English VHF NX2000
40
Fig D
The NX2000 requires a 12v DC supply to operate. This lead should be connected to the
vessel’s power supply (the red wire is positive, black is negative), and the cable kept 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 very long cables
are used of inadequate core diameter. If the supplied power lead is not long enough, an
extension of up to 3m(10 ft) can be made using at least 2.5mm (13AWG) wire.
The chassis of the NX2000 is not connected to either supply rail. This allows a direct
connection to the ship’s earth connection for voltage and RF interface protection. The
red wire is positive and black is negative. If polarity is accidentally reversed, the set will
not operate.
The antenna is connected to the NX2000 using a standard PL259 type connector as
fitted to most marine antenna. If fitted to an existing antenna, check that the contacts
are not corroded before connecting, as this will affect the quality of the signal, Ensure
that the retaining collar of the antenna plug is securely tightened to prevent accidental
disconnection.
15.2 Antenna Installation Recommendations
The most important factor in the performance of the NX2000 will be the quality and
positioning of the antenna. Most recorded problems with VHF Radios are related to
poor antenna sighting, faulty cabling, poor quality cable joints and low voltage supply.
Even the best performing Radio cannot compensate for these factors. If replacing an
existing installation using the same antenna, it is important that these factors are
checked when installing the Radio.
As the range of VHF signals are governed by line of sight, the antenna should be
placed as high as possible, while remaining clear of any metallic objects that could
influence the resonance of the antenna.
