Connecting The Radio - Uniden UM425 VHF DSC Owner's Manual

Installing the Hardware

Connecting the radio

To operate correctly, your UM425 requires two electrical connections:
• providing it with power from the boat's electrical system
• connecting a VHF-FM marine antenna to the antenna connector
Power supply requirements
Nominal 13.8 VDC power supply with
a negative ground (10.8 VDC to 15.6
VDC).
Power leads should be kept as short
as possible. A direct connection to the
power supply is ideal.
Minimum of #14 AWG copper wire for
extensions up to 6m, 12 AWG wire for
extensions from 6m to 10m, or 10 AWG
wire for extensions from 10 to 18m
13.8V DC
VHF antenna requirements
Male PL-259 connector
50 Ω impedance
Minimum 1.2m, 3 dB rated antenna for
sailboats or 2.4m, 6dB rated antenna for
powerboats
Minimum RG-58 lead-in wire for antenna
leads up to 6m to 10m, RG-8X for an-
tenna leads from 6m to 10m, or RG-8U
for antenna leads from 10m to 18m.
Power
connector
43
Red wire
Black wire
Power
cable
(+)
(-)