Codan Radio MT-3 - Manual (Page 40)

USER GUIDE | MT-3 ANALOG RADIO SYSTEMS
Chapter 5: Radio System Components Page 32
Antenna Relay Activation
The motherboard on the subrack contains a set of jumpers that are used to activate the optional antenna
relays in the System Regulator module from the Transmitter PTT IN and PTT OUT signal lines. Figure
5-3 shows the location of these jumpers.
JU36 TXA PTT OUT activates Relay A JU37 TXA PTT IN activates Relay A
JU39 TXA PTT OUT activates Relay B JU40 TXA PTT IN activates Relay B
JU42 TXB PTT OUT activates Relay A JU43 TXB PTT IN activates Relay A
JU45 TXB PTT OUT activates Relay B JU46 TXB PTT IN activates Relay B
Simplex Operation
The motherboard on the subrack contains a set of jumpers that are enabled when the radio system is
operated in simplex mode (simplex base station or simplex links). The jumper connects the Transmitter
PTT OUT signal line to the RX MUTE. This jumper will cause the receiver to mute when the transmitter
is keyed.
JU38 TXA PTT OUT mutes RXA JU41 TXA PTT OUT mutes RXB
JU44 TXB PTT OUT mutes RXA JU47 TXB PTT OUT mutes RXB
Figure 5-3: Subrack / Motherboard Rear View
A SIDE
CHANNEL
SELECT JUMPERS
B SIDE
CHANNEL
SELECT JUMPERS
POWER INPUT
+10 to +17 Vdc
+13.8 Vdc NOMINAL
15 AMP FAST
BLOW FUSE
(5604-5GAGC150)
+13.8 Vdc LINE
TRANSIENT SUPPRESSOR
(2007-1N637800) &
REVERSE VOLTAGE DIODE
(2001-MR751000)
+9.5 Vdc LINE
TRANSIENT SUPPRESSOR
(2007-1N637500) &
REVERSE VOLTAGE DIODE
(2001-MR751000)
+9.5 Vdc REGULATED
POWER INPUT /
OUTPUT
(NOT TYPICALLY USED)
CHANNEL SELECT
PULL-UP OR EXTERNAL
CONTROL JUMPERS
ANTENNA RELAY
& RX MUTE
ACTIVATION
JUMPERS
TELEX AND
AUXILIARY
CONNECTORS
CHANNEL SELECT
PULL-UP OR
EXTERNAL
CONTROL
JUMPERS