DC
502
CONTROLS AND CONNECTORS
MHZ
and
kHz Units
Indicators
LED indicates that readout
displayed
number should
be multiplied by 106
(MHz) or
103 (kHz).
Gate
Indicator
Display
Readout
LED
readout, seven 7-
segment
digits
with auto
matically
placed decimal
point.
The leading zeroes
are
suppressed unless an
overflow is indicated.
Overflow
Indicator
LED indicates
overflow
off
leading
digits when readout
attempts
to display more
than
seven
digits.
DISPLAY
Time
Control
Variable
control
concentric
with MEASUREMENT
IN
TERVAL
switch sets the,
length
of time the reading
will be
displayed
after the
count is made and before
the next measurement
is
taken. Display time
can be
varied
from 0.1
second
(MIN) to
about
10
seconds.
HOLD position
(clockwise)
provides con
tinuous
display
until reset
by
pressing
the RESET
button.
÷
10
pre
-
scale
input
Connector
Lights during
the active
gating
interval.
RESET
Pushbutton
Manual Gate Pushbutton
ATTEN
Pushbuttons
MEASUREMENT
INTERVAL
Switch
Two buttons select X1,
X5, X10,
or X50 attenua
tion
of
the input signal.
Selects
one
of four
gate
times
from the
internal
time-base
clock (10 s, 1s,
.1
s,
,01s), or selects
MANual
gate, for either
the DIRECT INPUT
or the
÷10
PRE-SCALE
INPUT.
Manually resets the
counter
to zero, initiates a
new
count
when not in
manual-gate mode, and
provides a segment check
of
the
7 readout digits.
Operable
when MANual is
selected
by the
MEASUREMENT
INTER
VAL
switch.
Button in
starts
the measurement
interval gate; button
out
terminates the gate.
DIRECT
INPUT
Connector
BNC connector for signal
inputs
to pre-scaling cir
cuitry.
TRIGGER
LEVEL
Control
BNC
connector for signal
inputs to the attenuators
and direct-counting cir
cuitry.
Selects
the
amplitude point
on the
DIRECT
INPUT
signal
at
which
the
trigger
ing window
is
placed.
3-9
Summary of Contents for DC 502
Page 4: ...DC 502...
Page 24: ...39 39 Relocated on back of board SN B070000 REV MAY 1974...
Page 33: ...FIG 1 EXPLODED...