Check Total Crosstalk - Tektronix 1A5 Instruction Manual

F i g. 6-23. High-f r equency com p e
Adjustment locations; ( B) Waveform for steps
µ
(sweep rate 0.1 s/cm ) ; (C) Wavefo
µ
0.01 s / cm ) . Ve rt ical s ens i tiv i t y 20 mV/cm or as given in Table 6-8.
i. CHECK — Squareness and F
of s q uare wave. (S e e F i g. 6-23).
j. ADJUST — C379, R 3 79, C389 and R
mum flatness and squareness at the upper left corner of the
s q u a re wave as sho wn in F i g. 6-23 (A) and (B).
k. Switch the oscillosc o pe Sweep Magnifier control to
X10 . ( 10 ns/cm is n o w being displayed.)
l. CHECK — 7 ns or less rise time between the 10% and
90% points as shown in F i g. 6-23 (C). R
es sa ry to obtain 7 ns or less rise time.
nsat ion adjustment, step 20. (A)
20-g through j,
r m for step 20 - 1, (sweep rate
l atness of upper left corner
3 89 to provide opt
epea t s t ep j if nec ­
m. CHECK — Flatness and squareness at the upper left
corner of a 5 cm s q u
6-7.
n. ADJUST — High frequency
time in each gain switching s en
Table 6-7, following the same general procedure as in steps
g through k. See F i g. 6-23A for location of a
Gain Switching High F
VOL TS/ CM Sweep
Magnifier
10 mV
×10
5 mV
×10
Ins e r t a 10 : 1 50-
the GR cable and the 5:1 attenuator
2 mV
×10
1 mV
×10
o. INTER ACT I O N — Step 24.
21. Check Total Cross
a. Equ i pment s e tup is
forms are shown in F
b. R e move the 10:1 attenuator (ins
c. Switch the osc i
Normal ( ×1 ) and Time/cm to . 5 ms. Set the Horizontal Posi ­
tion controls to midrange.
d. Switch the VOLT
e. Change the S q
kHz and adjust the + Transition Amplitude to provide a 5 cm
presentation.
f. Check for a s q
as in Fig. 6-24 (A).
g. Switch the B Input AC-GND-DC control to DC.
h. CHECK — 2.5 mm or less A INPUT roll-off at upper left
c o rner of s q u a re wave. See F
i. Switch the A Input AC-GND-DC control to GND and
move the termination and c
i ­
j. Check for a s q
as in F i g. 6-24 (C).
k. Switch the A Input AC-GND-DC control to DC.
l. CHECK — 2.5 mm or less B INPUT roll-off at lower left
c o rner of s q u a re wave. See Fig. 6-24. (D).
m. Disconnect the equipment from the B INPUT connector.
Calibration — T
a re wave in each setup given in Table
response and check
si ti v i t y position according to
d justments.
TABLE 6-7
r equency Adjustmen
Adjust
×1 L3 12/ R312
R 307/ C309
×1
Ω GR Type attenuator between
×1 R 304/ C305
×1 R301 /C302
t alk
sho wn in Fig. 6-22. Typical wave ­
i g. 6-24.
er ted in s t ep 20 n).
lloscope Horizontal Disp la y control to
S/ CM control to 20 mV.
uare Wave Generator Frequency to 1
u a re upper left corner of s q
i g. 6-24 (B).
a ble to the B INPUT connector.
u a re lower left corner of s q
y pe 1A5
rise
t s
Rise
Time
<7 ns
<7 ns
<8 ns
<9 ns
u a re wave
u a re wave
6-25