MFJ-1224 Instruction Manual
RTTY/CW Computer Interface
12
CALIBRATION OF 170Hz SHIFT
1. Put the computer into RTTY RECEIVE. For Hamsoft
on the VIC-20
.
2. Connect the frequency counter in the same manner as setting the MARK Frequency.
3. The counter should read 2295Hz.
4. If the counter doesn't read 2295Hz, then adjust VR3 (See Fig 4) for a reading of 2295
(+ 2Hz).
CALIBRATION OF THE 850Hz SHIFT
1. Set the MFJ-1224 front panel switches for 850Hz shift.
2. Connect a frequency counter as in Calibration of the MARK Frequencies.
3. The frequency counter should read 2975Hz.
4. If the counter doesn't read 2975Hz, adjust VR4 (See Fig. 4) for a reading of 2975Hz
(+ 2Hz).
SOFTWARE CONSIDERATIONS
DIP SWITCH
There is an eight switch DIP package on the PC board. These switches are used to
configure the inputs and outputs of the GENERAL PURPOSE CONNECTOR to work
correctly with your computer and software. The following chart illustrates functions of
each switch.
SWITCH
POSITION
FUNCTION
SIGNAL AT PIN
1
ON
CW KEY
LOW-KEY
1
OFF
CW KEY
HIGH-KEY
2
ON
CW ID KEY
HIGH-CW-SHIFT
2
OFF
CW ID TONE
LOW-CW-SHIFT
3
ON
KANTRONICS PTT
N/A
3
OFF
GENERAL PTT
N/A
4
ON
RTTY INPUT
LOW MARK
4
OFF
RTTY INPUT
HIGH MARK
