Kenwood TM-241A User manual

GOOMNA»
144MHz FM TRANSCEIVER
TM-241A/241E
430/440MHz FM TRANSCEIVER
TM-441A/441E
1200MHz FM TRANSCEIVER
TM-541A/541E
INSTRUCTION MANUAL
KENWOOD CORPORATION
62-0031-00(T)

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:
NOTE:
If
disregarded,
inconvenience
only,
no
risk
of
equipment
damage
or
personal
injury.
CAUTION:
Long transmission or extended operation in the
HI power mode might cause the rear of this
transceiver to get warm.
Do not place the transceiver where the heat sink
(rear panel) might come in contact with plastic
or vinyl surfaces.
Equipment
damage
may
occur,
but
not
personal
injury.
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)
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
Ls
Ch PON
BEFORE:OPERATION | s..2c00 e064 820 ees 4
SPECIFIGATIONS 22tecicae spacers > 6
ACCESSORIES (20a) tien 3 7
INSTALLATION INSTRUCTIONS ...... ¥
OPERATION
CONTROL FUNCTIONS. 2 ......00000 a0. 10
RECEIVER OPERATION
Reception! © ....2. lot eer aT JEON 16
Frequency Selection ................... 17
Frequency Step Selection .............. 17
Programmable VFO Tuning Limits ...... 18
ALT(TM-541A/E only)...........-.-0-.- 19
TRANSMITTER OPERATION.............- 20
Time-out Timer'CFOT)) cc oceccen esses 20
MEMORY
Microprocessor Memory back-up ....... 21
[ittialiState oon. cee pis os So asa Oars 21
Microprocessor Initialization ........... 21,
Memory'Channél) 22:8. .60.. 62. c.eeces- 21
Memory Contents 2... 2.0 e..s.e3 bbe. ees 22
Memory Entfy) ). .2:0: .- cee sates S38. oes 22
Memory Channel Recall ............... 24
Memory SINE ya. cna sic eae bees kee 24
SCAN
ScaniOperation «is cscu cewsiesuwun aes 25
6.
Hold/Resume Programming ........... 25
Band Scatin’ 3o3. 2s Scdenes seems snares 26
Programmable Band Scan ............. 26
Memory ChannelScan ................ 27
Memory Channel Lockout ............. 27
Priority Alert Function .........60. e000 28
REPEATER OPERATIONS
Transmitter Offsets ................... 28
Reverse Function 29
Tone Operation 29
Tone Frequency Selection ............. 29
Autopatch (U.S.A. version only) ........ 30
TONE / CTCSS OPERATION.......... 30
DTSS (Dual Tone Squelch System)
OPERATION esnadeiccn arsine et annie: 31
DRS (Digital Recording System)
OPERATION. fin. ate ce see es bah ges ak 34
PAGING Xi. 5. hun. etter pase nes 41
TONE AEERT, SYSTEM... dcccccew ess. 47
APO (Automatic Power Off) ... 48
DIM@Diramer): ee sc uss 3 se asx 05.2 208 < 48
BEEP IMs $09 [er mos 49
LOCK/MILOCK! Men a5 a BAA 49
BLOCK DIAGRAM and
SCHEMATIC DIAGRAM Another sheet

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.
If 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
Ee
(a8
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-241A(USA) | TM-241A/E |TM-441A(US.A)| TM-441A TM441E TM541A/E
Frequency range MHz 144 to 148 | 144 to 146| 438 to 450 430 to 440 | 430 to 440 | 1240 to 1300
Mode F3E(FM)
Antenna impedance 500
Operating temperature —20°C to +60 (—4F to +1407)
‘s | Power requirements 13.8V DC +15%(117~158V)
S Ground Negative
S Cc t drai Transmit mode Less than 11A Less than 10A Less than 6A
urrent drain :
Receiver mode Less than 0.6A
Frequency stability Less than +10 ppm Less than 3ppm
Dimensions (WXHXD) (mm) (Projections included) 14040 x 160(5-1/2” X1-37/64"X6-19/64") (140 X40 X172(5-1/2"X 1-37/64"X6-25/32”)
Weight (kg) 1.2(2.65lbs)
HI 50wW 35W 10W
Output power * MID Approx 10W Approx 10W i
5 LOW Approx. 5W Approx. 5W 1w
_ Modulation Reactance modulation
2 | Spurious radiation Less than — 60 dB
£ Maximum frequency deviation E5KHz
Audio distortion (at 60% modulation) Less than 3% (300 to 3000 Hz)
Microphone impedance 6000,
Circuity Double conversion superheterodyne
Intermediate frequency 1st/2nd 10.7MHz / 455kHz 30.825MHz / 455kHz _59.7MHz/455kHz
S Sensitivity (12 dB SINAD) Less than 0.16 «V
'S | Selectivity —6dB: More than 12 kHz —60dB_ Less than 24 kHz
ce | Squelch sensitivity Less than 0.1 nV Less than 0.177 nV Less than 0.1 uV
Output (5% distortion) More than 2 W across 8 Q, loads
External speaker impedance 80
otes : 1.Circuit and ratings are subject to change without notice due to advancement in technology.
2.* Recommended duty cycle :1 minute: Transmit,3 minutes Reception

3 ACCESSORIES 4 INSTALLATION INSTRUCTIONS
Unpack your new transceiver carefully, and examine it
for visible. pes If ets pra ie has been 4-1 INSTALLATION
damaged in shipment, notify the transportation 7
company immediately. Save the boxes and packing Mounting Bracket
material for future shipping. When installing the transceiver in a vehicle consider the
The following accessories should be included in the box ease of operation and safety when selecting the
with the transceiver. location for the mounting bracket.
DTMF Microphone 1. Install the bracket using the supplied flat washers
(U.S.A. CANADA only) ......... T91-0380-X5 1 ea. and self tapping screws ( 4 pcs.each).
or E " 2. Attach the transceiver loosely using the 4 SEMS
Dynamic Microphone screws.
ENE market only) ......- T91-0379-X5 1 ea. 3. Align the grooves in the bracket with the
a Microphone transceiver’s screws ( Fig. A) and slide the transceiver
(EUROPE market only) ........ T91-0382-X5 1 ea. totherear, :
Microphone Hook 4. Adjust the viewing angle in the bracket to the
(U.S.A. CANADA only) ........ J20-0319-24 1 ea. desired position ( Fig. B). ;
Mobile Mounting Kit 5. Hold the transceiver in place and tighten the 4 SEMS
BYACKEES 51. ~ ave. oterare nia sieve J29-0436-03 1 ea. screws using the supplied wrench.
SCROW'SOE coca. morele e onstese N99-0331-05 1 ea.
Self tapping Screw
(U.S.A. CANADA only) ... N46-3010-46 2 ea.
Hexwrench: ...26c00sece08ce0s W01-0414-041 ea.
Stacking plate
(TM-441A/441E/541A/541E).. J21-4147-14 2 ea.
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
Weartany (Cad... ais 2 sii ves won oxen sce 1 ea.
(U.S.A., CANADA , EUROPE market s only)

4-2 CONNECTION
4-2-1 Mobile Installations
Cautions : Make sure the positive (+) and negative (—) lead polarity is correct
1. Before installing the power cable, be sure to wvizen iconnecdngiiesthicibatteny
remove the negative lead from the battery for Pete Gore er Passengeneoinnartnent
safety. To the
2. After installation and wiring, be sure to double transceiver
check for correct installation before reconnecting
the negative lead to the battery terminal. Moke sure acti one
3. If the fuse opens, be sure to check that each Battery ‘ "when sian of ie hele by ua
Chassis or
conductor has not been damaged by short >
fire wall
circuiting,
etc.
Then
replace
with
a
new
fuse
of
If
the
wiring
hole
in
the
fire
wall
or
chassis
is
too
small,
disas-
the
same rating.
semble the
fuse
holder
to thread the
wire through
the
hole.
4.
After
completing
the
wiring,
wrap the
fuse
holder
From
passenger
with
heat resistant
tape to
protect
against
heat
oe
and
moisture.
Thread
like
this
.
Do
not
remove
the fuse
even
if
the
power
cable
is
too
long.
ao
A. Battery Connections
Connect the power cable directly to the battery B. Ignition Noise
terminals. Using of the cigarette lighter socket will lead : ; . Late 3
to
a
poor
connection,
and
will
result
in
poor
This
transceiver
has
been
designed
to
suppress
ignition
performance. Pay close attention to the polarity of the "0ise; however, if excessive noise is present, it may be
cables
when
connecting
them
to
the
battery.
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. The PS-430
or the PS-50 are recommended.
1. Never connect the AC power cable to the AC
outlet until all other connections have been
made.
. 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)
nN
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
- - REV =
miesBBBBs a0
ae
AL cToss
@ 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 (Squelch) 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
@
GND
(Microphone
audio)
D
MIC
(Microphone
Audio).
ery
®
RX
Audio
Output
@
pir
(Approx
100
mV/10
k
ohm)
(Push
to
Talk)
@
DWN
@ up
@® 8 VDC (Max 150 mA)