MFJ MFJ-121B User Manual

MFJ-l2lBDua|RadioContro|ledC|ockwithAuto.Back|ight
Theunitworksonreceivingthetimeradiosignal.Thetimesignalisgenerated
UV
,f*
US
Atomic
Ctoct
itrictr
is
located
in Colorado.
The
Atomic
Clock
is
op"*r"o
by
the
US
Depafiment
of
commerce's
Nationai
Institute
of
standards
"ia
i*n*f"ry.
To
enhance
eood
receotion'
avoid
phci4g
{he
unit
n9ar
ielevision
seri
;;GiTrleces
cgmouten.
or
etectric
devices
as
tnae
GGilEiFill
ioicrfcre
the
receotion
of
tedio
signal'
The
dual
radio
controlled
wall clock
features:
I
Dual
clock:
two
clocks
in one
unit,
each can
be
operated
independently
lGMTtimezonewithDavLiehtSavingTime(DST)selectabletooFF
r
Radio
confiolled
(ww'\rB)
with automatic
daylight
saving
time
adjustment
I
Auto-Backlight.
in"
aisptay
will be
lighted
for
8 hours
continuously
after
this
function
is
activated.
r
Battery-lowindicator,
I
Big
display
sho\r6
tune
in hour,
minute,
second
r
nn4l*.display
format
user selectable.
I
Mounted
on
wall
or
standing
on
desktop
(with
built-in
easel
stand).
When the
battery
power
(for
the
auto-backlight)
is
low,
the
light
will become
dim
or there
witi Ue
no
backlight.
If
this
is
the case,
please
replace
the
batteries
(for
the
auto-backlight)
with
new
ones.
Time
radio
sisnal
recePtion
ffie
the
time
sigrral
automatically,
place the
AUTO-
RECEPTION
SWITCH
at
"ON"
position
IMPORTANT
NOTE:
If
the
AUTo-RECEPTION
SWITCH
is
place
at
"oFF" position,
the
unit
will
not start
to receive
time
sigral
automatically
(manual
reccption
is
still
available).
The
unit
will
search
for
time radio
signals
automatically
after
baJtertes
are
iniiul.O,
if the
AUTO-RECEPTION
SwnCg
is
placed
ut
:9N"
position
Uri.i.
Uln.ry
installation.
The
radio signal
mark
on
the right
of
the upper
and
tower
Oisptay
will
start
pulsing
to show
the
receiving
status'
lf time
signal
ls
received
inddecoded
suicessfulty,
the
time
will
be
updated
automatically'
Remark:
During
signal
reception,
if
the
time
is set
manually,
reception
will
be terminated.
Since
the
unit
works on
receiving
the
time
radio signal,
there
may
be
locations
that the
sigral
is
weak
and
lannot
be
properly received.
Under
such
circumstancE,
the
radio sigrral
mark
will
disappear
to
indicate
reception
failed'
Try
to rotate
the
unit
or
plice
it
in other
to941o1
to
achieve
better
reception
and
re-start
reception
by
pressing the sET
BUTTON
once.
If
frnally,
radio
signal
camot
be
reieived,iime
of
Uottr
Clock
1
and clock
2
should
be
set
manually'
IMPORTANT
NOTE:
Press
the
sET
BUTTON
of
CONTROL
PANEL
I
will only
start
the
manual
reception
of Clock
l. To
start
the
manual
reception,of
!gt9]ff
t *d
'
Clock
2,
please
press the SET
BUTION
at both
CONTROL
PANEL
I and
CONTROL
PANEL
2.
Select
the anoroPriate
til4e
zone
ffi
at CONTROL
PANEL
I
and
CONTROL
PANEL
2 to select
the
appropriate
time
zone
for
Clock
I
and
Clock
2
respectively
(Clock
I
and bto-ct
Z can be
set
to a
different
time
zone).
otherwise
the
unit may
not be
showing
the
conect
time
If
your
desire
time
zone
is
not on
the
dispiay
map
you
must
set the
time
manually.
See
"manual
time setting"
instruction
below.
Davlisht
savine
time
adiustment
ffiing
time
automatically
after
successful
time
signal
reception,
if t6"
fjSf
ON
OFF
SW1TCH
is
placed at
"ON'.position.
When the
time
is shown
as
daylight
saving
time,
the daylight
saving
time
mark
will
be shown.
To deactivate
this
function,
place
the
DsT
ON
OFF
SWiTcH
at "oFF"
position,
and the
unit
will not be
adjusted
to
daylight
saving
time
automatically'
if
you
selected
the
GMT
time
zone
the
DST Switch
should
be
placed
at
OFF.
Note:
Please
place
ttre
DST
ON
OFF
SWITCH
at both
CoNTROL
PANEL
I
and
CONTROL
PANEL
2
at
the
appropriate
position.
Select
the
l2-Hour
snd
24-Hour
disolav
fo.fr,nat.
L
I and
CONTROL
PANEL
2 to select
the display
format
of
the
time
(clock
I
and
clock
2 can
be
set
to
a
different
display
format).
Set
the time
manuallv
To
set the
ttme
of
Clock I
;
press
and
hold
the sET
BUTTON
(at
CONTROL
PANEL
l) for
about
2
seconds
The
time digit
wrll
start
to flash
Press the
A
or
V
BUTTON
to set
the
tune.
Each
push
of
the
A
or
V
BUTION
wrll advance
the minute
by
one,
while the
hour
will be
updated
when
,.00"
minute
is
run
through. Press
and
hold
the
A
or
v
BUTTON
and
the
digits
will fast
advance.
After
setting,
press the SET
BUTTON
once
to
end
the setting
mode,
or
the unlt
will
quit the sening
mode
automatically
after
the
unit
is
idle
for
about
30
seconds.
To
set the
nme of
Clock
2:
Press
and
hold the
sET
BUTION
(at
CONTROL
PANEL
2)
for
about
2
seconds.
The
time
digit
will
start
to flash.
The setting
metirod
is the same
as
Clock
l.
The Auto-Backlieht
when the
Autosacklight
function
is activated,
the
display
will
be
lighted
fbr
E
hours
continuously.
TJ set
the
starting
time
of activating
the
Auto-Backlight,
place the ALryO
LIGHT
SWITCH
"i
"SET"
position.
The
hour
and
minute
digits
at Clock
I
will
flash.
priss
the
A
or
V
BUT1ON
to set
the starting
time.
Each
push of
the
A or
V
BUTTON
will advance
the minute
by
one,
while ttre
hour
will
be
updated
when
"00"
minute
is
run through.
Press and
hold
the
A
or
V BUTTON
and the
digits
will fast advance.
After setting,
place
the
Alrro
LIGHT
SWTICH
at
"oN"
position
to
activate
the function,
or
place
at "oFF'
position
to
quit
the
setting
mode
(without
acttvating
the
function).
clocK
2
BATTERY COMPARTMENT
FOR
CLOCK
CONTROL
PANTL
I
(f
uK
LLULr\
r.'
Batterv
installation
and
replacement
ffiinses,
plecas
of AA
batteries
(or
equivalent)
for
running
the
clock
and
2
pieces
of
AA
batteries
for the Auto-backlight
function.
There
are
two
battery
compartrnents,
located
at the
back of
the
unit. The
left one
is
the banery
comparEnent
for
the clock
and
the right
one
is the battery
compartment
for
the
auto-backlight.
Please
use
alkaline baneries.
To
install
the batteries,
slide
open
the battery
cover
and
insert
the bafferies
by
following
the
polarity
marked.
After battery
installation
(for
the clock),
please
press
the RESE-I
BUTTON
once
to
initialize
the
unit.
Now
close
the banery
coven
and the
unit is
ready
for use.
MPORTA}TT
NOTES:
l.
The
two separated
banery
compartrnents
allow
the
clock
to run
even
without the
battenes
for
auto-backlight.
2.
If
the
banenes
for
auto.backlight
run
out
of
power
(or
not
installed),
the
backlight
funcrion
will
stop
(no
backlight).
Under
such
case,
the
clock
will still
work as
usual
and keep
the time accurate
when the battery
power
(for
running
the
clock)
is low,
the
"Battery-Low"
indicator
will be flashing
to
remind the
user.
If this
is the case,
please
replace
the batteries
(for
the
clock)
with new ones.
CoNTROLPANEL
I
(FOR
CLOCK
1)
BATTERY
COMPARTMENT
FOR
CONTROL
PANEL
?
(FOR
CLOCK
2)

MFJ MFJ-121B Specifications

General

Brand	MFJ
Model	MFJ-121B
Category	Clock Radio
Language	English

Summary

MFJ-121B Clock Features and Operation

Battery Installation and Replacement

Instructions for installing and replacing AA batteries for clock and auto-backlight functions, including notes on battery compartments.

Time Radio Signal Reception

Details on activating automatic time signal reception, signal status indication, and troubleshooting weak signal reception.

Time Zone and DST Settings

How to select the appropriate time zone and adjust for Daylight Saving Time (DST) using dedicated switches.

Display Format and Manual Time Setting

Guide to selecting 12/24 hour format and manually setting the time for Clock 1 and Clock 2 if radio reception fails.

Auto-Backlight Function

Instructions for activating and setting the starting time for the auto-backlight feature, which illuminates the display for 8 hours.

12 Month Limited Warranty

Warranty Terms and Conditions

Details warranty coverage, proof-of-purchase requirements, repair/replacement procedures, and limitations for MFJ products.