Cmrr - Tektronix 1A5 Instruction Manual

d. Set the DISPLAY switch to A-B.
e. S i mu l taneously set both AC-GND-DC switches to DC.
f. Switch the VOLT S/ CM control to 1 mV.
g. Set the oscillosc o pe Triggering Source to E
control to .5 ms and s e t the Triggering L
sweep.
h. CHECK — 2.5 mm or less vertical dis
between trailing edges of s
Dis re gard any aberra t ions that exist ne
the s q u a re waves.
i. ADJUST — COMMON MODE BAL (R
amplitude between the trailing edges of the s
( 2 .5 mm or less for 20,00 0: 1 CMRR in × 1 range). See Fig.
6-14 (C). Dis reg ard aberrations that may exist ne
ing edge of the s q u a re waves.
j. CHECK — × 10 and × 100 attenuator DC common-mode
balance for the s a me results as in h, us
Table 6-4.
k. ADJUST — × 10 and × 100 attenuator DC common ­
mode balance for the s a me results as in i. E
and adjustmen t s are lis t ed in Table 6-4, R
for location of adjustments. (2000
ranges.)
TABLE 6-4
×10 and ×100 DC Comm
S ta ndard
Type 1A5
VOL TS/ CM Amplitude
Settings Calibrator
Amplitude
Settings
50 V
10 mV
R e t a ined R a nge
1 0 0 V
.1 V
R eta ined R a nge
l. Switch both AC-GND-DC switches to GND.
m. Use of the S ta ndard Amplitude Calibrator has been
completed. Turn it off and disconnect the flexible T connector
from the A and B inputs, and the c
osc i llosc o pe Trigger Input.
n. Switch the VOLT S/ CM control to 20 mV.
x t, Tim e /cm
ev el to trigger the
p lay amplitude
q u a re waves (20,000 :

1 CMRR).

a r the beginning of
1 40) for minimum
q uare waves
a r the lead ­
i ng the s e tups given in
q u i pment s e tups
e fer to Fig. 6-14 (B)
: 1 CMRR in × 10 and ×1 00
on- Mode Adjustmen t s
Type 1A5 Vertical
Adjustments D i sp l ay
Amplitude
R 105 D 2.5 cm or less
R 1 06D 0.5 cm or less
o axial c a ble from the
Fig. 6-14. DC comm o n-mode balance, step 13. (A) and (B) Ad ­
justment locations; (C) Typical waveform.
vertical s ens itiv i ty 1 mV/cm)
C a libration — Type IA5
(Sweep rate 0.5 ms / cm;
6-15