Check Common-Mode Rejection Ratio; Check Channel Isolation - Tektronix 2235A Instruction Manual

Performance Check Procedure
-
2235A Instruction
b. Set the generator to produce a 50-kHz, 6-division
display.
c. Increase the generator output frequency until the
display amplitude decreases to 4.2 divisions.
d. CHECK- Generator output frequency is between 18
and 22 MHz.
e. Disconnect the test equipment from the instrument.
6. Check Common-Mode Rejection Ratio
a. Set:
BW LIMIT
VOLTSIDIV (both)
INVERT
Off (button out)
10 mV
On (button in)
b. Connect the leveled sine-wave generator output via
a 50-A2 precision cable, a 50-A2 termination, and a
dual-input coupler to the CH 1 and the CH 2 input
connectors.
c. Set the generator to produce a 50-MHz, 6-division
display.
d. Vertically center the display using the Channel 1
POSITION control. Then set the Vertical MODE
switch to CH 2 and vertically center the display using
the Channel 2 POSITION control.
e. Set the Vertical MODE switches to BOTH and ADD.
f. C H E C K - D ~ S ~ ~ ~ ~ amplitude is 0.6 division or less.
g. If the check in part f meets the requirement, skip to
part p. If it does not, continue with part h.
h. Set the Vertical MODE switch to CH 1.
i. Set the generator to produce a 50-kHz, 6-division
display.
j.
Set the Vertical MODE switch to BOTH.
k. Adjust the CH 1 or CH 2 VOLTSIDIV Variable control
for minimum display amplitude.
I. Set the Vertical MODE switch to CH 1.
m. Set the generator to produce a 50-MHz, 6-division
display.
n. Set the Vertical MODE switch to BOTH.
o. CHECK-Display amplitude is 0.6 division or less.
p. Disconnect the test equipment from the instrument.
7.
Check Channel Isolation
a. Set:
Vertical MODE CH 1
CH 1 VOLTSIDIV 1 V
CH 2 VOLTSIDIV
0.5 V
VOLTSIDIV Variable (both) CAL detent
INVERT
Off (button out)
Channel 2 Input Coupling GND
A SECIDIV 0.1 ps
b. Connect the leveled sine-wave generator output via
a 50-A2 precision cable and a 50-A2 termination to
the CH 1 input connector.
c. Set the generator to produce a 50-MHz, 5-division
display.
d. Set the CH 1 VOLTSIDIV switch to 0.5 position.
e. Set the Vertical MODE switch to CH 2.
f. CHECK- Display amplitude is 0.1 division or less.
g. Move the cable from the CH 1 input connector to the
CH 2 input connector.
h. Set:
Vertical MODE CH 1
Channel 1 Input Coupling GND
Channel 2 Input Coupling DC
i.
CHECK- Display amplitude is 0.1 division or less.
j.
Disconnect the test equipment from the instrument.
REV APR 1990
Scans by ARTEK MEDL4
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