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MFJ-1278B MULTI-MODE BASIC OPERATION
To enter the converse mode type:
K
This will take the MFJ-1278B out of the command mode and into converse mode. When the
MFJ-1278B enters converse mode, the STA will illuminate. Also after entry into converse
mode the MFJ-1278B is in receive mode. You can enter transmit mode by typing
CONTROL-T. To re-enter receive mode type a CONTROL-R The command CONTROL-
C will return you to the command mode, where you will get the cmd: prompt on your screen.
Use lower side band, LSB unless you have an RTTY position on your rig. Tune your radio
until the 10th or 11th segments on the tuning indicator light during receive. Ensure that the
yellow DCD led is illuminated also during receive. It is possible to tune to the center of the
bar graph, and not have the DCD led lit. If the DCD led does not light, then check the setting
of the Threshold control on the front panel. The DCD led needs to be lit for reception. Some
bouncing of the LED is normal, since any audio other than the signal (QRM/QRN) will also
affect how it responds. From the converse mode you should now see text being printed on
the screen as it is heard. Contacts usually take place on a one-way at a time basis. So one
side will transmit and the other will receive, and then the sides are reversed.
To allow the MFJ-1278B to transmit RTTY or ASCII, type:
CTRL-T
while in converse mode to key the PTT on the radio. The green PTT light should light and
you should see power on your wattmeter. All keystrokes are now sent out over the air.
Alpha-numeric (numbers and upper/lowercase letters) characters are the only kind of
keystrokes accepted. Some punctuation is allowed. When the transmission standards were
set up, only mechanical typewriters (tele- type) were used and these were the only keys in
use. Most other characters such as Greek and graphics are usually translated wrong, and
you'll see the other guy's 'mistakes' when he types one of the characters. To go back to the
receive mode, type CTRL-R in converse mode to unkey the radio, and you will return to the
receive mode. This will start the transmit/receive cycle over.
Commercial RTTY Reception
Commercial RTTY presents a special problem for amateurs and short wave listeners. Several
conditions must be met before you can get a decent printout. You have to locate the
frequency of a particular station, get the schedule right, pick the sideband, set the baud rate,
set the frequency shift, and finally, unencrypt the text.
You can receive many of these stations using the 425 shift, 50 baud, and lower sideband
during the daylight hours. For this setup use MODE VB,50. Some military frequencies are
unencoded, as well as some of the UPI broadcasts. A good source of frequencies is Popular
Communications and Monitoring Times magazines.