Tektronix 2213 Service Manual

T h eory of O p eratio n -2213 Service
In t
h e following overall f u nctional d escri
p
tion
of
t
he
2213 Oscillosco
p e, refe r to t h e basic block d iagram
( F ig-
ure 3-1) an
d to t h e d etaile d b loc k diagram
( F igure 9-4)
locate
d in t he "Diagrams" section of
t h is man u al . In
F igures 3-1 a nd 9-4, t he num b
ere d d iamon d symbol in
eac h ma j or block refers to t
h
e appr
o p riate sc h ematic
d iagram num b er .
Signals
to be d is played on t h e crt
are
applie
d to eit h er
t
he
C
H 1 O R Χ in put connector or t
h
e C
H 2
O
R Υ i nput
connector
. T h e signals may be cou p led to
t he atte nu ator
circuit
eit h er d irectly (DC) or t h roug h an i
n put-cou p ling
cap acitor (AC) .
T he input may also be discon
n
ecte
d and
t he input
to t he attenuators grounde d w
h
en
t he GN
D
p osition
of t he cou p ling switch is use
d .
In
t he GND
p osition,
t h e ac-cou p ling cap acitor is allowe
d to p rec h arge
to t
h
e do
level p resent at t he input con
n
ector
.
T
h is p re-
c
h arging p revents large trace s h ifts of t h
e
d is
p
lay
w hen
switc
h ing from GND to AC co u pling .
Each c
hannel out put signal f r om t he Atten uator cir-
cuitry is a pp
lied to t he V ertical P ream p lifier circ
u
itry
for
furt
h er amplification . T h e C hannel 2 P reamplifier
i n clu d es
an
Invert feature t h at allows t
h
e op
erator to invert t he
C
h annel 2 signal d is p lay on t
he cat hod e-ray tube (crt) .
Trigger P ic koff Am
p lifiers in each chann el supply an
internal
trigger signal from eit her chann el signal or
from
b ot h c h
annels
to
t he Internal Trigger Am p lifier in t
he
Trigger circuitry
.
Each c hannel signal is selecte
d for display in turn by t he
C h annel Switc h ing L ogic
circuit under control of t he
front- p anel VER TICA L M OD
E switch es . T h e out put signal
from t h e C h annel Switc
h
ing L
ogic circuit is app lie d to α
Dio de Gate circuit . T
h
e Diode
Gate circuit switch es eit h er
c hannel signal (or bot
h signals for ADD) to α Delay L ine
Driver stage t h at su pp lies t
h e p ro p er drive an d im p ed a nce
matc h to t he Delay L ine . T h e
Delay
L
ine prod uces ap p r ox-
imately 100 ns of delay in t h e vertical
signal to allow the
H
orizontal circuitry time to p ro d uce t
he necessary swee p
to d is p lay t
he signal .
F
inal am
p lification of t he vertical signal is s up plie db y
t h e V ertical
Out put Am p lifier . T h e V ertical
Out put
Am p lifier su p
plies th e re qu ire d signal levels necessary
to
p ro d uce vertical
d eflection of t he electron beam in t h e crt
.
T
he Trigger circ u itry u ses eit h e r t
h
e
Internal Trigger
signal d erive d from t
h e input signal(s), an E xternal Trigger
3- 2
G
ENER A L D E SC R I P
TIO N
signal, or α L ine Trigger
sig n
al
o btain e d from t h e ac-p ower-
source in put waveform to
develop t h e triggering signal for
t he Swee p Generator
.
An
Auto Trigger circ u it ensures t
h
at
t h e range of
t h e T RIGG ER LEVEL control conforms
app
roximately to t h e peak -to- peak am p litu de of t h
e trigger
signal w h
en
eit
h er
A
U TO or T V F I EL D T R IGG ER MOD
E
is selecte
d .
In
N O RM M OD E , t h e T R IGG
ER LEVEL
control must
b e a d j usted for t he cor r ect trigger
signal level
before α swee p can
be generated .
Α T V F iel d sync
circuit p rovi d es stable triggering on
televisio n -signal
vertical-sync pulses . Triggering at t
he
television line
rate is accomplis hed w hen eit h er AUTO
or
N O RM M OD
E is use d .
T h e
Sweep
L
ogic circuit controls t h e generatio n of t
h
e
swee p and t he
unblan k ing of t he Ζ -Axis Amplifier for t
h
e
Swee p d is p lay .
Wh en t he T RIGG ER MOD E switc
h
is
set to eit
h er
A
UTO or T V F I EL D and no trigger
signal is
p resent, t he Auto Baseline circuit causes
t h e Swee p Logic
circuit to prod uce α s w
eep
after
α
p
erio d of time . In t he
N O RM p osition of t
h e
T R
IGG ER M OD E switc h t h e
Auto B aseline circuit is d
isable d , and α swee p will not be
generated
until
α
triggering signal is received .
T h e out p u t gate signal
from t h e Swee p Logic circ u it is
app lie d to t h e M iller Swee
p circuit . T h is circuit p ro d uces
α linear sweep out p ut
with α
run-up
time t h at is controlled
by t h e S
E
C/DI
V switch . T he sweep signal is ap plie d
to
t
h
e
H orizontal P ream p lifier for initial amplification
. F inal
am
p
lification of t h e swee p signal to d rive t h e crt h orizontal
d eflection plates is provid e d by t
h e H orizontal Out put
Am p lifier .
T he H orizo n tal P
reamplifier gain is increased by α factor
of 10 w h en t h e Χ 10 M agnifier
feature is used . H orizontal
positioning of t he d isplay is also accom
p lis hed in t he
H orizontal Pr eam p lifier circ u it .
In t h e Χ - Υ M ode of
op eration the C H 1 signal, via t h e
internal Trigger circuitry, is a p
plie d to t he ΧΥ Amplifier
w h ere it is am p lifie d
for a pp lication to t he H orizontal
P ream p lifier . In t h is o p
erating mode, t he CH 1 I n ter n al
Trigger signal supp lies t
he horizo n tal d eflectio n to t he crt,
and ' α sweep signal is
not p roduce d b y t he M iller Swee p
circu it .
T h e H O R IZO N TA L M OD
E switch (
ΝΟ
D L Y, I NT EN S,
and DL Y'D)
controls t he action of t h e Delay circuit . T h is

Tektronix 2213 Specifications

General

Brand	Tektronix
Model	2213
Category	Test Equipment
Language	English