Tektronix 549 Instruction Manual page 71

Performance Check— Type 549
c. Check— The screen
sweep, at a time determined by the V IE W IN G TIM E con­
trol setting, then the sweep automatically resets and starts
over.
43. Check Operation of Screen Selector
a. Requirement— SCREEN
either or both upper and lower screen for the erase program.
b. Change the SCREEN
position.
c. Check— The lower screen must erase in accordance
with the program set by the ERASE PROGRAM A U TO
ERASE switch and V IE W IN G TIM E control.
d. Change the SCREEN SELEC TO R switch to the UPPER
position.
e. Check— The upper screen must erase in accordance
with the ERASE PROGRAM, A U T O ERASE switch and V IE W ­
IN G TIM E control.
44. Check Writing Speed
a. Requirement— W ritin g speed is equal to or greater than
s.
0.5 cm/μ
b. Set the A TIM E/C M switch to 20 μ SEC position, the
A U TO ERASE switch to A FTER SW E E P and the V IE W IN G
TIM E control midrange. Set the SCREEN SELEC TO R switch
to F U LL position.
c. Apply an approximate 50 kHz sine-wave signal from
the signal genenator to the vertical plug-in unit and adjust
the output signal amplitude control fo r a display amplitude
of 3.2 cm.
d. Set the S TA B ILITY control to PRESET and adjust the
A LEVEL control for a stable display.
e. Carefully adjust the IN TE N S ITY , FO C US and A STIG
controls for optimum display storage. See Fig. 5-12A.
f. Increase the input frequency from the signal generator
and adjust the TIM E/C M switch setting and VARIABLE control
to maintain slightly more than 15 cycles per 10 cm until the
stored display shows breaks greater than 0.025 inches. See
Fig. 5-12B. (Maintain optimum storage by adjusting the
IN TE N S ITY , FO C US and A STIG controls.)
g. Check— The frequency of the sine wave generator
must be 50 kHz or higher. W ritin g speed in cm/μs = Fre­
quency in M H z X 10 (when the signal amplitude is 3.2 cm
and a display of 15 cycles/ 10cm is maintained).
45. Check Enhance Mode Operation
a. Requirement— Enhance mode operation must enhance
the writing speed to 5cm /μs or greater.
b. Change the EN H A N C E M O D E switch to FU LL position
and adjust the EN H A N C E LEVEL control fo r optimum stor­
age. Increase the input signal generator frequency and
adjust for optimum storage as in step 44, until breaks of
approximately 0.025 inches are noted.
5-14
automatically erases after
SELEC TO R switch must select
SELEC TO R switch to LO W E R
the
Fig. 5-12. Typical disp lay whan measuring writing speed.
c. Check— Frequency
writing speed in cm/μs = sine wave frequency in M H z X
10, and should equal 5 cm/μs or more.
d. Set the EN H A N C E M O D E switch to the UPPER and then
LO W ER position, checking enhance operation for each indi­
cated switch position.
e. Turn the EN H A N C E M O D E switch to O FF position.
4 6 . Check Integrate Traces O peration
a. Requirement— Depressing the IN TE G R A TE TRACES but­
ton must interrupt flood gun beam current and permit the
integrating of writing beam traces.
b. Set the A TIM E/C M switch to .1 mSEC, IN TE N S ITY con­
trol fully counterclockwise, N O RM -SIN G LE SW EEP switch to
SIN G LE S W EEP position and A U TO ERASE to O FF position.
c. Depress both ERASE buttons to erase the storage area
then depress the IN TE G R A TE TRACES button for 2 seconds.
d. Check— There must be no indication of fade positive
after the IN TEG R A TE button is released.
e. Increase the intensity level by turning the IN TE N S ITY
control clockwise, and depress the ERASE A N D RESET button
to trigger the sweep until a complete trace is stored.
f. Depress the IN TEG R A TE TRACES button.
g. Check— The stored trace should disappear with the
of the input signal. Enhanced