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MFJ-1278B MULTI-MODE BASIC OPERATION
BAUDOT RTTY & ASCII OPERATION
The user can configure the MFJ-1278B RTTY/ASCII modems to copy several shifts,
including 170, 425, and 850 Hz shifts. The user can use the MODE command to configure
the RTTY/ASCII modems for the different shifts. The MFJ-1278B will transmit and receive
RTTY and ASCII at speeds of 45, 50, 57, 75, 100, 110, 150, 200, and 300 baud.
The MFJ-1278B transmit and receive WIDE and NARROW shift RTTY or ASCII. Wide
shift RTTY/ASCII operates on standard tone pairs of 2125 Hz for MARK and 2975 Hz for
SPACE. The frequency shift for WIDE shift RTTY/ASCII is 850 Hz. Narrow shift
RTTY/ASCII operates on standard tone pairs of 2125 Hz for MARK and 2295 Hz for
SPACE. The frequency shift for NARROW shift RTTY/ASCII is 170 Hz.
In the RTTY mode, the MFJ-1278B will receive and transmit both the American Western
Union and the internationally recognized CCITT character set. In ASCII mode MFJ-1278B
will transmit and receive 7 bit ASCII code.
Note that the MFJ-1278B provides you with the option to select Low Tone RTTY/ASCII.
Low Tone RTTY/ASCII uses standard tones of 1275 Hz for MARK and 1445 Hz for
SPACE. The frequency shift for Low Tone RTTY/ASCII is 170 Hz. You can select Low
Tone RTTY/ASCII through the "V" modem. The Low Tone pairs are the standard used in
Europe for RTTY and ASCII operations. Please refer to APPENDIX H on how to select the
Low Tone pairs.
The MFJ-1278B can transmit or receive RTTY or ASCII by using inverted tone pairs. The
RXINVERT and TXINVERT commands allow inverting of the tone pairs, in the RTTY or
ASCII modes. When operating in the inverted mode, the tone pairs are MARK for the high
tone, and SPACE for the low tone.
The MFJ-1278B also allows you to transmit from any one of the ten memory buffers when in
one of the asynchronous modes. Memory buffer programming and use are the same as for
CW operation.
Setting Up for ASCII and RTTY Operation
From command mode, you can set the MFJ-1278B into the desired RTTY or ASCII mode by
using the MODE command. Type:
MODE ## <ENTER>
Where ## is the two letter code for the desired RTTY or ASCII mode.
Code designations for RTTY and ASCII modes are as follows:
VHF RTTY VB
HF RTTY
HB