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dt
4.
S<ternally oodulate the
RF
signal
generator
r*ith the tlo-tone
oscilLator,
naking sure
eaeh
tone
is
nodulated
at
3KtIa
deviation.
C.
CJ.ock
adjustnents
L.
Using
a
frequency counter
-
a.
Connect
a high input
i.npedance
anplifier to
Fin 1
of
IC3O1
in
tbe
radi.o.
b.
Connect
the output
of
tbb
aoplifier to
the input
of
an
acc-urate
frequency counter.
c.
Adjust
R3O1
until
the
counter reads
eight
tiares the value
of
'
the
first
tone
(ltone A).
d. Aewve
the
end of, JO3OI
ttrat
eonnects
!'rit!t Pin 1
of
1C301
'nd
1et
t!:at
end hang
free.
e.
Disconnect
the
probe
of
the
aqlifier
going
to
Pin
I of
IC3O1
and connect
it to
Pin 1
of,
IC3O2.
t.
Adjust
R318
r:ntil
a
frequency
of eight tines
tone frequency
B
is
read on
the
frequeney couater-
9t.
Ground
the
end
of
,IO3O1
feading
to
Pin 7
of
IC3O2.
h.
Adjust
n320
r:ntil eight
tj.ues
the
frequency
of
tone
C
is
read
on ttre frequency counter.
i.
REplace JO3OI on'
tlre pla.
2.
Using an osciLloscope
-
a.
Connect
probe
of
oscilloscope
to
Pin
I of
fC3O1. Set vertj.cal
sensiti.vity to .lv
per
division.
r
b.
Adjusc
R302
so
that
the period
of
the
oscillation
displayed
on
the
oscitrloscope
is
as follows:
toscA
- l/
(8
x
fO)
,
where
fO
is
the
frequency
of
Trone
A
c"
Put
in
enouEh
signal
to quiet
the receiver
and
modulate the
sigmal generator
with just
Tone
A.
Ttre
oscilJ.oscope
will
now
be s'witching
between
a high
and
a low
frequency
oscillation.
d.
tilc\d
connect
the oscilloscope
to pin I of fC302.
you
will
obserne two
different oscillator
frequencies being
switched
at
about
100ros
rate.
e.
one
oscillati.on period
will
vary
with
the
adjustraent
of
R31g.
Adjust
this
period
to -
toscB
=
I/
(8
x fr),
where
f, is
the
frequency
of
Tone
B
f.
The
other
oscillation
period i.s adjusted by R320. Adjust
R320
for
a period
to -
Tosc.
=
L/
(8
x
fa)
,
where
f" is
the
frequency
of
Tone
C
o
(''
= o
DRA\II{
DATE
stzE
A
PART
HUTEER
'I!p'l
4-t
1
q
REV.
A
APPROVEO
/ \.n-, O. /ern_n^
o.AIE
ttnV
t7
DO NOT
SCALE
DWG.
SCALE
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