Kenwood TM-241A User manual

aan
144MHz
FM
TRANSCEIVER
TM-241A/241E
TM-541A/541E
INSTRUCTION
MANUAL
KENWOOD
CORPORATION

Thank you for purchasing this new transceiver.
IMPORTANT:
Please
read
this
instruction
manual
carefully
before
placing
your
transceiver
in
service.
SAVE THIS INSTRUCTION MANUAL.
CAUTION:
Long
transmission
or
extended
operation
in
the
| transceiver to get warm.
Do
not
place
the
transceiver
where
the
heat
sink
(rear
panel)
might
come
in
contact
with
plastic
or
vinyl
surfaces.
l
|HI power mode might cause the rear of this |
This
instruction
Manual
covers
the
following
models.
TM-241A:
144MHz
FM
TRANSCEIVER
(U.S.A.
and
general
markets)
TM-241E:
144MHz
FM
TRANSCEIVER
(U.K.
and
European
markets)
TM-441A:
440MHz
FM
TRANSCEIVER
(U.S.A.
only)
TM-441A:
430MHz
FM
TRANSCEIVER
(General
markets)
TM-441E:
430MHz
FM
TRANSCEIVER
(U.K.
and
European
markets)
TM-541A: 1200MHz FM TRANSCEIVER
(U.S.A. only)
TM-541E: 1200MHz FM TRANSCEIVER
(European markets)
NOTE:
lf disregarded, inconvenience only, no risk of
equipment damage or personal injury.
CAUTION:
Equipment
damage
may
occur,
but
not
personal
injury.
FCC WARNING
‘This
equipment
generates
or
uses
radio
frequency
energy.
Changes
or
modifications
to
this
equipment
may
cause
harmful
interference
unless
the
modifications
are
expressly
approved
in
the
instruction
manual.
The
user
could
lose
the
authority
to
operate
this
equipment
if
an
unauthorized
change
or
modification
is
made.

CONTENTS
Hold/Resume
Programming
...........
25
. BanGScany ase tacnegt esate qnnahadiede 26
1. BEFORE OPERATION ................. 4 Programmable Band Scan ............. 26
2.
SPECIFICATIONS
................00065
6
Memory
Channel
Scan
.........--..--.
27
Memory Channel Lockout ............- 27
3.
ACCESSORIES
...................00005
7
Priority
Alert
Function
..............5:
228
4.
INSTALLATION
INSTRUCTIONS
......
7
REPEATER
OPERATIONS
Transmitter Offsets .................-. 28
5.
OPERATION
Reverse
Function
..............0000
eee
29
CONTROL
FUNCTIONS...........0000008
10
Tone
Operation
.........ecce
cece
e
eee
29
RECEIVER
OPERATION
Tone
Frequency
Selection
.............
29
Reception
.....
pees
t
eee
16
Autopatch
(U.S.A.
version
only)
.......-
30
Frequency
Selection
st
pthe
seats
Sun
aug
ee
17
TONE
/
CTCSS
OPERATION..........
30
Frequency
Step
Selection
............6.
17
DTSS
(Dual
Tone
Squelch
System)
Programmable
VFO
Tuning
Limits
......
18
OPERATION
..........
0.
cece
eee
eee
31
ALT(TM-541A/E
only)
B
Sadia
sei
sceaategevemedye
eaue.
de
19
DRS
(Digital
Recording
System)
TRANSMITTER
OPERATION
.............
20
OPERATION
.....ccccccececceceveeees
34
Time-out
Timer
(TOT)
..-.-
+++
see
e
eee
20
PAGING
peecg
suede
ucts
paces
Ree
41
MEMORY
TONE
ALERT
SYSTEM
...............
47
Microprocessor
Memory
back-up
.......
21
APO
(Automatic
Power
Off)
............
48
Initial
State
2.0.0.0...
eee
21
DIMcDimmer)
Ee
PONT
ee?
oy
er
48
Microprocessor
Initialization
...........
21
BEEP
............
cc
ccccccucccveccuceues
49
Memory
Channel
........-........---5
21
LOCK
/ALOCK
Anitascecs
ae
eeeniaes
49
M ry Contents .........2..2..000005 22
MEISE)
EREV
scacls
cca)
meen
22-6.
BLOCK
DIAGRAM
and
Memory
Channel
Recall
...............
24
SCHEMATIC
DIAGRAM
..
Another
sheet
Memory
Shift
..........-....-.---.
00:
24
7.
MAINTENANCE
.................-...
50
SCAN IN CASE OF DIFFICULTY ........... 51
Scan Operation .............-- cece eee 25
8.
OPTIONAL
ACCESSORIES
...........
52

A WARNING); BEFORE OPERATION
TO PREVENT ELECTRIC SHOCK, FIRE AND OTHER
INJURY. PLEASE NOTE THE FOLLOWINGS:
To avoid risk of electric shock,under no circumstances
should the unit be opened.
Do not place this unit,where it will be exposed to direct
sunlight or close to heating appliances.
To ensure good ventilation, do not put anything on top
of the cabinet and allow at least 15 cm (6 inches) of
space behind the unit.
The power requirement is 13.8 VDC.
Never attempt connection to a 24 VDC source.
Do not place the unit in areas off excessive dust, high
humidity or on unstable surfaces.
Do not drop pieces of metal, needles, coins and other
electrically conductive materials into the unit.

Do not touch the power plug, when your hands are
wet.
Do not pull the power cord, when disconnecting it from
the AC wall outlet. Grasp the plug and ensure that your
fingers do not touch the live pins.
lf an abnormal odor or smoke is detected, immediately
turn
the
power
off
and
pull
out
the
power
plug.
Contact
the
KENWOOD.
service
station
or
our
dealer.
CLEANING
1.
2.
Turn the power off, before cleaning the unit.
Do
not
use
any
type
of
abrasive
pad,
thinner,
benzine
or
any
substances
which
may
damage
the
unit.
Wipe the front panel and other exterior surfaces of
the
unit
with
a
soft
dry
cloth
or
a
soft
cloth
lightly
moistened with water.

2 SPECIFICATIONS
TM-241Awsa‘canaday | TM-241A/E | TM-441Awsavcanada| TM-441A | TM-441E TM-541A/E
| Frequency range MHz 144 to 148 te to 146 j 438 to 450 430 to 440 | 430 to 440 | 1240 to 1300
| Mode F3E(FM)
| Antenna impedance 500
Operating temperature —20°C to + 60°C (—4°F to + 140°F)
cs) | Power requirements 13.8V DC +15%(117~158V)
. Ground Negative
© Current drain | Transmit mode Less than 11A Less than 10A Less than 6A
| Receiver mode Less than 0.6A
Frequency stability Less than +10ppm Less than+3ppm
Dimensions (WXHXD) (mm) (Projections included) 140 X40 X 160(5-1/2" x 1.37/64" x6-19/64") (140 X40 X172(5-1/2" x 1-37/64" X6-25/32")
Weight (kg) 1.2(2.65ibs)
HI 5OW 35W 10W
Output
power
2
MID
Approx
1OW
Approx
10W
=
3 LOW Approx. 5W Approx. 5W 1W
= Modulation Reactance modulation
¢ Spurious radiation Less than — 60 dB
~ | Maximum frequency deviation +5KHz
Audio distortion (at 60% modulation) Less than 3% (300 to 3000 Hz)
Microphone impedance 6000,
f Circuity Double conversion superheterodyne
Intermediate frequency 1st/2nd 30,825MHz/455kHz | 10.7MHz/455kKH2 30.825MHz / 455kHz 159.7MHz/455kHz
g Sensitivity (12 dB SINAD) Less than 0.25nV Less than 0.16 nV
‘@ | Selectivity —6dB: More than 12 kHz -—60dB Less than 24 kHz
& | Squelch sensitivity Less than 0.1 uV Less than 0.177 uV Less than0.1 nV
Output (5% distortion) More than 2 W across 8 © loads
External
speaker
impedance
8Q
‘ Australia: 144 to 148
? Recommended duty cycle: 1 minute Transmit, 3 minutes Reception
Circuits and ratings are subject to change without notice due to advancement in technology.

3 ACCESSORIES
Unpack your new transceiver carefully, and examine it
for visible damage If the equipment has been
damaged in shipment, notify the transportation
company immediately. Save the boxes and packing
material for future shipping.
The following accessories should be included in the box
with the transceiver.
DTMF Microphone
(U.S.A. CANADA only) .........
or
Dynamic Microphone
(GENERAL market only) .......
or
Dynamic Microphone
(EUROPE market only) ........
Microphone Hook
(U.S.A. CANADA only) ........
Mobile Mounting Kit
Bracke, .c.i4ecn0tagene
Screw set ...........0--
Self tapping Screw
(U.S.A. CANADA only) ...
Hex wrench
Stacking plate
(TM-441A/441E/541A/541E)..
T91-0380-X5 1 ea.
T91-0379-X5 1 ea.
T91-0382-X5 1 ea.
J20-0319-24 1 ea.
J29-0436-03 1 ea.
N99-0331-05 1 ea.
N46-3010-46 2 ea.
WO01-0414-04 1 ea.
J21-4147-14 2 ea.
Pe eS ae ee cee
DC power Cable ............. E30-2111-05 1 ea.
Fuse (TM-241A/241E: 15A).. FO5-1531-05 1 ea.
(TM-441A/441E: 10A).. FO5-1031-05 1 ea.
(TM-541A/541E: 8A)... FO5-8021-05 1 ea.
Instruction Manual ........... B62-0031-XX 1 copy
Warranty Card ........c ccc cece ccc eeeee 1 ea.
(U.S.A., CANADA , EUROPE market s only)
4 INSTALLATION INSTRUCTIONS
4-1 INSTALLATION
Mounting Bracket
When installing the transceiver in a vehicle consider the
ease of operation and safety when selecting the
location for the mounting bracket.
1. Install the bracket using the supplied flat washers
and self tapping screws ( 4 pcs.each).
2. Attach the transceiver loosely using the 4 SEMS
screws.
3. Align the grooves in the bracket with the
transceiver’s screws ( Fig. A) and slide the transceiver
to the rear.
4. Adjust the viewing angle in the bracket tc the
desired position ( Fig. B).
5. Hold the transceiver in place and tighten the 4 SEMS
screws using the supplied wrench.

4-2 CONNECTION
4-2-1 Mobile Installations
Cautions :
1. Before installing the power cable, be sure to
remove the negative lead from the battery for
safety.
2. After installation and wiring, be sure to double
check for correct installation before reconnecting
the negative lead to the battery terminal.
3. If the fuse opens, be sure to check that each
conductor has not been damaged by short
circuiting, etc. Then replace with a new fuse of
the same rating.
4. After completing the wiring, wrap the fuse holder
with heat resistant tape to protect against heat
and moisture.
5. Do not remove the fuse even if the power cable is
too long.
eee Ae Mec
A. Battery Connections
Connect the power cable directly to the battery
terminals. Using of the cigarette lighter socket will lead
to a poor connection, and will result in poor
performance. Pay close attention to the polarity of the
cables when connecting them to the battery.
Make sure the positive (+) and negative (—) lead polarity is correct
when connecting to the battery.
Engine bah eee nie Passenger compartment
Fuse
Fuse it =
ey
Select a location where j ~
the power cable is pro-
: tected from heat, mois-
a
| ture of abrasion when
securing the cable.
a
Red
4
\ To the
\ transceiver
Make sure the cable does
not directly contact the
edge of the hole by using
| a grommet.
Chassis or \——_-_—-____/
fire wall
Battery
@ [f the wiring hole in the fire wall or chassis is too small, disas-
semble the fuse holder to thread the wire through the hole.
From passenger
compartment
Thread like this
B. Ignition Noise
This transceiver has been designed to suppress ignition
noise; however, if excessive noise is present, it may be
necessary to use suppressor spark plugs (with resistors).

4.2.2 Fixed Station
A regulated DC power supply (13.8 VDC capable of
supplying at least 11 amperes) is required. PS-33 is
recommended.
1. Never connect the AC power cable to the AC
outlet until all other connections have been
made.
2. Before connecting and disconnecting the power
connector, be sure to turn OFF the POWER :
switches of both the transceiver and the DC
power supply.
| 3. Observe polarity of the DC power cable. The
transceiver operates on 13.8 VDC, negative |
ground. Battery polarity must be correct. The
power cable is color coded :
Red — + (Positive polarity)
Black — — (Negative polarity)
4-2-3 Antenna
The
type
of
antenna
that
is
used
will
greatly
affect
the
performance
of
the
transceiver.
Use
a
properly
adjusted
antenna,
of
good
quality,
to
enable
your
transceiver
to
perform
at
its
best.
The
antenna
input
impedance
is
50
ohms.
Use
50-ohm
coaxial
cable
such
as
RG-8U
or
8D-2V
for
this
connection.
If
the
antenna
is
far
from
the
transceiver
the
use
of
low
loss
coaxial
cable,
such
as
RG-
8U
is
recommended.
Match
the
impedance
of
the
coaxial
cable
and
that
of
the
antenna
so
that
the
SWR
is
less
than
1.5
to
1.
The
protection
circuit
in
the
transceiver
will
activate
if
the
SWR
is
particularly
poor
(greater
than
3
to
1).
High
SWR
values
will
cause
the
transmitter
output
to
drop,
and
may
lead
to
TVI
or
BCI
reports.
»
Caution
:
|
|;
We
recommend
that
you
install
a
high
quality
lightening
arrestor
in
your
antenna
lines
for
protection
against
fire,electric
shock,personal
injury,or damage to the radio itself.

5 OPERATION
5-1-1 CONTROL FUNCTIONS
ALOCK ~ ~ FEV
AL eTcss @ |
eG G88seas
qo eneesenese se Ee
@ jsau le i 6)
TMi eat A AL
SLORTE
@ POWER switch
Press to turn the transceiver on or off.
Press the VFO/MPV or MR/M key and switching the
power on will reset the VFO or MEMORY.
The microphone PF key can be programmed when
the power is switched on.
@ Tuning control
This control is used to select the desired
transmitter/receiver frequency, MHz step, memory
channel, frequency step, tone frequency, scan
direction, etc. :
@ VOL control
This control is used to adjust the volume from the
internal and external speaker (if used). Clockwise
rotation will increase the volume and
counterclockwise rotation will decrease the volume.
@ SQL (Squeich) control
This control is used to select the desired squelch
threshold level.
&) LOW/DIM key
LOW
This function is used to select the transmit output
power level (HI, MID(Except TM-541A/E), or LOW).
DIM
This function is used to select the intensity of the
front panel display illumination. (See page 48)
Pressing the F key for longer than 1 second and then
press the LOW/DIM key while the F indicator is flash-
ing will turn the time-out timer function on and off.
© Microphone connector
Attach the supplied microphone to this connector.
The pin out of the connector is shown in the
accompanying illustration.
@
GND
@
GNO
{Microphone
audial
D
MIC
:
‘audio}
7
(Microphone
Audio)
®
AX
Audio
Output
2)
PTT
(Approx
100
mV/10
k
ohm)
(Push
to
Talk)
@ DWN
uP
5) 8 VDC (Max 150 mA)