MFJ-495 Memory Keyer
Instruction Manual
4
©
2001-2009 MFJ Enterprises, Inc.
JMP4
Keyboard Layout
L
Qwerty
*
H
Dvorak
JMP5
RepeatKey
L
Off
*
H
On
Table 3. Keyboard Jumpers.
JMP3
Manual Key
L
Active
Low
H
Active
High
*
Table 2. Manual Key Jumper.
radios with tube finals). Set both jumpers to the “D” positions for direct keying or to the “G”
positions for grid-block keying. If it is set wrong, the transmitter will either not key at all or key
continuously. The factory default * is direct keying output.
•
Manual Key:
An RCA jack providing an input line for manually keyed devices, such as a straight
key or a computer interface. An internal jumper JMP3
configures this jack to accept active-low (for straight key)
or active-high (output from computer software) input.
Set this jumper to the “L” position for active-low input or
to the “H” position for active-high input. If it is set
wrong, the keyer will key continuously. The factory
default * is active-high.
•
Serial Port:
Accepts a standard 9-pin serial plug for connecting the MFJ-495 to a computer for
ASCII file transfers or monitoring your sending on the computer screen. A 9-pin-to-9-pin serial cable
is needed. If your computer has a 25-pin serial port, use a 9-pin-to-25-pin adapter.
To communicate with the MFJ-495, use a terminal program on your computer that is capable of
transferring information in ASCII format. Configure the software for 1200 baud, 8 data bits, 1 stop
bit and no parity; set the flow control to Xon/Xoff.
•
Keyboard:
Accepts most standard AT style keyboards (XT keyboard does not work with the MFJ-
495). The MFJ-551 keyboard is guaranteed to be fully compatible with the keyer and available from
MFJ Enterprises, Inc.
Two jumpers JMP4 and JMP5 inside the unit
configure the keyboard operation. Jumper
JMP4 selects whether a Qwerty or Dvorak
keyboard is used (see Figures 3 and 4 on next
page); place this jumper on the “L” position
for the Qwerty keyboard or on the “H”
position for the Dvorak keyboard. Jumper
JMP5 set the RepeatKey feature that selects
whether or not to repeat a key when it is held
down; place this jumper on the “L” position
to disable RepeatKey or on the “H” position
to enable RepeatKey. The factory defaults * are Qwerty keyboard and RepeatKey off.
•
Key Input:
A ¼-inch stereo phone jack for connecting to a paddle. An iambic or single lever (dual
contact) paddle with a shielded cable should be used. When used with paddles, the dot wire should
be connected to the tip of the plug, the dash wire to the ring, and the ground wire to the shield.
•
Remote Port:
The last port on the back of the unit is for the optional remote control. The remote
control gives you remote access to the keyer menu if the main unit is out of reach. The remote has
the menu and function buttons as well as the paddles connections. The remote connector combines
both the remote functions and the paddle jack so that only one cable from the paddle to the keyer is
needed.
