User Manual
Table Of Contents
- Safety summary
- Preface
- Training information (for FCC approved equipment)
- Introduction
- Operation
- Overview
- General use and navigation
- Power on, speaker volume and antenna tuning
- SSB, AM BROADCAST, DSC or TELEX mode
- Radio settings and ITU channel selection
- Entering Rx and Tx frequencies
- Adjusting RF gain
- Soft-key functions
- Position and MMSI Information
- Channel information always available in the display
- Engagement status
- Speaker devices
- Changing the display colors and dim function
- Squelch on/off (soft key)
- Basic MF/HF radio communication
- Watch function
- DSC calls
- Phone book
- Radiotelex
- Replay function
- Setup
- Service & maintenance
- Glossary
- Index
Chapter 2: Operation
DSC calls 33
2222
Operation
Geographical area calls
When making a DSC area call, you must
enter the position of the ship (x,y) and the
radius of interest r. This information is
transformed to a square with a corner
point (a,b) and the length of its sides, a
and b. Then the DSC message is
transmitted. The illustration on this page
shows the relation between the user
input — the white circle — and the
information transmitted —the grey
square. The center point is the position of
the ship measured in degrees and minutes, whereas the radius of interest is in
nautical miles.
The corner point of the square (a
2
,b
2
) and the length of its sides is given in
degrees. Note that these values are rounded to degrees, and due to the
requirement that the square shall include the entire circle; this will result in a
slightly larger area than defined by the user input.
Attention when close to the poles: If the latitude of the corner point ‘a’ is
transformed to a value greater that 90° then it is set to 90° and the length b
is reduced correspondingly. If the length a is greater than 90° then a is set
to 90°.
(x,y)
r
a
2
,b
2
b
2
a
2
a
1
b
1
b
a