
MFJ-1278 & MFJ-1278T Fast-Start Manual
4
Note: Specific wiring diagrams for many Kenwood, ICOM & Yaesu radios are shown at the end
of this Fast-Start manual. Check to see if your radio is listed.
2. Once the cable is properly wired, connect the DIN end to the MFJ-1273 Radio port 1 or Radio
port 2. Connect the other end to the radio.
3. Other connections which you may wish to make are:
CW keying:
Connect a shielded audio cable from the KEYING OUTPUT to the KEY input of your radio.
Use the Grid Block for tube type radio or Direct for solid state radio. Wire the keying cable
as follow:
CW Keying Cable
FSK Connection:
If your HF radio permits FSK Operation, this connection can be made thru the use of the
TTL connector in the rear panel of the MFJ-1278. Only two lines (Pin-8 FSK and Pin-3
ground) are needed in making the FSK connection to your radio. Use the 8-pin IDC connec-
tor supplied with your MFJ-1278 to make the FSK cable. See Diagram below.
Note: The polarity of the FSK signal is defaulted to normal on the MFJ-1278. If your radio
requires you to provide a reverse FSK signal you will need to relocate the shorting jumper
to position 2 & 3 of the JMP 14 header on the MFJ-1278 main board.
FSK Cable
Key paddle:
The cable for the key paddle must be a shielded two conductor plus a shield for ground.
Use a 3.5 mm miniature stereo plug on one end of the cable. The other end of the cable is
wired to the paddle, See figure below to wire your key paddle cable.
CW Key Paddle Cable