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MFJ-1278B MULTI-MODE BASIC OPERATION
Monitoring Mode A, "ARQ"
The LISTEN command is useful for monitoring other people's ARQ contacts. To use, tune
in a Mode A signal and type LISTEN. Both the CON and STA leds will light until the
station is synchronized, at which time the MFJ-1278B will start to receive.
Since the monitoring of MODE A signals is not error protected, you may see occasional
errors. How well the MFJ-1278B receives Mode A signals depends on the quality of the
signal. The quality of Mode A signals depends on how well the MFJ-1278B hears both sides
of the QSO. Band conditions also have an effect on Mode A signal quality. The LISTEN
mode is most useful for allowing amateurs to continue to self police their bands.
Mode B "FEC"
Mode B FEC is a "One transmitter, many receivers" mode. Unlike packet or ARQ, FEC
does not establish a one-on-one link setup, nor does it have a re-transmission feature. Mode
B, FEC is mainly used for calling CQ. The amtor operator would first call CQ in Mode B,
then wait for a call from another operator in Mode A.
Setting up for Mode B "FEC"
Setup for Mode B FEC is the same as ARQ, although a selective call is not required.
Mode B "FEC" Operations
To receive Mode B FEC, tune the FEC signal in so the center segments on the MFJ-1278B
tuning indicator light. When the MFJ-1278B detects the synchronization pattern, either the
CON or STA led will light. The exact point in the transmission to which you tuned to,
determines if the CON or STA led lights. When either the CON or STA led lights the
received data will begin to display on the terminal screen.
Use Mode B FEC, for calling CQ, operating in round tables, and for transmitting bulletins to
more than one station at a time. To transmit MODE B FEC, type FEC followed by a
carriage return, at which time your transmitter will key up. Now type CONVERSE or K to
enter the data mode and you're on the air with FEC. Anything entered from the keyboard
once in the data mode is transmitted.
When you're done transmitting, return to the AMTOR command mode, a_cmd: with CTRL-
C. In order to release the transmitter type R or QRT followed by a carriage return. At this
point again the MFJ-1278B will automatically attempt to synchronize to any mode B signal it
hears.
Mode S "SELCALL"
Mode S is exactly like Mode B, EXCEPT that the broadcasting station can select one or a
group of stations to receive the transmission. The
SRXALL
command in the AMTOR