signal for frequency m easurem ent s . The one m egahert z
signal is available at the front - panel EXT IN / MONITOR
connect or when the INT 1 MHz butt on is pressed in .
Fig . 2-6 . ( A ) Signal input to trigger ; shaded area represent s hysteresis
set above noise pulses ; ( B ) Trigger output wit h LEVEL / SLOPE con
trol set in
negat ive
- slope regi on
.
noise . Fig . 2-5A shows the signal wit h the hysteresis m oved
above the noise wit h the correct ed trigger output shown in
B. Fig . 2-6A and B shows the sam e waveform s as in Fig .
2-5 , only wit h the LEVEL / SLOPE control set in the nega
tive slope regi on . Note that the trigger pulse shown in Fig .
2-6B goes positive when the signal input goes negat ive .
When greater accuracy is required than is provided by
the int ernal cryst al oscillator , a one m egahert z ext ernal
t im i ng
standard
can be connect ed to the EXT IN /
MONITOR
connect or
.
Pressing the EXT IN
pushbutton
select s the signal connect ed to the EXT IN connect or .
Measurem ent Interval Controls . The MEASUREMENT
INTERVAL switch select s the t im e int erval ( also called gat e
t im e ) during which the 7D14 count s . The source of the
pulses which control the t im e int erval det erm ines the
m easurem ent
m ode
.
The EXT IN connect or and pushbutton are also used for
m ak ing rat io m easurem ent s . The 7D14 will com pare the
frequency of the signal connect ed to the EXT IN connect or
to the frequency of the Channel A signal . ( For further
inf orm at ion , see Rat io Measurem ent s under Measurem ent
Modes . )
The int ernal gat e circuits derive gat e t im es from a one
m egahert z reference frequency signal to m ak e frequency
m easurem ent s . The gat e t im es thus derived are select ed by
the 1 m s , 10 m s , 100 m s , 1 s , and 10 s pushbuttons . The
m easurem ent int erval select ed det erm ines the m easurem ent
range and resolut ion . These pushbuttons also aut om at ically
select the m easurem ent unit s and decim al position in the
display . Table 2-2 gives the frequency range and resolut ion
for each t im e int erval , and shows the display decim al posi
tion and m easurem ent unit s .
Display Tim e Controls . The DISPLAY TIME control is
used to set
the lengt h
of t im e a
m easurem ent
is
displayed
before the
next
m easurem ent is started .
The display
t im e
can be varied from at least 0.1 second to five seconds or
longer .
The ( infinite ) detent position of the DISPLAY TIME
control
sets
the 7D14
to
display the last
m easurem ent
indefinitely
,
or unt il
reset by the
RESET pushbutton or an
ext ernal signal .
Generally , use the short er m easurem ent int ervals for
hi gh -
frequency , low -
resolut ion
m easurem ent s and the
longer
int ervals for m easurem ent s requiring hi gh resolut ion .
The display t im e circuit is locked to the 1 m s through 10s
MEASUREMENT INTERVAL pushbuttons so that the tot al
display t im e is the sum of the DISPLAY TIME control set
ting and the m easurem ent int erval select ed .
Tot alizing , or count ing a num ber of event s , is accom
plished by
count ing during
a t im e
select ed by the
MANUAL GATE ON / OFF pushbuttons . The gat e t im e is
started by pressing the MANUAL GATE ON pushbutton ,
and
stopped
by
pressing
the
OFF butt on .
The m anual m ode
is generally used to count a num ber of event s for a rela
tively long , indefinite t im e . The 7D14 can be set to display
When used wit h m anual gat e operation , the DISPLAY
TIME
control
det erm ines when to
tot alize
the
count s m ade
during separat e gat e int ervals ( for further inf orm at ion , see
Tot alize under
Measurem ent
Modes
) .
A
2-7

Operat ing
Instruct ions

7D14
(
SN
B050000
&
up )
MEASUREMENT
MODES
Introduct ion
Connect
the
ext ernal
signal
to
the
REF
FREQ /
CH B
EXT
IN
connect or
and
press
the
EXT
IN
pushbutton
.
The
function
of
the
MEASUREMENT
INTERVAL
1
m s 
10
s
pushbuttons
is
the
sam e as
when
using
the
int ernal
t im e
base oscillator
.
The
7D
14
has
three
prim ary
m easurem ent
m odes
:
fre
quency
,
rat io
,
and
tot alize
(
num ber
of
event s ) .
The
following
discussion
gives
general
inf orm at ion
about
each
m ode
and
instructions
on
m ak ing
the
m easurem ent s
.
Rat io
Measurem ent s
Frequency
Measurem ent s
The
7D14
provides
direct
m easurem ent of the
average
frequency
of
signals
up to
525
MHz .
The
input
to
the
count ing
circuits
is
select ed
by
the
INPUT
SENS / P -
P
VOLTS
control
from
eit her
the
signal
connect ed
to
the
CH
A
INPUT
connect or
or the
int ernal
trigger
pickoff
signal
from
the
Indicat or
Oscilloscope
trigger
circuits
. (
TRIG
SOURCE
; see
Count ing
a
Displayed
Signal
) .
Rat io
m easurem ent s
com pare
the
frequencies of
two
signals .
Norm ally
,
the
hi gher
frequency
signal
is
applied to
Channel
A (
via
CH
A
INPUT
connect or or
int ernal
TRIG
SOURCE
)
and
the
lower
frequency
signal
is
applied
to
Channel
B (
via
EXT IN
connect or
wit h
the REF
FREQ
/
CH
B
EXT IN
pushbutton
pressed
) .
The
MEASUREMENT
INTERVAL
1
m s
through
10
s
pushbuttons
select
the
count ing
t im e as
derived
from
the signal
applied to
Channel
B.
The
7D14
then
count s
the
pulses
derived
from
the
Channel
A
signal
during a
t im e
int erval
est ablished by
the
Channel B
signal .
The
display
rat io
m easurem ent is
equal
to :
Frequency
Channel
A
x
106
x
Frequency
Channel B
MEASUREMENT
INTERVAL
The 7D14
count s
the
input
pulses
over an
int erval
select ed
by the
MEASUREMENT
INTERVAL
1 m s
through
10 s
pushbuttons
.
The
m easurem ent
int erval
select ed
det erm ines the
m easurem ent
range and
resolut ion
.
These
pushbuttons
also
aut om at ically
select the
m easure
m ent
unit s
and
decim al
poi nt
position
in the
display .
Table
2-2 gives
the
frequency
range
and
resolut ion
for
each
t im e
int erval
and
shows the
display
decim al
poi nt
position and
m easurem ent
unit s .
whose
denom inat or
is
known
to
be 1.
Thus
, a
rat io of
30.000
: 1 will
be
displayed
as
30.000 .
The decim al
poi nt in
a
rat io
m easurem ent
display
is
correct ly
positioned
only
when
using
the
1
m s ,
10
m s , or
100
m s
MEASUREMENT
INTERVAL
pushbuttons .
Readings
obt ained
when
the 1 s
or 10
s
butt ons
are pressed
m ust be
m ult iplied
by
10 to
correct
the
decim al
position
.
Generally ,
use the
short er
m easurem ent
int ervals
for
hi gh -
frequency ,
low -
resolut ion
m easurem ent s
and the
longer
int ervals
for
m easurem ent s
requiring
hi gh resolut ion
.
Rat io
m easurem ent s are
di m ensi onless ( i.e.
, no
m easure
m ent
unit s
) ;
however ,
the
MHz or
kHz legend
will
rem ai n
displayed
Greater
Accuracy
. For
greater
accuracy
and
/ or
stability
when
m easuring
frequency , an
ext ernal
1
MHz cryst al
signal
can
be
substit uted
for
the
int ernal
t im e -
base
oscillator
.
The
ext ernal
signal
m ust have
greater
accuracy
than the
int ernal
oscillator
( see
Speci fication
sect ion ) and
have
a
m ini m um
am pli tude
of 0.8
volt peak
- to -
peak .
Tot alize (
Count
Num ber of
Events
)
TABLE 2-2
Introduct ion
.
The
7D14
will
count
the
num ber
of
pulses
applied to
Channel
A (
via the
CH A
INPUT
connec
tor or
TRIG
SOURCE
) up
to
99,999,999
pulses at
a
rat e
not
to
exceed
525
m egahert z
.
The
pulses
will be
count ed
during
a
t im e
int erval
(
gat e
t im e )
det erm ined
eit her
by
the
MANUAL
GATE
ON
/ OFF
pushbuttons or
by a
gat ing
signal
connect ed
to
the
EXT
GATE
input
connect or .
Over
ranging
(
count
exceeding
99,999,999
) is
indicat ed
by a
" greater
than "
sym bol
>
)
preceding
the digital
readout
.
MEASUREMENT
INTERVAL
DATA
MEASUREMENT
INTERVAL
UNITS
RESOLUTION
MAXIMUM
FREQUENCY
1
m s
MHz
1 kHz
100
Hz
MHz
10
m s
100 m s
MHz
10 Hz
525.000 MHZ
525.0000 MHZ
525.00000
MHz
99999.999
kHz
9999.9999
kHz ?
Display
Storage
Modes
.
Two
m odes
of
displaying
the
count
can be
select ed
when
using
MANUAL
or
EXT
GATE
operation
.
These
m odes
are
select ed
by
the
Man
Gate
Stor
age
switch
.
1
s
1 Hz
kHz
kHz
10 s
0.1 Hz
1 of the m axi m um frequency is exceeded , a " greater than " sym bol
( > ) will
precede the
readout
display .
With the Man
Gate
Storage switch ON
, the tot al
count
is displayed
at
the end
of the
gat e or
count int erval
.
2-8
A

Operat ing
Instruct ions -
7014 (
SN
B050000 &
up )
6. Set the INPUT SENS / P - P VOLTS , COUPLING , BW ,
and
TRIGGER
LEVEL
/
SLOPE
controls
as
necessary to
obt ain a
steady count .
Thi s is the
m ode
norm ally used for
EXT GATE
applicat i ons
when count ing a num ber of event s wit hin short , repetit ious
gat e t im es . The advantage of using the storage ON m ode is
that no display flicker is observed during the count cycle .
The last m easurem ent taken rem ai ns displayed unt il the
next m easurem ent has been com pleted and is ready to be
displayed . Thi s is the sam e m ode used when m ak ing fre
quency m easurem ent s wit h the gat e t im e det erm ined by the
1 m s through 10 s pushbuttons .
7. Set the DISPLAY TIME control to  ( fully clock
wise ) .
8. Depress the MANUAL GATE ON pushbutton and
the count er will start count ing . If necessary , press the
RESET pushbutton so that the count will start from zero .
In the storage OFF m ode , each count is displayed as it
occurs ; thus , the display always indicat es the tot al count at
that t im e . Thi s m ode is norm ally used wit h MANUAL
GATE operation when count ing a num ber of event s over a
relat ively long , indefinite t im e . A typical applicat i on would
be count ing it em s passing a transducer on an assem bly line .
9. To t erm inat e the count , depress the OFF butt on .
Using the External Gate . To m ak e a count m easurem ent
using an
ext ernal
gat ing signal ,
proceed as
follows :
Display Tim e . In the usual applicat i on ( MANUAL
GATE operation only ) , in which pulses are count ed over
one int erval only , the DISPLAY TIME control functions in
its usual m anner ; i.e. , the display will be reset to zero aft er
the display t im e has elapsed . However , if it is desired to add
one int erval to the next ( tot alize the count ) , the DISPLAY
TIME control should be set to  . The sam e effect will be
obt ained whenever anot her gat e int erval is init iat ed before
the display t im e has elapsed .
1. Set the int ernal Man Gate Storage switch for the de
sired m ode . ( The ON position is usually used for short gat e
int ervals . )
2. Install
the 7D 14 in
any
available plug - in
com partm ent
of a
Tekt ronix 7000 -
series
oscilloscope .
3. Turn the oscilloscope power on . Allow about 20 m in
utes
warm up .
In EXT GATE applicat i ons , where the gat e t im es are
repetit ious , the ext ernal gat ing signal is locked to the dis
play t im er
circuitry . Thus , aft er
one m easurem ent
has been
taken ,
anot her gat e
int erval will not
be init iat ed unt il
the
com pletion of
eit her the
display t im e
or the gat e "
off "
t im e , whichever is longer . In this way , one int erval is not
added
to
anot her
.
4. Advance the oscilloscope Readout control to obt ain a
usable
readout
display
.
Using the MANUAL GATE . To m ak e a count m easure
m ent using the MANUAL GATE ON / OFF pushbuttons ,
proceed
as
follows :
5. Connect the input signal to the CH A INPUT
connect or .
1. Set the
int ernal MAN
GATE
STORAGE switch
for
the desired m ode
. ( The OFF position
is usually
used for
long gat e
int ervals
. )
6. Connect the ext ernal gat ing signal to the EXT GATE
input connect or through the BSM to BNC m ale adapter
( supplied accessory ) . The ext ernal gat ing signal m ust m eet
the input requirem ent s as given in Sect ion 1 of this m anual .
2. Install the 7D 14 in any available plug - in com part
m ent of the Tekt ronix 7000 - series oscilloscope .
7.
Set the 7D
14
TRIGGER
controls as
necessary to
obt ain a
steady
count .
3. Turn the oscilloscope power on . Allow about 20
m inut es
warm up
.
The
ext ernal gat e
function can be used in
conjunction
wit h a delayed sweep to count the quantit y of pulses wit hin
a burst . The 7D14 ext ernal gat e input is driven by the
delayed - sweep gat e output to count the num ber of pulses
wit hin the delayed - sweep t im e ( int ensified zone ) . To use
this function
,
proceed
as
follows :
4. Advance
the oscilloscope
Readout
control to
obt ain
a
usable
readout
display
.
5. Connect
the input signal
to the
CH A INPUT
connect or .
1. Set the int ernal Man Gate Storage switch for the de
sired m ode . (
The ON
position
is usually
used for short
gat e
int ervals . )
A
2-9

1
Operat ing
Instruct ions
- 7D 14
( SN B050000
& up )
R
2010
1V
500S
signal is
rout ed to the
7D14
from
the
am pli fier unit
trigger
pickoff
through the
oscilloscope
trigger
source select ion
circuitry
. Thi s
necessitat es
operat ing
the 7D
14 in one
of the
horizontal
com partm ent s
of an
oscilloscope which
can
accom m odat e four plug - in unit s .
1
ik
The INPUT SENS / P - P VOLTS switch select s the signal
from the
am pli fier unit
when it
is set to TRIG
SOURCE .
The Trigger Source switch for the horizontal com partm ent
containing
the
7D 14
m ust be
set to
select the
vert ical
com
part m ent
originat ing
the
signal to
be
count ed . In
addit ion
,
dual - trace am pli fier unit s contain further trigger source
select ion . Thi s m ust be set to select the correct channel .
Signals
select ed in
the
TRIG SOURCE
position
are AC
coupled which li m it s the low - frequency response . The hi gh
frequency
response
is li m it ed
by
the
bandwidth
of the
am pli fier
unit being
used
.
Fig . 2-7
. Count ing
the
num ber
of pulses
wit hin
a burst
.
2.
Install the
7D 14
in a
vert ical
plug
- in
com partm ent .
3. Connect the input signal to the CH A INPUT and
am pli fier unit input connect ors via a BNCT connect or and
short
BNC
cable
.
Thi s m ode of operation is m ore convenient for sim ul
taneous m easurem ent s than using separat e probes for
count er and oscilloscope . Also , one signal connect ion places
less load on the circuit under test than if separat e probes
were used . An added advantage is being able to use the
am pli fier unit
to
am pli fy signals whose
am pli tude
would
ot herwise be insufficient to trigger the 7D14 .
4.
Connect the
delayed
gat e
output
to the
EXT
GATE
connect or through a BSM to
BNC m ale
adapter (
supplied
accessory
) .
5.
Press
the
MANUAL
GATE
OFF
pushbutton .
6. Turn the oscilloscope power on . Allow about 20 m in
utes
warm up
.
Trigger
Indicat or
The output of the 7D14 trigger circuit can be displayed
on the CRT , along wit h the signal being count ed . The 7D14
controls can then be adjusted while observing the CRT dis
play for
triggering at the
desired
poi nt
on the
waveform .
7. Advance the oscilloscope Readout and Intensit y con
trols as
necessary to
obt ain
a
usable
display .
8. Set the delaying t im e - base unit Tim e / Div control to
view several cycles of the input - signal waveform as shown in
Fig
.
2-7
.
To use this m ode of operation , the 7D14 m ust be
operated in a vert ical plug - in com partm ent . The signal to be
m easured is connect ed to the CH A INPUT connect or and
to the input of the ot her vert ical unit using a T connect or .
The two waveform s can then be displayed by setting the
oscilloscope Vert ical Mode to Alt or Chop .
9. Set the delaying t im e - base unit Delay Tim e Mult and
the delayed t im e - base Variable Tim e / Div controls to int en
sify the pulses to be count ed ( see Fig . 2-7 ) .
10. Set
the 7D 14
TRIGGER
controls as
necessary
to
obt ain
a
steady count .
The " Trigger Indicat or " is a rectangular waveform dis
play wit h a nom inal am pli tude of 0.2 division peak - to - peak .
Proper triggering is indicat ed when the  Trigger Indicat or "
waveform
m at ches the
signal
waveform
frequency and
duty
cycle as shown in Fig . 2-8 .
OPERATING MODES
Count ing a Displayed Signal
Thi s m ode of operation enables sim ult aneous count ing
and CRT display of a signal . The CRT display is obt ained in
the usual m anner ; i.e. , the signal is connect ed to an am pli
fier unit in a vert ical plug - in com partm ent and a t im e - base
unit in a horizontal com partm ent provides the sweep . The
The
Trigger
Indicat or
display
vert ical
position is set to
the CRT
center
at
the
factory .
However , the
display
can be
positioned for the convenience of the operator wit h the
int ernal
Display
Pos
adjust m ent R866 (
see Fig . 2-2
) . To
m ak e this
adjust m ent
,
use the
following
procedure
:
a
1.
Rem ove the
Indicat or
Oscilloscope left
cover and
the
7D 14
left side
shield
.
2-10
A