Adjust X Gain; Check A-Sweep Holdoff - Tektronix 2235A Instruction Manual

Adjustment Procedure
-
2235A Instruction
Select 5-ps time markers from the time-mark
generator.
Adjust the Horizontal POSITION control so that the
rising edge of the displayed time marker is aligned
with the center vertical graticule line.
Without changing the Horizontal POSITION control
setting, turn the B DELAY TIME POSITION dial clock-
wise to position the next time marker leading edge to
the center vertical graticule line.
CHECK-The B DELAY TlME POSITION dial setting
is 0.980 to 1.020 greater than the previous setting.
Set the B DELAY TlME POSITION dial to the exact
integer setting.
Repeat parts r through u for each successive time
marker up to the marker corresponding to the B
DELAY TlME POSITION dial setting of 10.00.
Disconnect the test equipment from the instrument.
Adjust X Gain (R760)
Set:
10 mV
X-Y
b. Connect a 50-mV standard-amplitude signal via a
5 0 4 cable to the CH 1 input connector.
c. ADJUST-X Gain (R760) for exactly 5-divisions of
horizontal deflection.
d. Disconnect the test equipment from the instrument.
10. Check A-Sweep Hoidoff
a. Set:
Horizontal MODE A
A SECIDIV 1 ms
VAR HOLDOFF NORM
b. Connect the test oscilloscope and its 10X probe tip
to the front end of R707 (toward the front panel)
which is located on the Timing circuit board.
c. CHECK-The A-Sweep holdoff is greater than 3 ms
but less than 7 ms.
d. Rotate the VAR HOLDOFF control to the maximum
clockwise position (MAX).
e. CHECK-The A-Sweep holdoff has increased by a
factor of 10 or more.
f. Disconnect the test oscilloscope 10X probe from
R707.