Check X Bandwidth; Check Sweep Holdoff - Tektronix 2205 Service Manual

c. Position the trace horizontally so the start of
the trace begins at the first vertical graticule line (ex­
treme left).
d. Set the SEC/DIV switch
counterclockwise).
e. ADJUST—X Offset (R736) to position the spot
at the seventh vertical graticule line,
f. Disconnect the test equipment from the
instrument.

10. Check X Bandwidth

a. Set:
VOLTS/DIV (both)
AC-GND-DC (both)
Trigger SOURCE
b. Connect the leveled sine-wave generator out­
put via a 5 0 -ft coaxial cable and a 50-Xl termination
to the CH 1 X input connector.
o r
c. Set the generator to produce an 8-division
horizontal display at an output frequency of 50 kHz.
d. Increase the signal frequency until the hori­
zontal deflection (X-axis) is equal to 5.7 divisions in
length.
e. CHECK—The frequency is greater than 2 MHz.
f. Disconnect the test equipment from the
instrument.

11. Check Sweep Holdoff

a- Set:
VOLTS/DIV (both)
to X-Y (fully
AC-GND-DC (both)
SEC/DIV
Trigger SOURCE
b. Connect the test oscilloscope's 10X probe tip
to the front end of R704 (toward the front panel).
R704 is on the Timing circuit board.
c.
3.0 ms.
d. Repeat part c for SEC/DIV switch settings in
Table 5-5.
50 mV
DC
e. Disconnect the 10X probe from R704.
CH 1
Adjustment Procedure—2205 Service
CHECK—Holdoff time is between 1.5 ms
Table 5-5
Settings fo r Holdoff Checks
SiC/OIV
0.1 ms
0.2 ms to 0.3 ms
10 us
15 us to 30 us
1
1.5 us to 3.0 us
|1S
I V
GND
1 ms
EXT, EXT
Holdoff Time
5-15