TM
11-6625-539-15-2
OPERATING INSTRUCTIONS
Function
Control of indicator
3-1. General
Meter
Provides
readings
in
beta
ohms,
ICO
_____________
in
microamperes,
and
GM i n
The test set is designed so that it is a safe instru-
micromhos
as
required
to
test
ment to use with semiconductor circuitry. The volt-
semiconductor
devices
and
BAT
age and current levels that the test set can supply to
range
to
check
condition
of
internal
batteries.
any device are controlled so that the accidental mis-
Transistor
socket
____
For
use
in
conjunction
with
short
placing of leads will not damage any semiconductor;
lead
out-of-circuit
transistors.
however, to achieve valid readings, proper operation
Transistors
may
be
plugged
into
and switch setting are required. Controls and indi-
socket
directly.
cators, with the function of each, are listed in para-
3-4. Operating Procedures
graph 3-3. Operating procedures are described in
a. General. Before operating the test set, check
the meter to see if the pointer falls on the meter 0. If
it does not, turn the meter adjust screw, either clock-
wise or counterclockwise, until the pointer is exactly
over the 0 mark on the left side of the meter scale.
Before operating the test set, check the meter to be
The meter is shipped with the polarity switch placed
sure that the pointer indicates exactly 0. If it does
in the OFF position. When the polarity switch is set
not, turn the adjusting screw on the front of the
to OFF, all of the batteries of the tester are discon-
meter until the pointer is zeroed. The polarity switch
nected from the circuitry and a short circuit is placed
should be set to OFF.
across the meter. The polarity switch should be set to
OFF when the instrument is not being used.
3-3. Controls and Indicators
Caution: Never leave the polarity switch of the
instrument in one of the test positions when the
The controls for the test set are on the front panel;
instrument is not being used. Always return the
their functions are described in the chart below.
polarity switch to the OFF position to prevent
unnecessary drain of the internal batteries.
Control or Indicator
Function
b. Beta Measurement (Out-of-Circuit).
Polarity
switch
______
When
rotated
to
any
position
other
than
OFF,
selects
proper
voltage
(1) If a transistor with short leads is being
nnd
current
polarities
for
type
of
measured, place the transistor in the small socket on
semiconductor
device
being
tested
the lower right side of the front panel. The transistor
and for making reverse to forward
jacks on the front panel are spaced so that they will
ratio
tests.
accept a standard test adapter for rapid testing of
Fuction
switch
______
Selects
desired
function
to
be
tested.
CAL
control____________
a. W h e n
beta
is
being
measured,
sets
transistors with long leads.
(2) Plate the polarity switch to correspond to
collector current of transistor
under test to 1 ma.
the type of semiconductor device being used.
b. W h e n f i e l d e f f e c t t r a n s i s t o r s a r e
(3) Set the function switch to BETA CAL, and
being measured, sets gate to
adjust the CAL control for full-scale meter deflection.
source
voltage
at
100
mv.
c. When
forward
ratio
test
is
being
(4) Place the function switch to the BETA X1
made, sets diode current to
range, and read the BETA directly on the top
1 milliampere.
(BETA) scale of the meter. If the BETA is on the
Color-coded
jacks_____
Used
in
conjunction
with
color-coded
high portion of the BETA scale, advance the func-
plug-in
cables
to
make
connection
tion switch to the BETA X10 range and multiply the
from
test
set
to
semiconductor
reading by 10.
under test.
