Tektronix 503, Instruction Manual

Page: 41 / 147

Performance Check— Type 503
-
(A ) C305C m isad ji sted
(B) C305C correctly a djusted
Fig. 5-5. H orizontal A m p lifie r attenua tor compensation check; 1 kHz square-wave input; SWEEP TIM E /C M switch setting, .1 mSEC.
SLOPE
+
COUPLING
AC
SOURCE INT.
LEVEL
FREE RUN
HORIZONTAL DISPLAY HORIZ. AMPLIFIER
(SWEEP DISABLED)
VERTICAL
SENSITIVITY
1 mV/CM
VARIABLE CALIBRATED
POSITION Midrange
+INPU T DC
-IN P U T GND
HORIZONTAL
SENSITIVITY
1 mV/CM
VARIABLE
CALIBRATED
POSITION Midrange
+ INPUT GND
-IN P U T GND
c. Connect a 50-ohm termination, a UHF T connector,
and two 50-ohm cables to the output connector of the
constant-amplitude signal
generator. If desired, two quick-
connect adapters (item 12 of Recommended Equipment)
may be installed at the Type 503 input ends of the cables,
to permit easy cable-switching.
NOTE
The tw o 50-ohm cables should be id e n tical to
assure symmetrical input to the tw o am p lifie rs
fo r phasing checks.
d. Connect the two cables to the VERTICAL and HORI­
ZONTAL + INPUT connectors.
e. Adjust the generator output for a 6-cm display (a
vertical line trace) at a frequency of 50 kHz, and center the
display vertically and horizontally.
f. Change the HORIZONTAL +IN P U T switch to DC. The
display w ill change to a single trace at a 45° angle, or an
extremely flattened ellipse with a small separation at the
center of the ellipse.
g. Check— Trace separation at the center (measured on
the graticule center Vertical line) must be not more than
1 mm (corresponding to 1 °). See Fig. 5-6 for method of
measuring phase difference.
h. Change the generator frequency to 350 kHz and adjust
the generator output for a 6-cm display horizontally and
vertically.
i. Check— Trace separation not more than 1 mm, meas­
ured as in step (g).
j. Change the generator frequency to 450 kHz, and adjust
the generator for a 6-cm display horizontally and vertically.
k. Check— Trace separation not more than 1 mm, meas­
ured as in step (g).
l
. Check the remaining attenuator positions through .2
VOLTS/CM, using steps (e) through (k) as a guide, and refer­
ring to Table 5-3 for attenuator settings, generator fre­
quencies, and trace separation tolerances.
m. Change the VERTICAL and HORIZONTAL +INPU T
switches to GND, the VERTICAL and HORIZONTAL — INPUT
switches to DC, and move the signal cables from the VERTI­
CAL and HORIZONTAL + INPUT connectors to the VERTI­
CAL and HORIZONTAL -IN P U T connectors.
5-8
CO