Tektronix 7613 User Manual

Calibration—7613/R7613 Service
f. Set the VERT MODE switch to RIGHT.
g. CHECK—Deflection between the second and sixth
traces should be the same as part d or e 1%.
h. ADJUST—If necessary, re-adjust R447 for correct
tolerance in both parts d and h,
14. Check Vertical Linearity
a. Remove the mainframe standardizer calibration
fixture. Install the 7A15A in the left vertical compartment
and connect a 0.4 volt square wave signal from the
CALIBRATOR out jacks, Set the VERT MODE switch to
left.
b. Set the 7A15A Volts/Div switch to 0.2 volt/division.
Adjust the position control to keep the display centered on
the graticule and adjust the Variable Volts/Div control if
needed for a two division display.
c. CHECK-—Position the two divisions of display verti-
cally and check for not more than 0.1 division of
compression or expansion anywhere within the graticule
area. Remove the 7A15A and install the mainframe
standardizer calibration fixture.
15. Adjust Vertical High-Frequency Compensation
a. Set the calibration fixture Test switch to Vert or
Horiz +Step Resp, Rep Rate switch to 250 kHz, and adjust
the Amplitude control for a six-division display.
b. Set the 7B53A for a calibrated sweep rate of five
nanoseconds/division (use X10 magnifier). Set the trigger
source switch internal adjust trigger level control and
position control for a stable display, centered on the
graticule.
ec. CHECK—Check for optimum square corner and flat
top on displayed pulse with aberrations not to exceed +0.1
or —0.1 division with total peak-to-peak aberrations not to
exceed 0.1 division.
d. ADJUST—Long term flat response R455 and R465
for a flat-top pulse with positioning from top to bottom of
screen,
e. ADJUST—High-frequency compensation as given in
Table 2-2 for optimum square leading corner and flat top
with minimum aberrations within limits given in part c.
Location of adjustments is shown in Fig. 2-3. Use the
low-capacitance screwdriver to adjust the variable
capacitors. Repeat the complete adjustment procedure
several times to obtain optimum adjustment.
2-10
TABLE 2-2
High-Frequency Compensation
Primary Area
Adjustment | Of Pulse Affected | Best Sweep Rate
C420 and First 50 nano- 50 nanoseconds/
R421 seconds division
R425, C425, First 20 nano- 20 nanoseconds/
L474, and L478 | seconds division
C427 and First 5 nano- 20 nanoseconds/
R427 seconds divisions
f. Remove the calibration fixture from the left vertical
compartment and install it in the right vertical compart-
ment.
g. Set the VERT MODE switch to RIGHT.
h. CHECK—Optimum square leading corner and flat top
on the displayed pulse with aberrations not to exceed +0.1
or —0.1 division, with total peak-to-peak aberrations not to
exceed 0.1 division.
i. ADJUST—If necessary, compromise the adjustment of
C420, R421, R425, C425, L474, L478, C427, and R427
for best response from both the left and right vertical
compartments.
j. To verify correct high-frequency compensation,
perform the bandwidth check as given in next step.
16. Check Vertical Amplifier Bandwidth
a. Connect the high-frequency constant-amplitude signal
generator to the CW In connector of the mainframe
standardizer calibration fixture.
b. Set the Test switch of the calibration fixture to Vert
or Horiz Freq Resp.
c. Set the 7B53A for a sweep rate of 0.2 microsecond/
division.
d. Set the high-frequency generator for six divisions of
deflection, centered on the graticule, at a reference fre-
quency of 3 megahertz.
e. Without changing the output amplitude, increase the
output frequency of the high-frequency generator until the
display is reduced to 4.2 divisions (—3 dB point).
7613

Tektronix 7613 Specifications

General

Brand	Tektronix
Model	7613
Category	Test Equipment
Language	English