Tektronix 7a11 Instruction Manual page 61

P erfor m a n ce Check/Calibration-7A1 1
5-16) as necessary to obtain opti mu m s q uareness at tε ,
left corner of t
h
e squ are wa ves, duplicating the Calif .
F
i x tu re's 250 kH z disp lay . O vers
h
oot, rounding _--
s
h
ould be
w
it
h
in 0 .2
d
iv ision . Ig
n
ore any α [ at
may exist at t h e uaaer rig h t cor n er of the sαιι
Fig . 5-16 . Pro b e input compe n satio n adjustment locatio n s ; step 13,
j,
Disconnect the Probe from the 50 S2 Termination/
A d apter an(] replace t h e
P
robe cover,
k . Reconnect t h e Probe to the 50 S& Termination/
Adapter and recheck the squareness . Re p eat steps h
t h rough k if necessa ry .
η , Adjust the Square Wave Ge n erator as necessary to
obtai n α 250 kH z , 6 division display .
π . CHECK--Divide-by-400 input co mp e n sation . Over-
shoot, rou n ding and tilt at the top left corners of the square
waves Should be ιπιί t h ϊη 0 . .2 divisions of duplicating t h e Cali-
bratio n Fixtu re's 250 k H z Step Response display . Ignore
aberrations th at may e x ist at t h e rig h t cor n er of the square
waves .
ρ . It adjustment is req u i r ed , disconnect the P r obe fro m
the 50 Ω Term inatin η /Adapter arid remove the co ve
r
, T h en
recon n ect the Probe to t
h
e 50 Ω Tern ιί n α tion/Ad apte ί .
5-2 β
NOTE
1 . Remo ve the 5 Χ Attenuator .
r
τι . S w itc h the 7 Α 11
V
O
L
TS/D Ι V to 2 .
T h
e divide-by-20 ad
j
u
st
m
e
n
t also affects t
h
e divide-
by-400 presentation chec
k
ed in step 13- ο ,
( F ig . 5-16) to obtain opti mum
s
q
u
are n ess at t
h
e to p left
cor n er of th e s
q
u are
w
a ves . Overshoot, ro und ing and tilt
should be wit h in 0 .2 di v isio n of duplicating t
h
e Calibration
s 250 k H z
d
is p lay . Ignore aberrations at t h e rig h t
ί . Disco n nect the
P
robe from t h e 50 Ω Termination/
A d apter and re-i n stall t
h
e Probe cove r .
s . Re-connect the Probe to the 50 Ω Termination/
Adapter a n d rechec k the s
q
uaren ess . Repeat ste p s ρ
t
h rough s if
n
ecessa r y .
t . Disconnect the Probe f rom t h e 50 S2 Termination/
A d apter .
14 . Check
N
oise
REQ U IRE MEN T : Noise (tangentially measu red i n to α
7000-Series Oscilloscope) s h ould be within 0 .1 division,
α , Co n trol settings ap p ear i n Table 5-2, except that
νί d th is selected .
b . Set the Oscilloscope Time Base for α 2 ms/d έν trace
and line triggering . Adjust th e Oscillosco pe Intensity and
Focus for an optimum trace .
c . Switc
the sequence given :
A
tten u ato r , 50 Ω Term
7 Α 11 VOLTS,'DIV to 5 m V .
ng components to the Ty pe 106
e Generator
F
ast Rise i Output Connector in
10 Χ GR Atten ιaators, one
ε / A aapter, 7 Α 11 Ρ r οέι e t
e . At th e Type 106 Squa
r
e Wave Generato
r
, switch the
Repetitio n Rate Range to 100 kHz . Set the Hi Amplitu d e/
Fast Rise switch to Fast Rise a nd
a
d just the + Transition
A m plitu d e to o b tain two horizontal traces . See Pig . 5-17 .
T h en adjust t h e + Transitio n A mp litu de
u
ntil th e two traces
merge and t h e dar
k
li n e separating t h em disappears . Proper
adjustment is obtained
wh
e n d oubt e x ists as to whether or
n
ot th e li n e
h
as bee n eliminated,
f . Remove one 10 Χ Attenuator fro m
t
h e signal pat h .
g . CHECK--Noise, T race separation sho u l d be within 1
division . This represents
n
oise withi n 0 .1
d
i v isio n u n der
conditions obse r ved in step e .
I Q Α