Epson Multi-mode Data Controller MFJ-1278B User Manual

Page 62

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MFJ-1278B MULTI-MODE BASIC OPERATION

information how the CON and STA leds react to incoming signals please refer to the chart on
Page 30 of this chapter..

Monitoring AMTOR ARQ requests

AMTOR ARQ requests monitored while the MFJ-1278B in PACTOR mode. If the
controller detects your selcall in an AMTOR ARQ request packet, the controller will switch
to AMTOR and try to establish the link. This feature allows someone who doesn't have
PACTOR capability to connect to you in AMTOR mode. Upon termination of the link, the
MFJ-1278B will switch back to the PACTOR. The a_cmd: is active when the MFJ-1278B
switches to the AMTOR operation. When the MFJ-1278B switches back to the PACTOR,
you will see the p_cmd: prompt again.

Exiting PACTOR Mode

To exit the PACTOR mode, please type CTRL-C and the p_cmd: prompt will appear. Once
the p_cmd: prompt is on the computer screen, type the following:

EXIT <ENTER>

the MFJ-1278B will respond with the standard cmd: prompt. Once back at the cmd: prompt
you can go to any other mode by use of the MODE command as discussed earlier in this
instruction.

Operating Hints

Threshold Control Setting

Adjustment of the Threshold control on the MFJ-1278B is critical during PACTOR operations.
Adjust the Threshold control until the DCD lights with each received packet and goes out when
not receiving. If the threshold control is improperly adjust, communications will not be good.
This could result in the inability to make a contact or monitor a PACTOR conversation.

TXDELAY (TXD)

Timing in PACTOR is more critical than any other mode. This is where the TXDELAY or
TXD command comes into play. The TXDELAY command is one of the more critical
parameters. If you are having problems connecting, try adjusting TXD a little higher than the
default value of 2. This is especially good practice on the lower frequency bands such as 80
meters. A typical setting for 80 meters may be 4 or 6. The setting of TXDELAY is also
dependent on the time required for the radio to switch between transmit and receive.

NO200

If you turn the parameter NO200 to ON, the MFJ-1278B will stay in 100 baud. For noisy band
conditions setting NO200 to ON may get your data through quicker. This is because if the
controller switches to 200 baud you may have more retries on a noisy channel. It's better to

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