Tektronix 2236, Instruction Manual

Page: 37 / 350

Operating Instructions— 2236 Service
CH 1 V— Measures dc voltage or true ac rms volt­
age signals applied to the CH 1 OR X & DMM verti­
cal input connector. For dc voltage measurements
set the Channel 1 Input Coupling switch to DCV
position, and for true ac rms voltage measure­
ments set the Channel 1 Input Coupling switch to
the AC RMSV position. There is no autoranging;
CH 1 VOLTS/DIV switch selects the range for the
CTM voltage measurements. The readout will indi­
cate the measuring mode the CTM is in by display­
ing an “Ac” or “dc” on the left side of the voltage
reading. In overrange condition the readout will dis­
play the word “OUCH”.
In CH 1 V mode, the CTM has the capability of
storing a relative reference value, such that the dis­
played value is the input voltage minus the stored
reference value. When either Channel 1 AC RMSV
or DCV volts are first entered, the stored reference
value is zero, and the Channel 1 input voltage is
displayed directly. To set the reference value,
press in the SGL SWP RESET button momen­
tarily, and the value on the readout becomes the
stored reference value. To regain normal voltage
measurement press again the SGL SWP RESET
button momentarily or change the CH 1
VOLTS/DIV switch position.
AC RMSV— Measures the true ac rms value of the
input signal applied to the Multimeter inputs, from
0 V to 349.9 V rms. The word "OUCH” is displayed
if 350 V or more is applied to the Multimeter input
connector.
TEMP— Measures temperature in degrees Celsius
°C when the TEMP button is pressed in, or de­
grees Fahrenheit °F when both TEMP and A TIME
buttons are pressed in. Temperature readings fol­
lowing by °C or °F are displayed on the CTM
readout.
<=3)))<50 (Continuity)— Press in both AC RMSV
and TEMP buttons for continuity measurements.
For resistance readings below 5.012 the word
“Short” is displayed and an audible tone will be
generated. For resistance readings greater than or
equal to 5.012, the word “OPEN” is displayed.
Self Test Routine— The CTM can be entered into
a Self Test routine by setting the UPPER FUNC-
TIONS-LOWER FUNCTIONS switch to IN and
pressing in the FREQ, PER, and WIDTH buttons at
the same time. The message “SELF tESt” will be
displayed on the readout to indicate that the rou­
tine is in self test mode. To exit from the routine
press in any of the CTM front panel buttons to re­
gain normal measurement mode. Repeated press­
ing of the SGL SWP RESET button will cause the
CTM to advance through the test menu. To exit
from the test menu, keep pressing the SGL SWP
RESET button until “End S-t” message is dis­
played on the readout. Then exit from the Self Test
routine by pressing in any one of the CTM front
panel buttons. Self Test routine should normally be
performed by a qualified service personnal.
(
37
)
A TIME POSITION Control— Used in conjunction with
the B DELAY TIME POSITION control in A TIME
mode. The control determines the time difference be­
tween the starts of the two intensified zones.
(3 8 ) Readout— Consists of a nine-digit vacuum fluores­
cent unit which is used to display measurements se­
lected by the CTM. No polarity indication is displayed
for positive values. Negative polarity indication is
automatic for negative values. In Counter and Timer
modes the decimal point is always placed in one of the
three most-significant digits, and the exponent is al­
ways an integer multiple of 3. Resistance measure­
ments are also displayed with an exponent. All
frequency measurements are in Hertz, and time mea­
surements are in seconds.
RIGHT-SIDE PANEL
Refer to Figure 2-8 for location of item 39.
39)
Multimeter Connectors— Two banana like jacks pro­
vide positive (red) and negative (black) inputs for volt­
ages, resistance, and temperature measurements.
REAR PANEL
Refer to Figure 2-9 for location of item 40.
(4 0 ) EXT Z-AXIS Connector— Provides a means of con­
necting external signals to the Z-axis amplifier to in­
tensity modulate the crt. Applied signals do not affect
display waveshape. Signals with fast rise times and
fall times provide the most abrupt intensity change,
and a 5-V p-p signal will produce noticeable modula­
tion. The Z-axis signals must be time-related to the
display to obtain a stable presentation on the crt.
2-9