MST70 Owner’s Manual Page 7
GND
SEK
ELECTRICAL WIRING
DC Connections
Caution:
The MST70 is designed for vessels with a 12 Volt negative ground
electrical system only!
Referring to the wiring diagram:
1. Connect the Red wire directly to the positive terminal of the vessel’s battery,
or to a point which has +12 Volts available at all times. This lead maintains
the memories within the MST70 and is the main power source for the unit.
2. Connect the Orange wire to the vessel’s +12V supply via an appropriate
isolating switch or circuit breaker. This lead turns the radio ON and OFF.
Alternatively, this wire can be connected directly to the battery’s positive
terminal and the MST70 switched ON and OFF using it’s own controls.
3. Connect the Black lead labelled
‘GROUND’
to the battery’s negative
terminal or to the common negative bus in the electrical system.
Important:
Your MST70 is able to maintain it’s memories when it is switched
off by drawing power directly from your battery via the Red lead. Although the
memory backup current is very small (about 7 mA) it may eventually discharge
your battery if left connected indefinitely. The time taken to completely discharge
External Aux. Switch
(Optional)
Optional Master
Switch
Antenna
RED
ORANGE
10 AMP
1 AMP
BLACK
MST70
