ICS Nav6plus, Руководство пользователя

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NAV6 plus NAVTEX System User Guide
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APPENDIX IV.
APPENDIX IV. APPENDIX IV.
APPENDIX IV. OPTIMISING NAVTEX RECEPTION.
OPTIMISING NAVTEX RECEPTION. OPTIMISING NAVTEX RECEPTION.
OPTIMISING NAVTEX RECEPTION.
When sailing within a published NAVTEX service area, reception
coverage can extend to as much as 200 - 300 nautical miles. If the
NAVTEX signal has to cross land to any significant extent, attenuation
may occur and this can reduce the reception range to as little as 50
miles. Range can increase significantly at night, it can sometimes extend
to as much as 1000 miles. Some NAVTEX stations reduce transmitter
power at night to avoid overlap of signals into other sea areas.
Background electrical noise in a marina, the presence of high cliffs and
the masts of surrounding vessels can all contribute to poorer NAVTEX
reception when in harbour, rather than at sea.
To ensure you get the best reception possible, always mount the
NAVTEX sensor in a location that is free of other electrical equipment.
Take care to avoid locations that are close to wind generators, battery
charges, shore power transformers and any associated electrical power
wiring. If you have any doubt regarding the suitability of a proposed
sensor location, first make a temporary ‘test’ installation to confirm that
the reception performance meets your requirement before committing
time and effect to a full sensor installation that you may later have to
change.
Checking the quality of NAVTEX Reception
Checking the quality of NAVTEX Reception Checking the quality of NAVTEX Reception
Checking the quality of NAVTEX Reception
The NAV6 NAVTEX ‘monitor page’, shows live reception diagnostic
information, this can be helpful when proving a system is receiving
correctly and can assist in evaluating a proposed sensor site.
The monitor page is access by selecting; SETUP MODE, NAVTEX
VIEW, MONITOR PAGE.
The information shown on the monitor page is totally independent of
normal operation, station and message type selection filters. As soon as
live NAVTEX reception is detected, received information will start to flow
across the display in real time. Non-printing, transmitter-idle and phasing
characters are displayed as well as actual message text.
The top half of the monitor screen is dedicated to displaying 490kHz
reception data, the lower half 518kHz. The current reception error rate is
displayed as a percentage of errors alongside the associated bar graph.