Instruction Manual
39
E03912 Issue 2.0
The RD68 has five electrical connections – the handset/fistmike
socket is on the front panel below the LCD display (Fig 4.4A).
The other four are situated on the back of the case: the antenna
socket is on the left (Fig 4.4B); DC power is supplied to the set
via a two-core flying lead (Fig 4.4C); the NMEA input connec-
tions (Fig 4.4D) allow a GPS to be interfaced, below which is a
3.5 mm jack socket for an optional extension speaker (Fig 4.4E)
– this is covered by a weather plug when not in use.
The VHF requires a 12V DC supply to operate and is supplied
with a power lead which incorporates an in-line 7.5 Amp fuse.
This lead should be connected to the vessel’s power supply,
keeping the cable runs as short as possible. Although the radio
draws very little current when receiving, a heavier current is
drawn when transmitting, which may result in a voltage drop if
long cable runs of inadequate core diameter are used. If the sup-
plied power lead is not long enough, an extension of up to 3 m
(10 ft) can be made using at least 2.5 mm
2
(13 AWG) wire.
The red wire is positive and black is negative. If polarity is
accidentally reversed, the set is protected, but the fuse will blow.
Ensure that it is replaced with a fuse of the correct 7.5Amp rat-
ing. The radio is designed to be easily removable for storage or
security, so leave an adequate length of cable to ease disconnec-
tion. The flying lead from the rear of the radio can then be
plugged into the power supply lead. Note, that the configuration
of the plug prevents incorrect connection.
A - Handset / Fistmike
B - Antenna
C - 12V DC
E - Extension
speaker
Fig 4.4 - External connections
D - NMEA
