Tektronix TDS 420A, Service Manual, Page: 95 / 288

Performance Tests
TDS 420A, TDS 430A & TDS 460A Service Manual
4- 27
b. Match the trigger source to the channel selected:
H
Press TRIGGER MENU .
H
Press the main-menu button Source .
H
Press the side-menu button that corresponds to the channel selected.
c. Set the input impedance of the channel:
H
Press VERTICAL MENU ; then press the main-menu
button
Coupling
.
H
Press the side-menu button
Ω
to toggle it to the 50
Ω
setting.
d. Set the vertical scale: Set the vertical SCALE to one of the settings
listed in Table 4--3 (TDS 420A) or Table 4--4 (TDS 430A and
TDS 460A) not yet checked. (Start with the 100 mV setting.)
Table 4- 3: Analog Bandwidth (TDS 420A)
Vertical Scale Reference Amplitude Horizontal Scale Test Frequency Limits
100 mV 600 mV (6 divisions) 5 ns 200 MHz
≥
424 mV
1 V
4
2 V (2 divisions) 5 ns 200 MHz
≥
1.414 V
500 mV 2 V (4 divisions) 5 ns 200 MHz
≥
1.414 V
200 mV 1.2 V (6 divisions) 5 ns 200 MHz
≥
848 mV
50 mV 300 mV (6 divisions) 5 ns 200 MHz
≥
212 mV
20 mV 120 mV (6 divisions) 5 ns 200 MHz
≥
84 mV
10 mV 60 mV (6 divisions) 5 ns 200 MHz
≥
42 mV
5 mV 30 mV (6 divisions) 5 ns 200 MHz
≥
21 mV
2 mV 12 mV (6 divisions) 5 ns 150 MHz
≥
8.4 mV
1 mV 6 mV (6 divisions) 5 ns 95 MHz
≥
4.2 mV
4
If the oscilloscope does not trigger in step 2e, change the trigger coupling to DC for this Vertical Scale setting.