Initial Control Settingsprocedure Steps

1. Adjust Vertical Gain (R186, R286, R145, and R245)

a. Connect a 100-mV standard-amplitude signal via a 50-Î2 cable to the CH 1 OR X input connector.

b. ADJUST-Ch 1 Gain (R186) for an exact 5-division display.

c. Move the cable from the CH 1 OR X input connector to the CH 2 OR V input connector. Change the VERTICAL MODE switch to CH 2.

d. ADJUST-Ch 2 Gain (R286) for an exact 5-division display.

e. Change the generator output to 10 mV and set the CH 1 and CH 2 VOLTS/DIV switches to 2 mV.

f. ADJUST-Ch 2 X10 Vert Gain (R245) for an exact 5-division display.

g. Move the cable from the CH 2 OR Y input connector to the CH 1 OR X input connector. Change the VERTICAL MODE switch to CH 1.

h. ADJUST-Ch 1 X10 Vert Gain (R145) for an exact 5-division display.

POWER

ON (button in)

AUTO INTENSITY AUTO FOCUS

As desired

Best focused display

Vertical (both)

POSITION VERTICAL MODE VOLTS/DIV VOLTS/DIV Variable INVERT AC-GND-DC

Midrange

CH 1

20 mV

CAL detent

Normal (button out)

Horizontal

POSITION

HORIZONTAL MODE SEC/DIV SEC/DIV Variable X10 Magnifier

Midrange NO DLY 0.5 ms CAL detent Off (knob in)

Trigger

VAR HOLDOFF TRIGGER MODE TRIGGER SLOPE TRIGGER LEVEL INT

SOURCE

NORM AUTO S

Midrange VERT MODE INT

2. Adjust Attenuator Step Balance (R138 and R238)

a. Set both AC-GND-DC switches to GND.

b. Set the CH 1 VOLTS/DIV switch to 10 mV and position the trace on the center horizontal graticule line using the Channel 1 POSITION control.

c. Change the CH 1 VOLTS/DIV switch to 2 mV.

d. ADJUST-Ch 1 Step Bal (R138) to set the trace on the center horizontal graticule line.

e. Repeat parts b through d until there is no trace shift when changing the CH 1 VOLTS/DIV switch from 10 mV to 2 mV.

f. Change the VERTICAL MODE switch to CH 2.

g. Repeat parts b through e for Channel 2, adjusting Ch 2 Step Bal (R238) in step d.

3. Adjust Attenuator X10 Balance (R146 and R246)

a. Set the CH 2 VOLTS/DIV switch to 20 mV.

b. Position the trace on the center horizontal graticule line using the Channel 2 POSITION control.

c. Change the CH 2 VOLTS/DIV switch to 10 mV.

d. ADJUST-Ch 2 X10 Bal (R246) to set the trace on the center horizontal graticule line.

e. Repeat parts a through d until there is no trace shift when changing the CH 2 VOLTS/DIV switch from 20 mV to 10 mV.

f. Change the VERTICAL MODE switch to CH 1.

g. Repeat parts a through e for Channel 1, adjusting Ch 1 X10 Bal (R146) in step d.

4. Check Deflection Accuracy and Variable Range a. Set:

CH 1 VOLTS/DIV 2 mV

CH 2 VOLTS/DIV 10 V

b. CHECK—Deflection accuracy is within the limits given in Table 5-3 for each CH 1 VOLTS/DIV switch setting and corresponding standard-amplitude signal. When at the 20-mV VOLTS/DIV switch setting, rotate the CH 1 VOLTS/DIV Variable control fully counterclockwise and CHECK that the display decreases to 2 divisions or less. Then return the VOLTS/DIV Variable control to the CAL detent and continue with the 50-mV check.

Table 5-3 Deflection Accuracy Limits

VOLTS/DIV Switch Setting

Standard Amplitude Signal

Vertical Deflection (Divisions)

3% Accuracy Limits (Divisions)

2 mV

10 mV

5

4.85 to 5.15

5 mV

20 mV

4

3.88 to 4.12

10 mV

50 mV

5

4.85 to 5.15

20 mV

0.1 V

5

4.85 to 5.15

50 mV

0.2 V

4

3.88 to 4.12

0.1 V

0.5 V

5

4.85 to 5.15

0.2 V

1 V

5

4.85 to 5.15

0.5 V

2 V

4

3.88 to 4.12

1 V

5 V

5

4.85 to 5.15

2 V

10 V

5

4.85 to 5.15

5 V

20 V

4

3.88 to 4.12

10 V

50 V

5

4.85 to 5.15

c. Set the VERTICAL MODE switch to CH 2 and move the cable from the CH 1 OR X input connector to the CH 2 OR Y input connector.

d. CHECK-Deflection accuracy is within the limits given in Table 5-3 for each CH 2 VOLTS/DIV switch setting and corresponding standard-amplitude signal. Perform the checks from the bottom to the top of Table 5-3 to avoid unnecessary switch-position changes. When at the 20-mV VOLTS/DIV switch setting, rotate the CH 2 VOLTS/DIV Variable control fully counterclockwise and CHECK that the display decreases to 2 divisions or less.

Then return the VOLTS/DIV Variable control to the CAL detent and finish the check.

5. Check Input Coupling a. Set both VOLTS/DIV switches to 50-mV.

b. Set the calibration generator to produce a 200-mV standard-amplitude signal.

c. Position the bottom of the signal on the center horizontal graticule line using the Channel 2 POSITION control.

d. Set the Channel 2 input coupling switch to AC.

e. CHECK-Display is centered about the center horizontal graticule line.

f. Set the VERTICAL MODE switch to CH 1 and move the input signal from the CH 2 OR Y input connector to the CH 1 OR X input connector.

g. Repeat parts c through e for Channel 1.

6. Check ALT and CHOP Operation a. Set:

VERTICAL MODE BOTH-ALT

AC-GND-DC (both) GND

SEC/DIV 10 ms b. CHECK-Display alternates between the Channel 1 and Channel 2 displays. If necessary, use both POSITION controls to separate the two traces.

c. Set VERTICAL MODE to CHOP.

d. CHECK-Channel 1 and Channel 2 displays are both displayed simultaneously.

7. Check VOLTS/DIV Variable Control Trace Shift a. Set:

VERTICAL MODE CH 1

VOLTS/DIV (both) 2 mV

SEC/DIV 0.2 ms b. Center the trace on the center horizontal graticule line using the Channel 1 POSITION control.

c. Rotate the CH 1 VOLTS/DIV Variable control counterclockwise through its full range.

d. CHECK-That the trace does not shift more than 2.5 divisions.

e. Return the CH 1 VOLTS/DIV Variable control to its CAL detent.

f. Set the VERTICAL MODE switch to CH 2.

g. Repeat parts b through e for Channel 2.

8. Adjust Invert Balance (R264)

a. Set the CH 2 VOLTS/DIV switch to 20 mV.

b. Center the trace on the center horizontal graticule line using the Channel 2 POSITION control.

c. Push in the INVERT button.

d. ADJUST—Invert Bal (R264) to position the trace on the center horizontal graticule line.

e. Return the INVERT button to Normal (button out).

f. Repeat parts c through e until there is no trace shift when switching the INVERT button between Invert and Normal.

9. Adjust Trigger Balance (R154)

a. Set the INT switch to CH 2.

b. Connect the digital voltmeter low lead to chassis ground (TP501) and the volts lead to pin 16 of U421; note the voltage reading for use in part d.

c. Set the INT switch to CH 1.

d. ADJUST-Ch 1/Ch 2 Balance (R154) so that the voltage reading is the same as that obtained in part b.

e. Disconnect the test setup.

10. Adjust Attenuator Compensation (C105, C104, C111, C110, C205, C204, C211, and C210)

CH 1 VOLTS/DIV 20 mV

SEC/DIV 0.2 ms b. Connect a 1-kHz, high-amplitude square wave via a 50-Î2 termination, a probe-tip-to-bnc adapter, and a P6120 Probe to the CH 1 OR X input connector.

c. Set the generator output to produce a 5-division display and compensate the probe using the probe compensation adjustment (see the probe instruction manual).

e. Replace the probe and probe-tip-to-bnc adapter with a 50-Î2 cable.

f. Adjust the generator output for a 5-division display.

NOTE

Use Table 5-4 to identify the correct capacitor for each channel adjustment.

g. ADJUST—The+10 LF Comp capacitor for best front corner.

Table 5-4

Attenuator Compensation Adjustments

Table 5-4

Attenuator Compensation Adjustments

Adjustment

Channel 1

Channel 2

+10 LF Comp

C105

C205

+ 10 Input C

C104

C204

+100 LF Comp

cm

C211

+100 Input C

C110

C210

h. Replace the cable and 50-i2 termination with the P6120 Probe and probe-tip-to-bnc adapter.

i. Adjust the generator output for a 5-division display.

j. ADJUST—The +10 Input C capacitor for best flat top.

k. Repeat parts e through j until no further improvement is noted. Add the 50-J2 termination to the cable in part e.

I. Set the CH 1 VOLTS/DIV switch to 2 V.

m. Replace the probe and probe-tip-to-bnc adapter with the 50-Î2 cable.

n. Adjust the generator output for a 5-division display.

o. ADJUST-The +100 LF Comp capacitor for best front corner.

p. Replace the 50-ii cable with the probe and probe-tip-to-bnc adapter.

q. Adjust the generator output to produce a display as close as possible to 5 divisions.

r. ADJUST-The +100 Input C capacitor for best flat top.

s. Repeat parts m through r until no further improvement is noted.

t. Set the VERTICAL MODE switch to CH 2.

u. Repeat parts b through s for Channel 2.

v. Disconnect the test setup.

11. Adjust Vertical Output Amplifier Compensation (R357, C357, R367, R366, and C366)

VOLTS/DIV (both) 20 mV

SEC/DIV 0.05 ¿is b. Connect a 1-MHz, positive-going fast-rise square-wave via a 50-S2 cable, a 10X attenuator, and a 50-S2 termination to the CH 2 OR Y input connector.

c. Adjust the generator output for a 5-division display.

d. Preset High Freq Comp (R357) fully counterclockwise.

e. ADJUST—High Freq Comp (C357) until ringing just disappears on the front corner.

f. ADJUST-Low Freq Comp (R367) and Mid Freq Comp (R366 and C366) for best flat top beyond 20 ns from the corner.

g. ADJUST—R357 and C357 for best corner on the first 20 ns of the displayed signal.

h. Repeat parts f and g until no further improvement is noted.

i. Set the CH 2 VOLTS/DIV switch to 0.1 V and repeat parts f and g for best compromise with the 20-mV VOLTS/ DIV switch setting.

j. Disconnect the test setup.

12. Adjust Channel Matching (C167) and Check Bandwidth a. Set:

VOLTS/DIV (both) 20 mV

SEC/DIV 20 ¡is b. Connect the leveled sine-wave generator output via a 50-S2 cable and a 50-S2 termination to the CH 2 OR Y input connector.

c. Set the generator output for a 5-division, 50-kHz display.

d. Increase the generator frequency until the display reduces to 3.5 divisions.

e. Move the signal from the CH 2 OR Y input connector to the CH 1 OR X input connector. Set the VERTICAL MODE switch to CH 1.

f. ADJUST-CH 1 & CH 2 HF Match (C167) for a vertical display amplitude of 3.5 divisions.

g. Set both VOLTS/DIV switches to 2 mV.

h. Set the generator output amplitude for a 5-division, 50-kHz display.

i. Change the generator output frequency to the value shown in Table 5-5 for the corresponding VOLTS/DIV switch setting.

Table 5-5 Settings for Bandwidth Checks

VOLTS/DIV

Generator

Switch Settings

Output Frequency

2 mV to 10 mV

50 MHz

20 mV to 10 V

60 MHz

j. CHECK—Display amplitude is 3.5 divisions or greater.

k. Repeat parts h through j for all indicated CH 1 VOLTS/DIV switch settings, up to the output-voltage upper limit of the sine-wave generator being used.

I. Move the generator output signal from the CH 1 OR X input connector to the CH 2 OR Y input connector. Set the VERTICAL MODE switch to CH 2.

m. Repeat parts h through j for all indicated CH 2 VOLTS/DIV switch settings up to the output-voltage upper limit of the sine-wave generator being used.

n. Disconnect the test setup.

13. Check Common-Mode Rejection Ratio a. Set both VOLTS/DIV switches to 20 mV.

b. Connect a 10-MHz, leveled sine-wave signal via a 50-f2 cable, a 50-f2 termination, and a dual-input coupler to the CH 1 OR X and the CH 2 OR Y input connectors.

c. Set the generator output amplitude to produce a 6-division display.

d. Vertically center the display using the Channel 2 POSITION control. Then set VERTICAL MODE to CH 1

e. Disconnect the test setup.

10. Adjust Attenuator Compensation (C105, C104, C111, C110, C205, C204, C211, and C210)

CH 1 VOLTS/DIV 20 mV

SEC/DIV 0.2 ms b. Connect a 1-kHz, high-amplitude square wave via a 50-Î2 termination, a probe-tip-to-bnc adapter, and a P6120 Probe to the CH 1 OR X input connector.

c. Set the generator output to produce a 5-division display and compensate the probe using the probe compensation adjustment (see the probe instruction manual).

e. Replace the probe and probe-tip-to-bnc adapter with a 50-Î2 cable.

f. Adjust the generator output for a 5-division display.

NOTE

Use Table 5-4 to identify the correct capacitor for each channel adjustment.

g. ADJUST—The+10 LF Comp capacitor for best front corner.

Table 5-4

Attenuator Compensation Adjustments

Table 5-4

Attenuator Compensation Adjustments

Adjustment

Channel 1

Channel 2

+10 LF Comp

C105

C205

+ 10 Input C

C104

C204

+100 LF Comp

cm

C211

+100 Input C

C110

C210

h. Replace the cable and 50-i2 termination with the P6120 Probe and probe-tip-to-bnc adapter.

i. Adjust the generator output for a 5-division display.

j. ADJUST—The +10 Input C capacitor for best flat top.

k. Repeat parts e through j until no further improvement is noted. Add the 50-J2 termination to the cable in part e.

I. Set the CH 1 VOLTS/DIV switch to 2 V.

m. Replace the probe and probe-tip-to-bnc adapter with the 50-Î2 cable.

n. Adjust the generator output for a 5-division display.

o. ADJUST-The +100 LF Comp capacitor for best front corner.

p. Replace the 50-ii cable with the probe and probe-tip-to-bnc adapter.

q. Adjust the generator output to produce a display as close as possible to 5 divisions.

r. ADJUST-The +100 Input C capacitor for best flat top.

s. Repeat parts m through r until no further improvement is noted.

t. Set the VERTICAL MODE switch to CH 2.

u. Repeat parts b through s for Channel 2.

v. Disconnect the test setup.

11. Adjust Vertical Output Amplifier Compensation (R357, C357, R367, R366, and C366)

VOLTS/DIV (both) 20 mV

SEC/DIV 0.05 ¿is b. Connect a 1-MHz, positive-going fast-rise square-wave via a 50-S2 cable, a 10X attenuator, and a 50-S2 termination to the CH 2 OR Y input connector.

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