Codan Radio MT-3 - Manual (Page 43)

MT-3 ANALOG RADIO SYSTEMS | USER GUIDE
Chapter 5: Radio System Components Page 35
SYSTEM REGULATOR
The SM-3 System Regulator is a plug-in module which provides voltage regulation, system metering
and audio monitoring for an MT-3 radio system. The SM-3 includes the following features:
• High current +9.5 Vdc voltage regulator with an anti-latchup hysteresis circuit.
• Front panel switch selectable meter outputs to check supply voltages, regulated voltages, etc.
• Audio amplifi er and loudspeaker.
• Relay drivers for optional antenna relays.
There are several different models of System Regulators as shown in Figure 5-6. The basic SM-3 is
the same size as a transmitter or receiver module. The System Regulator can also be purchased with
1 or 2 optional antenna relays.
Figure 5-6: System Regulators
Backwards Compatibility
The SM-3 System Regulator is a direct replacement for the SM-3 System Monitor, however, the rotary
switch positions for the front panel test points have been changed.
The simplex mode jumpers to connect the Transmitter PTT OUT signal line to the RX MUTE are now
located on the new motherboard, but the System Regulators still contain the simplex mode jumpers for
backwards compatibility with older motherboards.
2
1
5
4
3
6 7
8
11
10
9
FUNCTION
12
SYSTEM REGULATOR
MADE IN CANADA
VOL METER
+
-
ON
OFF
SPKR
INT
EXT
EXT
SPKR
ANTENNA A ANTENNA B
RX A RX B
TX A TX B
2
1
5
4
3
6 7
8
11
10
9
FUNCTION
12
OFF
VOL
SYSTEM REGULATOR
METER
+
-
MADE IN CANADA
ON
OFF
SPKR
INT
EXT
EXT
SPKR
POWER
ON
VOL
SYSTEM REGULATOR
METER
+
-
MADE IN CANADA
ON
OFF
SPKR
INT
EXT
EXT
SPKR
OFF
POWER
ON
2
1
5
4
3
6 7
8
11
10
9
FUNCTION
12
2
1
5
4
3
6 7
8
11
10
9
FUNCTION
12
SYSTEM REGULATOR
MADE IN CANADA
VOL METER
+
-
ON
OFF
SPKR
INT
EXT
EXT
SPKR
ANTENNA A
RX A
TX A