MFJ-484 GRANDMASTER MEMORY KEYER
The MFJ-484 is a highly sophisticated memory keyer using 15 state-of-the-art Integrated Circuits
and 4 Random Access Memories which are standards of the industry. It provides the best in per-
formance and the ultimate in flexibility. To insure full benefit of this memory keyer, please read the
instructions before operating.
CONTROL FUNCTIONS
1. SPEED CONTROL is variable from 8 to 50 wpm. Pull this control out to record.
2. WEIGHT CONTROL when turned fully counter clockwise, dot-dash-space ratio is a perfect
1:3:1. Turn clockwise to increase dot and dash lengths. Pull this control out to combine A and
B memory addresses.
3. TONE CONTROL for the desired side tone pitch. Pull this control out to TUNE (keys your
transmitter continuously).
4. VOLUME CONTROL to adjust the loudness of the internal speaker. Turn this control fully
counter clockwise to turn off the memory keyer. All messages stored in memory are erased
when this control is turned off. Keep power on to maintain memory.
5. DELAY CONTROL Pull this control out to turn on the time DELAY. This will cause the memory
keyer to automatically repeat your message. The time delay between repeating your message
is variable from 0 to 2 minutes. Automatic repeating will continue indefinitely until the reset but-
ton is pressed, the keyer paddle is tapped, or the time delay control is pushed in. When this
control is turned fully counter clockwise, there is no time delay. It will instantly repeat your mes-
sage. To increase the time delay before your message restarts, turn the DELAY CONTROL
clockwise.
6. MEMORY SELECT Positions 1, 2, 3 are each divided into MEMORY ADDRESS A, B, C and
D. Each MEMORY ADDRESS can record up to 25 characters. Record messages into MEMO-
RY ADDRESS A, B, C and D for each MEMORY SELECT position 1, 2, 3. You can record up
to twelve 25 character messages. Pull out the WEIGHT CONTROL to combine A and B on
memory select 1, 2 or 3. MEMORY SELECT position K combines A, B, C and D automatically
for recording very long messages. Pressing A, B, C and D gives 100, 75, 50 or 25 character re-
spectively. When using MEMORY SELECT K the memory will always begin at A in the repeat
mode.
7. MEMORY ADDRESS For push buttons A, B, C and D are used to directly address the memo-
ry. Press a MEMORY ADDRESS button to start a message or to records a message.
8. RESET is used to stop memory from operating. When a recorded message is being sent,
memory can be stopped by pressing the reset button or by tapping the keyer paddle. Memory
operation can be interrupted by pressing another MEMORY ADDRESS without pressing RE-
SET button first.
9. LED INDICATORS A, B, C and D light to show which memory address is in operation. The
fifth LED (time delay) will light during the time delay period.
10. MEMORY SAVER
An internal 9 volt battery (not included, alkaline type recommended)
switches in automatically when a 110 volt AC power failure occurs. This allows all messages to
be retained. A battery clip and holder are provided for installation of a 9 volt alkaline battery. If
the side tone is not used, The MEMORY SAVER has an operation time of approximately three
hours. If longer storage time is needed an external battery (12–15 VDC) may be connected to
the battery jack on the memory keyer. MEMORY SAVER is also turned off when the VOLUME
CONTROL is turned off.
INSTALLATION
1. To install the memory save battery, remove the two screws near the rear top. Slide the cover
toward the back and remove. Connect a 9 volt battery to the battery snap then insert the bat-
tery into the battery holder. A 9 volt alkaline battery should be used. When the memory save
battery is not used cover the battery snap with the plastic tubing supplied to prevent shorting.
