Tektronix 1A5 Instruction Manual page 79

h. Set the A and B Input AC-GND-DC switches to GND.
i. R e move the test s tra p from TP 160 — TP260.
j. Check that the P O S ITIO
control are at m i drange and adjust R
trace to the center of the graticule.
k. Set the A and B Input AC
l. CHECK — 1 cm or less display amplitude. (CMRR 10,000
or greater).
m. ADJUST — C 1 22 or C222 and C 1 23 or C223 (Fig. 6-18)
for minimum display amplitude. (1 cm or less vertical display
amplitude for 10,00 0: 1 or greater common-mode rejection
ratio.)
NOTE
Use a non-metallic s crew
C 1 23, C223, C 1 63 and C263 so that their threads
are engaged by approximately two turns. When
adjusting, s cre w in only the one that improves com ­
mon-mode rejection in each pair.
F i g. 6-18. Adjustment locat
N control and STEP ATTEN BAL
1 70 (Fig. 6-18) to s e t the
- GND-DC switches to DC.
driver. P r eset Cl 22, C222,
i ons f or step 15.
n. Change the Cons
trol s e ttings to 500 mV and 10 MHz.
o. CHECK — 1 cm or less vertical display amplitude. (CMRR
1000 : 1 or greater).
p. ADJUST — E it her C 1 63 or C263 (Fig. 6-18) for minimum
disp l ay amplitude. 1 cm or less vertical disp
: 1 for 1000 : 1 or greater c
q. R epe at s t eps d, m, n and p until less than 1 cm display
amplitude exists for both s
r. Switch the VOLT
place the A and B Input AC - G ND-DC switches to the GND
position; disconnect the flexible T connector from the A and
B INPUT connectors.
s. S e t the oscillosc
s te p 14, parts a through n; then continue with s
t. INTER AC T I O N —
C a lib ra tion —
ta nt Amplitude Signal Generator con ­
l ay amplitude
o mmon-mode rejection.
t eps m and p.
S/ CM control to 20 mV; s i mul
o pe Triggering Slope to + and repeat
t ep 16.
Check steps 16 and 17.
Type 1 A5
t aneously
6-19