Operating Information—2445 Service
3.
Connect the Channel 1 probe (using the probe hook
tip) to the oscilloscope CALIBRATOR output.
4.
Set triggering controls for a stable display. The dis
play should be five cycles of the CALIBRATOR square-
wave signal, with an amplitude o f four divisions. Center the
display on the screen.
5.
Check the waveform for overshoot and ro llo ff (see
Figure 2-10). If necessary, use a small-bladed screwdriver to
adjust the probe low-frequency compensation for a square
fron t corner on the waveform.
6.
Release the CH 1 VERTICAL MODE switch, select
CH 2 VER TICAL MODE, and connect the Channel 2 probe
input to the CALIBRATOR output. Observe that the
CH 2 SCALE FACTOR on the readout display indicates
100 mV w ith the 10X probe attached.
7.
Use the Channel 2 POSITION control to vertically
center the display and repeat step 5 for the Channel 2
probe.
NOTE
Refer to the■
instruction manual supplied with the
probe fo r more complete inform ation about low-
frequency and high-frequency compensation o f
the probes.
1
-
I
/ O V E R C O M P E N S A T E D
r
I
N.
V
M
CORRECT
1
-
-
\ U NDER C O M P E N S A TE 3 /
1
1 0 0 m V
1 0 0 rn V
1 ms
i
I
3 8 30-1 2
Figure 2-10. Probe low-frequency compensation.
MATCHING CHANNEL 2 DELAY
The apparent signal delay in Channel 2 may be adjusted
up to ±500 ps to match the apparent delay present in any
of the other three channels. This adjustment is most com
monly used to eliminate delay differences between Chan
nel 1 and Channel 2 that may be introduced by the probes
and has no effect on common-mode rejection when ADD
VE R TIC A L MODE is selected. Matching Channel 1 and
Channel 2 delay is accomplished as follows:
1.
Preset the instrument controls and obtain a baseline
trace as described in "In itia l Setup."
2. Connect the two 10X probes (supplied w ith the
instrument) to the CH 1 OR X and CH 2 input connectors.
3. Check and adjust, if necessary, the probes' low-
frequency compensation. Refer to "Probe Low-Frequency
Compensation" in this section.
4. Connect both probes via hook tips to a pulse gener
ator fast-rise output.
5. Press in both the CH 1 and CH 2 VER TICAL MODE
switches.
6.
Set oscilloscope triggering controls fo r a stable
display.
7. Set the A AND B SEC/DIV switches to 10 ns.
8.
Adjust the Channel 1 and Channel 2 POSITION
controls to vertically overlay the two displayed signals.
9.
Pull out the B SEC/DIV switch and observe the
message CH 2 D ELAY — TURN A in the upper right-hand
corner of the screen.
NOTE
The 2445 can be set to preclude operator adjustment
o f Channel 2 delay. I f the delay-offset feature is
disabled, the message
CH 2 D LY DISABLED appears
in the top row o f the readout when attempting to
activate the feature. Refer the instrument to a
qualified service technician i f adjustment o f the
delay matching is required.
2-19
Содержание 2445
Страница 1: ...Tektronix 2445 OSCILLOSCOPE SERVICE INSTRUCTION MANUAL ...
Страница 11: ...2445 Service 3829 01 The 2445 Oscilloscope ...
Страница 44: ...Theory of Operation 2445 Service 3831 10A Figure 3 1 Block diagram ...
Страница 45: ...Theory of Operation 2445 Service 3831 10B Figure 3 1 Block diagram cont 3 3 ...
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Страница 247: ...A 1 C _____ D E F G H J 2445 3811 74 ...
Страница 248: ...1 2 3 4 5 6 7 8 9 i o 2445 DISPLAY SEQUENCER TRIG GERING A4B SWEEPS ...
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Страница 263: ... 0 2445 J8 i S ...
Страница 264: ...1 2 3 4 5 6 7 i 8 I i 9 10 2445 READOUT ...
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Страница 290: ...B H le w o q 87V T S o I R v n i U1 R1873 PARTIAL A9 HIGH VOLTAGE BOARD 2445 ...
Страница 299: ...2445 Service DAC REF A5 CONTROL ADJUSTMENT LOCATIONS 3 ...
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Страница 304: ...2 R E TU R N T O 1 ...
Страница 305: ...ERROR MESSAGE DIAGNOSTICS ...
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Страница 307: ...O A A C t rnra g i tiw c t 3829 89 ...
Страница 308: ...RETURN TO ...
Страница 309: ...FRONT PANEL TROUBLESHOOTING ...
Страница 310: ...FRONT PANEL TROUBLESHOOTING ...
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Страница 316: ...R E TU R N T O v 1 y ...
Страница 317: ...SWEEP TROUBLESHOOTING PROCEDURE ...
Страница 318: ...2445 Service NOTE 3 56V IS M E A S U R E D A S 1 44V W ITH R ESPEC T TO TH E 5V SUPPLY 3829 95 ...
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Страница 326: ... KERNEL NOP DIAGNOSTIC PROCEDURE ...
Страница 327: ...10 POWER SUPPLY TROUBLESHOOTING PROCEDURE 3829 94 ...
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Страница 334: ...2445 Service REGULATOR TROUBLESHOOTING PROCEDURE 3829 93 ...
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