©1999 Hamtronics, Inc.; Hilton NY; USA. All rights reserved. Hamtronics is a registered trademark. Revised: 4/29/04
- Page 4 -
these five parameters will be lost. Any
features which were turned on or off
by touch tone command will revert to
your default settings in EPROM
according to the questionnaire choices
you make.
If you wish to power the backup
RAM section of the microcomputer
from a separate battery source, break
the pc trace as indicated by "X" on the
parts location diagram, and solder a
wire for the backup battery to pc pad
E12. The negative lead of the battery
should be connected to ground at J1
or some other suitable place on the
ground plane of the controller board.
The RAM section of the
microcomputer re5Vdc +/-5%
(4.75 to 5.25V). The amount of
current required is approximately 6
mA for the regular (NMOS) MC-6803P
microcomputer.
Since 5V batteries are hard to find,
you can use a 6V battery with a
1N4148 diode in series to drop the
voltage to within the required 5.25V
limit. If you do so, be sure to put a
0.1 µF disc capacitor from the backup
battery pad (E12) to ground to bypass
any high frequency transients which
may be generated by the mi-
crocomputer.
Note that the above backup ar-
rangement is only good for the 6803
(NMOS) version of the microcontroller.
In the 6303 (CMOS) version of the
chip, which is provided if you order
the low standby current option, the
pin on the chip normally used for
RAM backup power is used for
another function instead. Therefore, if
you wish to provide backup power for
the RAM in a repeater with a 6303
microcontroller, it is necessary to do
so for the entire chip instead of just
the RAM section. Because the chip
draws so little current to begin with, it
is no problem to back up the entire
chip with a battery.
To connect a battery to the 6303
chip, disconnect pin 7 of the chip
from the 5V bus and reconnect it to
your backup battery circuit instead.
It is necessary to have an electrolytic
capacitor of about 100 µF from the
power input (pin 7) of the
microcontroller chip to ground.
Autopatch Connections.
The autopatch circuits can be
interfaced directly with any touch tone
telephone line or, where required, can
be interfaced through a protective in-
terface device specified by phone com-
pany. For safety, the autopatch
circuits are electrically isolated from
any source of power on the board by a
transformer and an optocoupler.
For lightning protection, the phone
line should have a protector block
where the phone line enters the build-
ing. This normally is provided by the
phone company as a normal termina-
tion practice.
Monitor Speaker.
To conserve space and allow a low
profile chassis and panel design, the
REP-200 has provision to drive a local
8-ohm speaker but has no built-in
speaker. We do offer a low cost 3 x 5
oval speaker as an option if you want
one, or you may use any speaker you
happen to have with an impedance of
8 ohms or higher. Connect speaker at
push-on terminals J1 and J2.
Auxiliary Receiver.
Push-on terminals J5 and J6
provide COS and audio connections
for an auxiliary receiver, either as a
second input receiver or to cross-link
two repeaters. Touch tone commands
control when the receiver is active in
the repeater.
The aux. receiver may also be used
simply as a control link, a secondary
channel on which to send touch tone
commands for control of the repeater;
in which case, the COS input is not
required. This feature is always
available if an aux. rcvr is connected.
The audio should be taken directly
from the speaker output of the
receiver at a nominal level of 1.5 V p-p
for a signal with full deviation. The
COS signal should be taken from the
squelch circuit of the receiver, at a
point which provides a positive dc
voltage greater than 3V with the
squelch open and close to ground with
the squelch closed. The receiver
ground should be connected to J1 on
the controller board.
Local Touch Tone Pad.
If you don't need to use auxiliary
audio input J6 for an aux. receiver
and you want to have a touch tone
pad for local
operation of the
repeater or for
testing, you can
connect the
output of a pad to
J6 and ground
(J1). Set the out-
put level for about
1.5 V p-p or
advance the output level just past the
point at which the front panel TONES
led illuminates for every digit of the
pad.
Auxiliary Control Circuits.
Two control circuits are provided
for interface with accessories. E7 and
E8 provide open collector outputs
which can sink up to 200 mA of
positive dc current with a voltage up
to 15Vdc. E7 can be turned on and
off by touch tone command. It
normally is used to defeat or enable
the CTCSS (subaudible tone) decoder
accessory (TD-3). It may also be used
to turn any external circuit on and off
if not dedicated to the CTCSS
accessory. E8 is used for tripping the
voice id module option (DVR-2). It
applies a ground pulse to the DVR-2
whenever the controller determines
that it is time to id. E8 may not be
used for any other application.
Alarm Circuit.
There are provisions to connect an
external alarm circuit to the repeater
at push-on terminal J9. This allows
an external circuit to sound an alarm
on the air if activated. The alarm
circuit requires an external switch of
some sort to momentarily pull the
input down to ground to trip the
alarm. If tripped in this way and the
alarm is turned on, a wailing sound
will be transmitted for a period of
time. Thereafter, the courtesy beep is
changed to a short wailing sound
until the alarm circuit is reset by
touch tone command.
The alarm function might be used
to indicate a break in at the building
or cabinet where the repeater is
located. Another use might be to
indicate when battery power is low in
a solar powered installation or when a
standby power system has taken over
in place of a failed main power line
from the power company. Any circuit
which can pull a microprocessor input
low can be used. For instance, a
small signal transistor with an open
collector output is suitable. It only
From SPKR
Output Terminal
From COS
Feedthru Cap.
Ground to Operate
+13.6Vdc
REP-200 #1
REP-200 #2
Relay
COS
COS
AUDIO
AUDIO From SPKR
Output Terminal
From COS
Feedthru Cap.
