Horizontal Display - Tektronix 585A Instruction Manual

c. Adjust test oscilloscope triggering controls for a stable
display.
d. Check-Test oscilloscope display is between 7.5 and
12.5 cycles in 10 centimeters (repetition rate of 1 kHz +25%).
17. Check Amplitude Calibrator Symmetry and
Risetime
a. Requirement-Symmetry within +10% (duty cycleh
risetime approximately 2 f-tS.
b. Change the test oscillscope Time/Cm switch and Vari-
able Time/Cm control to display one complete cycle in 10
cm.
c. Check-First half cycle duration is between 4 and
6cm.
d. Set the test oscilloscope Time/Cm switch to 1 f-ts
and set the Variable to the Calibrated position.
e. Adjust the Triggering Level control so the leading
edge of the signal is displayed, then adjust the Volts/Cm
selector and Variable for a 4-cm display amplitude.
f. Use the Horizontal Position control to center the dis-
play, then measure the risetime from the 10% to 90% ampli-
tude points.
g. Check-Risetime is typically 2/-ts or less. See Fig. 5-5.
h. Disconnect all test equipment.
90%
--_.
~-{
Ji
{;
!
10%
I
~--+i
!-
Measuring the risetime of a normal waveform;
sweep rate is 1 p.SECI CM.
Fig. 5-5. Measuring the risetime of a normal waveform; sweep
rate is 1 p.SEC!CM.
CHECK FRONT PANEL OUTPUT
WAVEFORM AND HOLDOFF TIME
18. Check Sawtooth A
a. Requirement-Sawtooth waveform with an amplitude
of approximately 140 volts +20 volts increasing to approxi-
mately 170 volts +20 volts at the faster sweep rates.
b. Connect the lOX probe from the test oscilloscope and
the plug-in unit to the SAWTOOTH A connector on the
Type 585A.
c. Set the controls as follows:
Performance Check-Type 5a5A
I
1
I t
I I
I
l
+t ....
Holdoff time
I I
Amplitude
+20 to
40 V
J.t
Zero v91t
reference
Fig. 5-6. Typical test oscilloscope display of the
+
GATE output
signal. Time! cm
=
10 p.SEC.
Type 585A
HORIZONTAL DISPLAY A
A TIME/CM .1 mSEC
TRIGGERING SOURCE INT AC
STABILITY and
TRIGGERING LEVEL
Fully clockwise for a
free running A sweep
Volts/Cm
Time/Cm
Test Oscilloscope
5
1 mSEC
.d. Adjust test oscilloscope triggering controls for a stable
display.
e. Check-Type 585A SAWTOOTH A output amplitude,
should be within 130 to 180 volts.
19. Check
+
Gate A and Time Base A
Holdoff Time
a. Requirement-Gate amplitude within 20 to 40 volts,
holdoff time within the item specified in Table 5-4.
b. Connect the lOX probe from the test oscilloscope to
the +GATE A connector.
c. Change the test oscilloscope Volts/Cm switch to 1
and the Time/Cm switch to 1 f-tSEc.
d. Check-Waveform amplitude of 20 to 40 volts and
holdoff time (lower portion of the square-wave display) as
specified in Table 5-4. See Fig. 5-6.
TABLE
5-4
TYPE 585A
TIME/CM
Test Oscilloscope
Holdoff
Setting Time/Cm Setting Time
.05 to .5 f-tSEC
1 /-tSEC 3-9 f-tS
1 to 50 f-tSEC
5 f-tSEC 15-40 f-tS
.1 to .5 mSEC
50 f-tSEC 150-400 f-tS
1 to 5 mSEC .5 mSEC 1.5-4 ms
10 to 50 mSEC
. 5 mSEC
15-40 ms
.1 to 5 SEC 50 mSEC 150-400 ms
5-7