The SITOR-FEC mode is used in broadcast applications where a return channel is not required or unavailable. Two sub-modes are in use: General broadcasting to a number of stations and selective addressing of only one station.
|
Parameter |
Value |
|
Frequency range |
HF |
|
Operation modes |
FSK, Broadcast/Simplex FEC |
|
Modulation |
FSK |
|
Symbol rate |
100.0 Bd |
|
Receiver settings |
DATA, CW, LSB or USB |
|
Input format(s) |
AF, IF |
SITOR-FEC transmissions are used in maritime radio communication to distribute traffic lists, news, safety and weather information. Amateurs also use the FEC mode for calls to all (CQ calls).
The selective FEC is used when the receiving station must operate under "radio silence" conditions and hence cannot transmit.
In most cases SITOR-FEC transmissions uses a rate of 100 Baud using the standard shift of 170 Hz.
Each character is transmitted twice with an interval of 35 bits. In the case of error-free reception of both characters, the character is displayed on the screen. The underscore (_) character is displayed if both characters are received in error.