HP 203A - Adjustable Phase Shifter (А25); Adjustment

Моде! 203А
5-16. ADJUSTABLE PHASE SHIFTER (А25)
ADJUSTMENT.
( Note
The following procedure must be performed
with
printed
board
A2
in
its
normal
operating
position
in
the
Model
203A.
Do
not
use
ап
extender board.
a.
Connect
АС
Voltmeter
across
output
of
Phase
Shifter
Assembly
(A25)
using
short
unshielded
leads
(see
figure
5-8).
b.
While
rotating
PHASE
LAG
dialthrough
3609
alternately
adjust
A2C1
(see
figure
5-11)
and
A25C1
until
voltage
levelindicated
on
AC
Voltmeter
remains
with
+3%
of
nominal
signal
level
obtained.
5-17.
RF
AMPLIFIER
ADJUSTMENT
(A2).
a.
Connect
DC
Voltmeter
tothe
collector
of
А293:
connect
10:1
Oscilloscope
probe
to
collector
of
А204.
(See
figure
5-11.)
b,
Adjust
A2L3
for
maximum
DC
Voltmeter
reading.
с.
Adjust
A2T1
for
minimum
AC
voltage
indication
on
Oscilloscope.
Ч.
Repeat
steps
b
and
с
as
many
times
аз
neces-
(
sary
for
optimum
adjustment.
е. Connect DC Voltmeter to collector of A2Q7;
connect
10:1
Oscilloscope
probe
to
collector
of
A2Q8.
f.
Adjust
A2L7
for
maximum
DC
Voltmeter
read-
ing.
є.
Adjust
A2T2
for
minimum
AC
Voltage
indication
on
Oscilloscope.
В.
Repeat
steps
f
and
gas
many
timesas
necessary
for
optimum
adjustment.
5-18.
DECADE
MODULE
А11
ADJUSTMENT.
Note
Each
of
the
six
Decade
Modules,
A11
through
А16
are
electrically
identical.
Each
module
Should
be
adjusted
in
the
1K
position
of
the
range
switch
for
best
results.
All
components
are
referred
to
by
their
location
on
the
mod-
ule.
Forexample,
L1is
A11L1,
АЛ
21,1,
A13L
1,
etc.
depending
upon
the
particular
module
under
test.
Module
All
procedure
is
given
Separately
because
of
its
wide
frequency
range.
а.
Connect
a
10:1
Oscilloscope
probe
to
the
junction
of
CR1
and
CR2
(seefigure
5-
13b)
and
see
the
controls
as
follows:
SENSITIVITY . 02v/cm
SWEEP
TIME
2
usec/cm
TRIGGER
SOURCE
INT
-
-
01760-3
Section V
Paragraphs
5-16
to
5-18
b.
Set
the
frequency
dial
to
5
and
the
range
Switch
to
1K.
c.
Adjust
T1
and
L1
for
maximum
amplitude
the
5
me
signal.
Note
Li
may
have
two
peaks.
The
correct
position
of
the
slug
is
the
second
peak
in
the
clockwise
direction.
The
wrong
position
of
the
slug
will
be
noted
by
a
sawtooth
waveform.
d.
Move
the
10:1
Oscilloscope
probe
to
the
base
of
©З
and
change
the
vertical
sensitivity
to
.
05v/cm.
e.
Adjust
T2
for
maximum
amplitude
of
the
5
mc
signal.
f.
Move
the
10:1
Oscilloscope
probe
to
the
emitter
of
Q3.
g.
Adjust
L2for
eleven
complete
cycles
in
10
ст
of
horizontaldeflection.
(See
figure
5-7,
waveform
12.)
h.
Move
the
10:1
Oscilloscope
probe
to
the
base
of
Q3.
21.
Rotate
the
frequency
dial
slowly
to
the
high
end.
The
amplitude
of
the
5
mc
signal
should
not
fall
below
1
cm
(.
5v
p-p.)
j.
If
the
signal
at
the
high
end
of
the
dial
is
tc
low
in
amplitude,
turn
L1
slug
counterclockwise
.
until
1
em
of
amplitude
is
obtained,
Rotate
the
fre-
quency
dial
from
the
high
end
to
the
low
end
and
stagger
tune
1,1
and
ТІ
as
necessary
in
order
to
maintain
at
least
1
cm
of
amplitude
over
the
entire
range.
k.
Movethe
10:1
Oscilloscope
probe
to
the
emitter
of
Q3
and
set
the
frequency
dial
to
5.
l. Turn L2 slug clockwise until the waveform
goes
out
of
sync.
Next
turn
L2
slug
counterclock-
wise until the waveform just comes back into sync.
m.
Rotate
the
frequency
dial
slowly
toward
the
high
end
until
the
waveform
goes
out
of
sync.
n. Turn L2 slug counterclockwise until the wave-
form just comes back into syne.
o. Repeat steps m and n until the waveform is
synchronized while rotating the dial between the
extreme tugh and low ends,
p. Rotate the frequency dial until the first pip-
on the waveform is at maximum amplilude, :
Ч.
Turn
12
slug
counterclockwise
to
reduce
the
. amplitude of the first pip to one-half the amplitude noted
instepp. The bottom of the first pip will he slightly low-
er inamplitude than any other part of the waveform.
5-7