VXR-5000
VXR-5000 Accessory Connector
The VXR-5000 repeater is provided
with
a
25-pin DB-25F female connector for accesso-
ries.
Use a DB-25M 25-pin male connector to
connect accessories to the repeater. The pins
on
the accessory connector are listed
in
the
table
on
the
previous
page
and
are explained
in detail as follows:
1.
GND
Logic and Power Supply Ground
Connection
Chassis
ground
for all logic levels
and
power
supply
return.
Common
with
pin
13.
Do
not
connect to
pin
7 (A GND), which
is for
grounding
of analog signals only.
2. +13.8 V Power Supply
This
pin
provides
13.8 volts, 1.0A, regu-
lated DC from the repeater power supply.
Use
an
1A fuse to
prevent
damage to the
repeater.
3.
TX
AUDIO
Analog Transmitter Input
(Voice Band
300 -3000 Hz)
Approximately
0.245
Vrms audio
input
on
this
pin
will produce full system devia-
tion
at
1
kHz
(i.e.
with
25
kHz channel
spacing,
± 5-kHz deviation).
Input
imped-
ance is
600
n.
This audio is injected before
transmitter
pre-emphasis
and
limiting
stages,
so
excess signal
input
levels are
clipped.
This
pin
is intended to
be
used as a voice-
band
input
to the repeater for telephone
patch audio, line control panel audio or
community repeater tone panel audio. The
repeater
must
be
in
BASE
mode (pin
13
grounded) for signals
on
this
pin
to be fed
to the transmitter. The absolute level
on
this
pin
can be adjusted
by
VR2001
(LINE
SENSITIVITY control)
and
also
by
S2003,
which provides
10
dB
attenuation, both
on
the CNTL-2 Unit. Use shielded cable to
connect to this pin, connecting the shield to
pin
7 (A GND).
4.
TONE
IN
Analog Transmitter Input
(Sub-Audible Band 67-250 Hz)
Applying a
0.1
Vrms sub-audible tone pro-
,duces 10% of full system deviation. This
input
is
high
impedance (approx.
10
ill),
and
has
a flat response characteristic (re-
peater deviation is constant for a given
1-12
signal level over
the
frequency range of
67-250
Hz). This
pin
is
intended
to
be
used
for
CTCSS
transmission from a commu-
nity repeater tone paneL This
input
is ap-
plied after limiting
and
pre-emphasis,
and
therefore exhibits flat
direct
FM
input
characteristics.
Injecting too
high
a voltage
here
causes
over-deviation of
CTCSS,
degrading
per-
formance. Signals
with
DC content (DCS
or
LTR
data)
should
not
be
connected here,
but
to
pin
15.
If
the
repeater is fitted
with
internal CTCSS,
then
its
output
will
be
pre-
sent
on
this pin. Use shielded cable to con-
nect to this pin, connecting
the
shield to
pin
7 (A GND).
5.
AUDIO
IN
Analog Input
Set S2005
on
the
CNTL-2
Unit
to EXT to
enable
audio
input
to the LINE
OUT
using
this pin. This allows
Rx
audio
to
be
inter-
cepted (at
the
DISC OUT pin, see below),
and
externally processed for special appli-
cations, such as descrambling. The normal
position of
S2005 is INT,
and
in
this case,
AUDIO
IN
signals come from Rx audio.
6.
DISC
OUT
Analog
Output
(Wide-Band 0-3000 Hz)
Received signals
with
full system devia-
tion produce 1
V p-p
audio
at
this pin. The
output
is low impedance,
and
is extracted
before de-emphasis
and
squelch circuitry.
This
pin
should be
used
as
the
Discrimina-
tor Audio Signal required
by
most
com-
munity
repeater
tone
panels
and
telephone
patch
units. Use shielded cable
to connect to this
pin,
and
connect the
shield to
pin
7 (A GND).
7.
A GND Analog Ground
Connect the shields of
any
accessory ana-
log signal lines to this pin. Do
not
connect
this
pin
to
pin
lor
pin
13, as
an
audio
hum
loop
may
result.
8.
S-OUT
S-Meter
Output
A DC voltage proportional to
the
strength
of the signal currently being received (Re-
ceiver Signal Strength) is
output
on
this
pin. This low impedance
output
is gener-
ated
by
the receiver IF sub-system
and
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