Codan Radio MT-3 User Manual

Page 31

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MT-3 ANALOG RADIO SYSTEMS | USER GUIDE

Chapter 4: Analog System Block Diagrams Page 23

Figure 4-2: MT-3 Analog Repeater and/or Base Station Block Diagram

FM RECEIVER

FM TRANSMITTER

CONTROLLER

RF IN

RF OUT

FRONT

END

LOCAL

OSCILLATOR

SQUELCH

CIRCUITRY

IF AMP &

DEMOD

DE-EMPHASIS

AUDIO

PROCESSOR

RF POWER

AMPLIFIER

1 KHz TONE

@ -8.0 dBm

= 60% MAX. MOD.

AUXILIARY

BALANCED

INPUT

1 KHz TONE

@ 60% MAX MOD

= -8.0 dBm

AUXILIARY

BALANCED

OUTPUT

1 KHz TONE

@ 60% MAX MOD

= 0 dBm

1 KHz TONE

@ 0 dBm

= 60% MAX MOD

AUXILIARY

PTT

OPTICAL

ISOLATOR

VOICE BAND

FILTER

CTCSS

DECODER

OPTIONAL

CTCSS

ENCODER

DISC

O/P

RX

MUTE

OPTICAL

ISOLATOR

REPEATER

CONTROL

HANG TIMER

COR

AUXILIARY

COR

OSCILLATOR

TIME OUT

TIMER

AGC PREAMP

& PRE-EMPHASIS

BALANCED

AUDIO

BALANCED

LEVEL

COMPRESSION

MAXIMUM

DEVIATION

SUBTONE

LEVEL

PTT

SUB

TONE 1

I/P

DISTRIBUTION

AMP

AUDIO

LEVEL

SUMMING

AMP

FLAT

LOW

PASS

FILTER

SQUELCH

GATES

DE-EMPHASIS

AUDIO

(TO SYSTEM

REGULATOR SPEAKER)

FLAT

AUDIO

(NO CONNECTION)

DISCRIMINATOR

LPF O/P

(NO CONNECTION)

BALANCED

AUDIO

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