Pacific Research Solutions RI-1 - Manual (Page 19)

Pacific Research Solutions RI-1 and PE-1 User Manual
Page 13
SECTION 5 INSTALLATION (PE-1)
The PE-1 (Port Expansion) board adds various features to the
RI-300 controller. The RI-310 controller (Discontinued)
cannot use the PE-1. For additional details, see the schematic
in section 16. These features include:
• 1 full duplexed repeating audio port (input and output)
with level adjustments.
• 2 digital inputs (5V logic). These bits are accessed via S-
Command 45
• 2 digital outputs (open drain). These bits are accessed via
S-Command 46.
To install your PE-1, use the following steps.
1. Turn off power to the repeater and controller.
2. When working on your controller, use procedures to
assure no static discharge occurs through the controller or PE-1.
3. Remove the cover of the RI-300 then remove the radio interface connector mounting studs and 2 screws that hold the
analog board to the chassis.
4. The analog circuit board is the board that has a small transformer. Just behind the radio interface connector, you will find a
black 26-pin socket header. Plug the PE-1 into this header, making sure all pins align. The DB-25 connector on the PE-1
should align in the same direction as the radio interface connector.
5. Carefully re-inspect your installation, making sure that you have all pins correctly aligned.
6. Re-install the analog board and PE-1 into the chassis, installing the 4 mounting studs on the 2 connectors.
7. You are now ready to use your PE-1.
PROPER TECHNIQUES FOR QUALITY REPEATER AUDIO
Obtaining good audio in any repeater is
based on understanding the design of the
equipment. The audio in all frequency
modulation (FM) transmitters or phase
modulation (PM) transmitters has what is
known as audio pre-emphasis. Pre-
emphasis means that with increasing
audio frequency the amount of the
modulation will increase. The reverse is
performed in all FM receivers and is
called de-emphasis. The PE-1 was
designed to operate with both emphasized
and flat audio response from the repeater
receiver and transmitter. This means that
you can bypass the de-emphasis and/or
pre-emphasis stage in the radio when
possible. This leaves all of the emphasis filtering in the user’s radio. The PE-1 will interface to emphasis audio when needed.
The PE-1 controller does include a low pass filter that rolls off the very high audio frequency content to prevent adjacent
channel splatter. It is not advisable to drive the microphone input on the transmitters. Most transmitters have significant audio
shaping, compensating for the microphone response and other characteristics.
Besides audio frequency response, you should consider the audio amplitude levels to and from the controller. If the levels to
and from the repeater are small, it may be valuable to use shielded cable. We recommend shielded cables at all times. Use
large signal levels whenever possible. On the other hand, do not let the audio signal get large enough where clipping occurs in
any stage of the controller, the receiver, or the transmitter. See section 6 for more details on adjusting the audio levels in the
controller. Consider and practice the above and you will have repeater audio that you and your repeater users will be proud of.
Audio Input (RX)
Audio-Ground
Digital-Ground
PTT (Open Drain)
Audio Output (TX)
Analog In
Radio Data Out
PE-1 Interface Connector
13 12 11 10 9 8 7 6 5 4 3 2 1
14 16 15 18 17 19 24 20 21 22 23 25
5Volts@25mA Out
Radio Data In
Radio Pwr Switch
Radio Pwr Detect
Sypply-Ground
User In 2
User In 1
SLE
SCK SDA
RS-232 TXD
RS-232 RXD
RS-232 CTS
RS-232 RTS
User Out 1 (Open Drain)
User Out 2 (Open Drain)
TSQ (CTCSS)
NSQ (COS)
Transmitter
Modulator In
Gnd
TX Key (PTT)
Supply Return
Discriminator Out
Gnd
Receiver
REPEATER/RADIO
RX-Audio In (2)
Audio Ground (15)
Power Ground (14)
TX-Audio Out (3)
Push To Talk (4)
PE-1 Port Expansion
Repeater/Radio Connections
SHIELD
TSQ In (7) TSQ (CTCSS)
NSQ In (6) NSQ (COS)