Advertisement
8.,
Unit
Testing
l.
With
earrier
Reset Option
-
a.
Set
alert,/nonitor srritch i:rto spnitor position.
'
b.
With no
RE
sigmal
applied, adjust
squelch
f,or desired
squelching actj.on.
c.
Retutrr
alert/rcnitor
switch
back
to
the
alert
position.
d.
.1pply
enough RF
signal to qrrlet the receiver
and
signal
the
unit
w"ith
the proper
txro-tone
sequence.
e.
The
sqgelch should
open
allorring the
listener to
hear
the
renainder
of
the
second
tone's dr:ration
and
the
message
.
lanp
should
flash
at
a high rate.
f. lurn off
applied
RF
siFal
so
that
the radio
goes
i-nto
the
squelched
urode. the
decoder
is
now
reset
and
no other
signal other
than the proper tno-tone
sequence
will
open
the
squelch.
9.
The
MSG
LED
should
renain flashing
until
the reset
switch
is
rcved
into
the reset position.
2. lrith
Ti-ae-o|rt Res€t Option
-
a.
TuJrt
up
RF
signal
enough
to quiet
the receiver.
b.
Modulate
the signal
generator
with the
proper tao-tone
sequence.
c.
The
squelch should open,
allowing the receiver
to
operate
nomally
for
a
given geriod
of time.
This
time
period
can be adjusted
by
vary!.ng
R293.
The
t{SG LED
will
be
flashing
at
a \rery
fast rate
and
wj-ll
remain
fla$ring
when
the
decoder has been
reset.
d.
[he
t4SG
tED can be
reset
by pushing ttre
reset
switch
to
the
right.
F.
Acceptable Performance Lirnits
Frequensy
Range
*
2Og
-
3,906
IIz
Frequency Cor:nter
will read
1,664.-
31
,24g.
Decoder
Sensitivity
12dB
Sinad IOO* detect
6dB
Sinad
75r detect
Audio
fnput
at
Pin 5
of
IC303
must
be
1.3vpp
or
greater
rFor tone
frequencies lo\der than
3C0
IIz
it
uray
be necessary
tq
change C301,
C316
or
C317
respectively
to
820pf.for tliose
oscillators
below
30O
ilz
only"
PROPER
TONE
SEQUENCE
Tone
A
Tone B
or
C
0iAvIr{
OAT€
stzE
A
PART
I{UHEER
TP14-2I9
REV.
.\
APPRov€o
.t-,',- A- 2: -
oal6
1:
ii
p,ht
DO NOT
SCALE
OWG.
SCALE
4
SH€ET
+
Advertisement
