Basic Repeater Controller; Overview; System Configurations; Basic Operation - Motorola CDR500 Programming Manual

Overview

This section describes the system configurations, basic
operation, theory of operation, jumper configurations,
and adjustments for the Basic Repeater Controller.
System Configurations
The Basic Repeater Controller (identical to the
R*I*C*K) connects between two Professional Series
mobile radios to construct an intermittent duty radio
repeater.
Possible configurations for a repeater with the Basic
Repeater Controller are:
• Single Band RT (unidirectional) Repeater
• Crossband RT (unidirectional) Repeater
• Single Band, Bi-directional Repeater
• Crossband, Bi-directional Repeater

Basic Operation

Some of the possible uses for a repeater with the Basic
Repeater Controller include:
• Mobile Repeater
• Mobile "Pac-RT Like" Repeater
• "Suitcase" Repeater
• Portable Site Repeater
• "Mountain Top" (Lookout) Repeater
• Fixed (Rural) Site Repeater
• Fixed (Base) Repeater
• Short Term, Substitute RT Repeater
• Link (RA) Repeater

Theory of Operation

Setup/Knockdown (U1A, Q1, Q2, Q3, Q4,
Q11 and Q12):
U1A is one half of an IC dual type-D flip flop, an
MC14013B. U1A is configured as a data latch. The
CLEAR input, pin 4, is wired low. At power-up, the
PRESET input of U1A, pin 6, is momentarily taken
high via C2 and R9 and causes the "Q" output, pin 1, to
go high and the "not-Q" output, pin 2, to go low. The
"Q" output is connected to pin 1 of J6 and the "not-Q"
output is connected to pin 3 of J6. If JU1 is across pins
March, 2001

Basic Repeater Controller

1 and 2 of J6, then the repeater will be in the "Set-up"
condition at power-up. If JU1 is across pins 2 and 3 of
J6, then the repeater will be in the "Knockdown" con-
dition at power-up.
The electronic switch, Q2/Q3, causes the Set-up/
Knockdown action by applying or removing voltage at
the ignition control, pin 10, of J3-TX. After power-up,
the Setup or Knockdown state may be changed
remotely with a signal from pin 4 of J5-RX or locally
with front panel switch S3. S3 is a momentary contact
switch that is debounced by the Q11/ Q12 latch circuit.
The yellow SET-UP LED, CR3, illuminates to indicate
the Set-up state.
As the Setup/Knockdown circuit goes from the Knock-
down to the Set-up state, Q1 is momentarily turned on
by Q3 via the C1/R2 timing circuit. The push to talk
(PTT) input of the receive radio, pin 3 of J5-RX is pulled
low by Q1 and keys the transmitter. The COR LED,
CR2, will briefly flash during the moment that Q1 is
conducting.
The external alarm input of the receive radio, pin 4 of
J5- RX, is held low by Q4 during the Set-up state. As
the Setup/Knockdown circuit changes from Set-up to
Knockdown, Q4 turns off. The transmitter of the
receive radio will key and send an Emergency Alarm if
that feature has been enabled.

VOX (Q9)

Any audio signal present at pin 1 of J1-RX or pin 11 of
J5-RX causes Q9 to conduct. This in turn will activate
the drop-out delay and push to talk circuitry.

COR Buffer (Q15)

Q15 is a dc amplifier (buffer) for the COR signal from
pin 8, through S2-3, or from pin 14, through S2-2, of J5-
RX. The output of Q15 is switched from a low state
during inactivity of the repeater to a high state with an
active low state for the COR signal.

Audio Gate (Q6 and Q8):

The audio gate, Q8, enables and disables the audio
from the receive radio. The audio input to Q8 is from
pin 1 of J1-RX or pin 11 of J5-RX. The output of Q8 is
applied to pin 11 of J4-ACC and potentiometer, R23.
The output of R23 is applied to S2-5 and S2-6. S2-5 will
route the audio to the flat transmitter audio, pin 5 of J3-
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Section 6
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