Tektronix 570, Руководство пользователя

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9 , 6
TYPE 570 CHARACTERISTIC-CURVE TRACER
C ATHOD£. RAY· TU BE DISPLAY
Vertical
Axis-Concentric
c
o n t
r
o l
s
provide for se­
lection of
plate,
screen,
or
grid current display;
and se­
l e c
t
io n of anyone
of eleven current-per-division v
a
l ues
-0.02, 0.05, 0.1, 0.2,
0.5, 1, 2, 5, ) 0, 20, and
50
ma/div. A
graticule
divides the
screen into
ten
ve
rtic al
divisions.
Ca
l
ibr
a
t i
o
n
accuracy is within
3"10, p
e
r
m
i t
t
i
ng
accurate current readings directly from the
screen.
DISPLAY
l()
V�Rn<:At
MAjOW
�u·.a
�
HOlll20NTAt
.
,' YOllS/D,,,
1
?:
POSITIONING
HO�I1.0Nl�l
Horiz:ontul Axis-Either
p l a t e or grid voltage can
be
displayed on
the
horizontal axis,
and nine voltage·
per-division
values
are
available-O.l, 0.2, 0.5, 1, 2, 5,
10,20, and
50
v/div.
Ten
horizontal
divisions are scrib­
ed
on
the
graticule. Calibration
accuracy is within
3"10,
permitting
a
c c u
r
a
t
e
voltage readings
directly from
the
screen.
Positioning-Concentric controls provide
for both
vertical and horizontal
p
o s
i
t
i
o
n
i
n g
of
the
display.
GRID-STEP GENERATOR
Family of Curves-A
variable control is provided
to
adjust
the
number
of
curves in
the
display.
As
few
as
four and
as
many
as
twelve
curves can
be
selected.
A
single family can be
safely
displayed with the tube
un·
der heavy overload conditions by
means
of
a position
on
the STEPS/FAMILY
control and
a
push
button. With
the
STEPS / F AM il Y
control in the single-family position,
pressing the button applies the selected conditions to
the tube for
only
a
fraction of
sec o nd .
Use
of
the SING L E
FAMilY
push
button permits
observation
or
photography
of
tube characteristics under
unusual
conditions without
d
a
n
ge
r
of
damage
to the tube under
test.
The
STEPS/SEC
switch
controls
the switching-rate of
the
step generator.
A 120
or
240-steps/sec
rate
c
a
n
be
selected.
The extra
120-steps/sec
position causes switch­
ing to
occur
at the opposite end of the characteristic
.� :.;�
V{)� ;'),':':.Hr->
10
curve,
for
convenience
when
the
area
of
interest is
01
ei t
h
e r end
of
the curves displayed.
Bias voltage
applied to the
grid of
t h
e
tube
under
test
is impressed in
a
series of
steps to
produce
the number of
curves desired in
the display. The
voltage difference
be­
tween steps
is
selected by
a
seven -position switch. Cali­
brated switch positions are: 0.1,
0.2, 0.5, 1, 2,
5, and
10
volts/step,
a
cc
u
r
a
t
e within
3
"I.. Up to 1
50 ma peak
grid
current is available. A
variable control
is
provided
to adjust the starting
p
o
i n t
to
a
positive
v
o
l
t
a
g
e
,
zero, or
a negative voltage. Pressing
the ZERO BIAS
push b
u
t t o n
causes
the display of
the zero-bias curve
only,
to use
os
a reference
in
adjusting the s
t
a
r
t i
n
g
point.
As many
as
eight positive-bias curves
can be
included in the
display.
PLATE-SWEEP GENERATOR
An
eleven-position
switch
selects
the
desired
series­
load resistance for the plate circuit of the tube under test.
Series-load values are:
300 oh
ms,
1
k, 2 k, 5 k, 10 k,
20 k, 50 k,
1
0
0 k, 200 k, 500
k, and 1
megohm. Power­
handling capacity of all load resistors is sufficient to
dis­
si
p
at
e
the maximum
power
a v
a i
l
a
b l
e in the plate circuit.
The
peak voltage applied
to
the plate through the
s e r i es -l oad resistance is selected
by
an eight-position
switch. Peak v
o
l t a g
e s
are: 5,10,20,50,100,200,300,
and
500
volts.
OPERATING VOLT AGES
Heater voltage
is
available
in 17 fixed steps: 1.25,
1.4, 2.0, 2.35, 2.5, 3.15, 4.2, 4.7, 5.0, 6.3, 7.5, 12.6,
18.9, 25, 35, 50, and
117
volts
ac.
A control permits
adjusting the selected
healer
yoltag-e
approximately
± 20"lo
for
s
i
m u
l
a
t
i
n
g
the effects
of
low
or high
line
voltage.
The
variable control provides sufficient
spread
Tektronix,
'ne.
3/56