Check/Adjust Ch 2 And Vertical Output High Frequency Compensation; Check Ch 2 Position Effect - Tektronix 465 Instruction Manual

f. Set the CH 2 VOL TS/ D IV switch to 50 mV .
g . CHECK-Disp lay for a flat-top waveform wi th 30/oor
less overshoot or ro ll-off on the leading edge.
h. ADJUST-Channel 2 C13 for the best flat-top
waveform . and Channel 2 C12 for the bes t front corner
with the low-capacitance screwdriver.
i. CAL AID-Remove the 20 picofarad normal izer
when adjusting or checking the front corner response.
j . INTERA CTIO N- Between Channe l 2's C13and C12 .
Readjust both for total optimum response.
k. Set the CH 2 VOL TS/ DIV sw itch to 0.5 V .
I. CHECK- Display for a flat-top waveform with 3% or
less overshoot or ro ll-off on the leading edge .
m . ADJUST -Channel 2 C11 for the best fla t-top
waveform , and Channe l 2 C10 for the best front corner
with the low-capacitance screwdriver.
n. INT ERACTI ON- Between Channe l 2's C11 and
C10 . Readjust both for optimum response.
o . Set t he CH 2 VOL TS/ DIV switch to 5 V. It may be
necessary to remove the 50 ohm BNC term in ation to get
5 divisions of d isplay at 5 volts/ div ision.
p. CHECK- D isplay for a flat-top waveform with 3% or
less overshoo t or ro ll-off o n t he lead ing edge .
q . D isconnect the test setup .
24. Check/ Adjust Ch 2 and Vertical Output High
Frequency Compensation
a .
Set:
CH 1
&
CH 2 VOL TS/ D IV 5 mV
A T IM E/ DIV 0.05 µs
b. Connect the fast rise , positive output of the square-
wave generator to the CH 2 input via a GR to B NC adapter ,
50 ohm BNC cable, X10 BNC Attenuator and 50 ohm BNC
termination .
@
Callbration - 465 Service (SN 8250000 & up)
NO TE
Steps 24 through 29 are adjustment related. Perform
all the r;hecks in each of these steps before making
any adjustments (unless calibration is being per-
formed after repair or repla ceme nt of vertical com-
ponents ).
c . Adjust the square-wave generator for a 5 division
disp lay of a 100 k ilohertz signal. Add or remove
attenuators as needed to maintain a 5 division display
throughout this step.
d . CHECK- Display for a flat-top waveform with
aberrations of 3% peak-to-peak or less (0 .15 div ision
peak-to-peak for a 5 division display) .
e. CHEC K- Disp lay for a risetime of 3.5 na noseconds
or less.
f.
ADJUST-C77 , C83 , C205, R205 , C249 and R249 on
the Preamp board . Also C4428, R4438, C4422 , R4422 on
the discrete Vertical Outpu t board .
A lso C403 , C442 , R442 and C443 on the IC Vert ical
Output board .
Ad ju st for the best flat-top display with aberrations of
3% peak-to-peak or less and a r isetime of
3.5 nanoseconds or less.
g. Move the test setup to the fast rise, negative output
of the square-wave generator.
h . Set the A TRIGGER SLOPE swi tch to-.
i.
CHECK- Display for a flat-bottom waveform with
aberrations of 5% peak-to- peak or less. (0.25 divis ion
peak-to -peak for a 5 div ision display.)
25. Check Ch 2 Position Effect
a. Positio n the bottom of the display to the top
horizonta l g raticule line.
b. CHECK-Display for a flat-bottom waveform with
aberrations of 7% peak-to-peak or less (0.35 division with
a 5 division display) .
c. Pos it ion the bottom of the display to the bottom
horizontal graticule line.
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