Tektronix 7704A User Manual

Circuit Description -7704A
Service
Α Sweep
L
oc
k
out
. Th e Α Sweep L
oc
k out stage
produces an output
level at t h e collector of Q2577 t h at
d
etermines if t he Α H O R IZ time-base unit can p ro duce α
sweep . If t h is ou t p u t is ΗΙ , t he Α ΝΟ R ΙΖ unit is loc k ed out
( d isabled) so it cannot p roduce α sweep . If t he level is LO,
t h e Α ΗΟ R ΙΖ u nit is enable d and can produce α sweep
w h en triggere d .
As s h own b y t h
e
logic d
iagram and input/output table of
F ig . 2-5, only two
combinations of input con d itions
pro duce an
Α
Sweep
L
oc
kout level
(H
I) ; if any one of t he
p rescribe d conditions is
not met, t h e Α Sweep L oc kout
level is L O an d t h e
Α
HO
R ΙΖ time-base unit is ena b le d .
χ - γ

ΙΑ
H oriz)
~
Com pe n satio n
( Β H oriz) Ε
Delay M o d e Co n trol O
u t
2-10
A LT M od e ( ho
r iz)
MFC h an n el
Switc h
Sig n al (Dis p lay Β )
6
Α Gate

2
< -L
Β H ol d off ~
Φ = H as no effect in
t h is case .
Inp u t
T h e first combination
d isa b les t h e Α sweep w h ile t he Β
swee
p
is
being d is p layed in t h e A L T h orizontal mo d e (bot h
units must be
.
i n time- b ase mode) if non-delayed operation
is being u sed . T h e second com b ination d isables t h e Α sweep
d
uring d elaye d -sweep operation so t h at t he Β sweep can
complete its h ol d off before t h e next Α sweep begins .
Β Sweep Lockout .
T
h
e Β Sweep L
oc
kout stage p ro d uces
an output level at t
h e collector of Q2579 t h at determines
if
t
h
e
Β H O R IZ time- b ase unit can pro d uce α
sweep . Α HI
outpu t level loc k s out (in h ibits) t
he Β ΝΟ R ΙΖ unit an d α
L O level enables t h e Β
H O R ΙΖ unit
to
produce α sweep .
U 2573 Ο 3
02577
O
u t pu t
F ig . 2-5 . ( Α ) L ogic d iagra m for Α Sweep
L
oc
k o u t stage ;
(
Β
)
Table of i np ut/o u tp u t com b i n atio n s .
Α Sweep
L
oc k o
u t
1 2 4 5 12 13
16
HI
Φ HI
HI L O HI
HI
Φ
L O
Φ
Φ HI HI
Φ HI
All ot h er combinations
L O

Tektronix 7704A Specifications

General

Brand	Tektronix
Model	7704A
Category	Test Equipment
Language	English