Epson Multi-mode Data Controller MFJ-1278B - Manual (Page 100)

MFJ-1278B MULTI-MODE BASIC OPERATION
letter identifies the type of message. Refer to the following explanation of the NAVMSG
command for the different types of messages that are identified by this second letter.
The NAVMSG and NAVSTN commands allow you to choose both the types of messages
you receive and the stations you receive. The other command that applies is the NAVTEX
command.
To enter NAVTEX mode, you must first enter AMTOR mode by typing:
MODE AM <ENTER>
The MFJ-1278B will respond with the a_cmd: prompt. From the a_cmd: prompt type:
NAVTEX ON <ENTER>
The MFJ-1278B will display the Navtex command prompt, n_cmd:, indicating that it is
ready to monitor any Navtex messages. Once in the Navtex mode, tune your radio to the
Navtex frequency of 518 KHz.
To receive NAVTEX, the MFJ-1278B must first receive the ZCZC start message, followed
by the four character preamble described above. If this is not received intact, the message
will not be received. At the end of the message, NNNN will be received and the MFJ-1278B
will stop receiving the Navtex message.
The MFJ-1278B will remember the last 200 four character preambles received with less than
1/8 of its characters received in error. The MFJ-1278B will not reprint any of these messages
when they are re-transmitted from that Navtex station. If you exit the "a_cmd:" command
prompt, the preamble memory is erased.
Emergency messages are numbered 00 and will always be printed regardless of whether they
have already been received.
To prevent your MFJ-1278B from receiving certain Navtex stations, just type NAVSTN
XXXXXXXXXXXXX where each X is the identifying letter of the station you want to
receive. Your list of stations to receive may contain up to 26 letters, each representing a
station.
For example, if you want to receive only stations A, C and P, then you type NAVSTN ACP.
Only signals from these three stations will be received by your MFJ-1278B.
If you want to prevent certain stations from being received, leave then off the list. Then,
those stations will not be received while others within the receiving area will.
You may also type NAVSTN ALL, the Default value, to receive all Navtex stations.