Tektronix 494A Water Dispenser User Manual


 
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Adjustment
procedure
-
4g4Al4g4Ap
seMce
vot.
1
Figure
5-20-
lF
gain
test
setup,
and adjustnent
and
conn€ctor
rocason3-
12.
Adjust
B-SAVE
A
Reference
Level
(S1015
on
the
Verticat
Digitat
Storage
board)
when
B-sAVE
A is
selected,
the expression
imple-
mented
is
(B-sAVE
A)
+ kl,
where
k is'a
constant
set
by
the input
data
for
an
g-to-4
line
encoder,
u1015.
Each
bit will
move
the
reference
level
about
0.2
minor
division.
Normally,
the reference
level
is
set
at
the
center graticule
line;
however,
it can
be
set
anywhere
within
the
graticute
are3
!y
the
setting
of
an
g_bii
binary
switch,
S1015
(Figure
5-7).
The
MSB (switch
#8)
shifti
the
display
about
five
divisions,
swiich
#7
h;lf
this
amount,
etc.
The
following
procedure
sets
the refer-
ence
level.
Estimate
the
amount
and
direction
the
reference
level
is
to be shifted,
then
close or
open
the
switches
on
31015
to obtain
the
desired
B-SAVE
A reference
level.
13.
Adjust
Preselector
Driver
(Rl031,
Rl045,
Rl049,
Rl052,
R10s4,
Rl056,
R1061,
R1063,
R1064,
R1065, and
R2066
on
the
Preselector
driver board)
a.
Connect
the
test
equipment
as
shown in
Figure
5-21.
Calibrato.
Level
R1045
in
3rd Converter
lF
Gain
R1015
10 ltlHz
lF
Ampl
Tll
5O3
llain
Frame
10
dB
and 1 dB
Step
Attenuators
5-21