Kenwood TM-741A User Manual

144/220 MHz FM MULTI BANDER

TM-641A

144/440 MHz FM MULTI BANDER

TM-741A

144/430 MHz FM MULTI BANDER

TM-741A

144/430 MHz FM MULTI BANDER

TM-741E

INSTRUCTION MANUAL

KENWOOD CORPORATION

©PRINTED IN JAPAN B62-0082-10(K)(T) 92/12 11 10 987654321 91/12 11 10 9 8 7 6

Thank you for purchasing this new transceiver.

IMPORTANT:

Please read this instruction manual carefully before placing your transceiver in service.

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.

This instruction Manual covers the following models. TM-641A: 144/220MHZ FM MULTI BANDER

(U.S.A.version)

TM-741A: 144/440MHZ FM MULTI BANDER

(U.S.A. and Canadian version)

TM-741A: 144/430MHZ FM MULTI BANDER

(General markets)

TM-741E: 144/430MHZ FM MULTI BANDER

(European markets)

NOTE: If disregarded, inconvenience only, no

risk of equipment damage or personal injury.

CAUTION: Equipment damage may occur, but not

personal injury.

Save this instruction manual.

Illustrations show the TM-741A.

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.

1. BEFORE OPERATION

2. SPECIFICATIONS and ACCESSORIES

3. INSTALLATION INSTRUCTIONS

4. OPERATION 4-1 OPERATING CONTROLS

Front Panel ................................................... 12

Microphone .................................................. 16

Display Panel ............................................... 18

Rear Panel and Side case

4-2 RECEIVER OPERATION

Receiver Operation ...................................... 21

Frequency Selection Frequency Step Selection ProgrammableVFO Tuning Limits ... 23 A.B.C.(Automatic Band Change)

Band Selection ............................................. 25

Attenuator ON/OFF ALT (Automatic Lock Tuning)

4-3 TRANSMITTER OPERATION

Transmission

TX Alert ....................................................... 27

Time-Out Timer (TOT)

Bandwidth Selection .................................... 28

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12 12

20 21

22 22

24 25

26 27 27

5 6 8

4-4 MEMORY ......................................................... 29

.Microprocessor Memory Back-up Microprocessor Initialization Memory Channels

Memory Contents ........................................ 30

Memory Entry ............................................. 31

Memory Channel Recall

Memory Banks Clearing Memory .Memory Shift

4-5 SCAN ................................................................ 36

Scan Options

Hold/Resume Programming ........................ 36

Band Scan Programmable Band Scan

.MHz Scan ................................................... 38

Memory Channel Scan ................................ 38

CALL Scan .................................................. 39

V/M/CScan .................................................. 39

Automatic Memory Scan

.Memory Channel Lockout

4-6 REPEATER OPERATION

Transmitter Offset

Reverse Function Tone and CTCSS Operation Autopatch Operations

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29 29 30

32 32 35 35

36 37

39 40 41 41 41 41

4-7 DTSS

4-8 PAGING ......................................................... 46

4 - 9 TONE ALERT SYSTEM................................ 51

4-10 AUTOMATIC POWER OFF (APO) 4-11 DIMMER (DIM)

4-12 BEEP TONE LEVEL ADJUSTMENT.... 53

4-13 BEEP TONE FREQUENCIES ....................... 53

4- 14 KEYLOCKS ................................................... 54

5. CLOCK ................................................................ 55

5 -1 CURRENT TIME AND DATE

5- 2 OTHER CLOCK FUNCTIONS

..............................................................

DTSS Code DTSS Code Selection

Using the DTSS Function ............................ 45

Using DTSS with a Repeater ....................... 45

Paging Code Memories

Code Selection ............................................. 47

Code Transmission

Paging Code Monitoring Code Lockout

Backup Switch.............................................. 55

Setting the Current Time and Date Current Time, Calender and Stopwatch in the

Clock display

Time-ON/Time-OFF Programming

Activating the SLEEP Timer

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44 44 44

47 48

49 50

55 55

5 - 3 CLOCK POSITION ON THE FREQUENCY

DISPLAY

Transceiver Function ON or OFF Transceiver Function OFF Transceiver Function ON Tri-Bander Clock Operation in the Frequency Display 60

6. MAINTENANCE

In Case of Difficulty .................................... 62

7. OPTIONAL ACCESSORIES CTCSS unit (TSU-7) 65 DTMF unit (DTU-2) 65 Panel Separation Kit (PG-4K^ PG-4L) 68 Bracket

Band Unit

BLOCK DIAGRAM and SCHEMATIC DIAGRAM

One additional band may be installed using options described in this manual. Operation instructions remain the same for the radio when uses a dual band or tri-band configuration.

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NOTICE

58 59 59

61 64

70 71

1. BEFORE OPERATION To prevent electric shock, fire and other

injury, please note the following:

Never remove the case unless instructed to do in this Instruction Manual. If the internal parts are touched accidentally, a serious electric shock might occur.

Do not place the unit in areas of 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 place this unit where it will be exposed to direct sunlight or close to heating appliances.

Do not place anything on top of the cabinet.

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.

If an abnormal odor or smoke is detected, immediately turn the power off. Contact the KENWOOD service station or your dealer.

Cleaning

1. Turn the power off before cleaning the unit.

2. Do not use any type of abrasive pad, thinner, benzine or any substances which may damage the unit.

3. 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 and ACCESSORIES 2-1. SPECIFICATIONS

E R

R A N

I T T E R

144 MHz Band

Frequency range MHz

Mode Antenna impedance Operating temperature Power requirements 13.8VDC±15% (11.7~15.8V) Ground

Current drain

Frequency stability Dimensions (WXHXD) 150X50X175 mm Wa^ 1.6 kg

Output power

Modulation Spurious radiation Less than —60dB Maximum frequoxy cfeviation Audio distortion (at 60% modulation) Microphone impedance

U.S. A and Canada 144 ~148

Other market 144 ~148 —

TM-741E

Transmit mode Receiver mode

MID

LOW Approx. 5W

144 ~146 —

Less than 11.5A

50W 25W

220 MHz Band

220 ~225

F3E(FM)

50D

-20'C~+60X (-4T~ +140°F)

N^ative

Less than 7.0A

Less than 1.2A

±10ppm

low

Reactance modulation

±5kHz

Less than 3%

6oon

440/430 MHz Band

438 ~450 430 ~440 430 ~440

Less than lO.OA

35W

144 MHz Band

E C E

NOTE: 1. Circuit and ratings are subject to change without notice, due to developments in technology.

Circuitry Intermediate frequency lst/2nd Sensitivity (12 dB SIN AD) Selectivity —6 dB Selectivity —60 dB

Squelch sensitivity Output (5% distortion)

External speaker impedance

2. Recommended duty-cycle: 1 minute Transmission, 3 minutes Receptioa

10.7 MHz/455 kHz

Double conversion superheterodyne

More than 2 W (8D load )(5% distortion)

220 MHz Band

30.825 MHz/455 kHz

Less tJian0.16;[/V (—10 dB/z) ^

More than 12 kHz

Less than 24 kHz

Less than 0.1 /¿V (—14dB//)

440/430 MHz Band

21.6 MHz/455 kHz

2-2. ACCESSORIES

Unpack your transceiver carefully and confirm that the accessories listed below are included in the box.

DTMF Microphone

( U.S.A. and Canada only)

or Microphone

(European version)

or Microphone

Microphone Hook..................... J20-0319-XX 1

( U.S.A. and Canada only)

Mobile Mounting Kit.................................................... 1

Bracket

Screw set ....................... N99-0331-XX

.................

..........................

(General market)

..........................

T91-0397-XX T91-0398-XX T91-0396-XX

J29-0454-XX

............

1 1 1

Self tapping Screw

...................

N46-3010-46

............

(U.S.A. and Canada only) Hex Wrench DC power Cable

............................

......................

W01-0414-XX .... 1

E30-3034-XX .... 1

FusedSA) ................................. F05-1531-XX .... 1

Instruction Manual Quick reference Warning sheet

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B62-0082-XX 1 copy

B59-0441- x x 1 copy

B58-1001-XX 1 copy Warranty Card (U.S.A., Canada and European version

only) ............................................................................ 1

After unpacking Shipping container: Save the boxes and packing in the event your unit needs to be transported for remote

operation, maintenance, or service.

3. INSTALLATION INSTRUCTIONS 3-1. INSTALLATION

3-1-1. Installing the Microphone and Setting

the Clock Backup Switch

Before installing be sure to turn off the power switch.

1. Slide the release button on the front panel to the right. Carefully pull the front panel toward you from the right, then remove the whole panel unit. Be careful with the cord connecting the front panel unit to the chassis. (Fig. 1)

2. Insert the microphone connector into the microphone socket on the right of the main unit until it clicks. Make sure the tab on the connector is on top.

3. Place the microphone cord in the holder groove. (Fig. 2)

■BACKUP SWITCH

Inside the small cover of the front panel unit there is a Backup Switch to retain clock memory. If you set the switch ON »turning off the POWER switch, disconnecting the power cable or an intermittent power failure will not erase the clock memories.

4. Slide the small cover off of the front panel unit as shown in the accompaning illustration. (Fig.3)

5. Gently lift up on the cable near the grommet.

6. Set the Backup switch ON. Pay attention to the labelings.

7. Push the grommet down into its slot.

8. Replace the small cover until it clicks.

9. Route the cable as desired in the slots on the rear of the front panel.

1 ^

---------

[

)

10. Align the hook on the back of the front panel with the slot on the left of the chassis before replacing the front panel.

11. Push the front panel toward the chassis until it locks completely. Take care not to trap the connecting cord. The connecting cord is easier to manage when it is put in the groove on the back of the front panel.

12. Set the date and time ( See page 55 ).

(Fig. 1)

microphone

connector

release button

slot

holder

(Fig. 2)

(Fig. 3)

3-1-2. Mounting Bracket

Notes

1. When installing the transceiver in a vehicle consider ease of operation and safety when selecting the location for the mounting bracket.

2. Install the bracket securely so that it will not come off due to vibration.

1. Install the bracket using the supplied flat washers and self tapping screws (4 pcs. each).

2. Attach the transceiver loosely using the SEMS screws (4 pcs.).

3. Adjust the viewing angle of the bracket to the desired position.

3-2. CONNECTION

3-2-1. 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 8D2V for this connection. If the antenna is far from the transceiver the use of low loss coaxial cable, such as RG8U 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 lightning arrestor in your antenna lines for protection against fire,electric shock,personal injury,or damage to the radio itself.

Hold the transceiver in place and tighten the 4 SEMS screws using the supplied wrench.

3-2-2. Mobile Installations

Battery Connections

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.

Make sure the positive (+) and negative (—) lead polarity is correct when connecting to the battery.

Engine compartment-——-Passenger compartment

Red

Fuse 0 f

\ To the

\transceiver

select a location wh«re the power cable ¡8 pro tected from heat, mois ture or abrassion when securing the cable.

If the wiring hole in the fire wall or chassis is too small, disassemble the fuse holder to thread the wire through the

hole.

________

Chassis or

"^fire wall

j£

Make sure the cable does not directly contact the edge of the hole by using a grommet.

From passenger compartment

Thread like this

Caution Leave enough space around the fan on the rear panel for good ventilation.

Connect the power cable directly to the battery terminals. Use of the cigarette lighter socket will lead to poor connection, and will result in poor performance. Pay close attention to the polarity of the cables when connecting them to the battery.

3-2-3. Fixed Station

A regulated DC power supply (13.8 VDC capable of supplying at least 12 Amperes) is required. The PS-430 and the PS-50 are recommended.

Caution:

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)

Caution: Leave enough space around the fan on the rear panel for good ventilation.

CONTROL SEITECT keys (Press) / Current Operating Band indicators These keys are used to select the key operating band.(To change the transmission

band, use the BAND SELECT key.) The green light shows which band will be controlled by the front panel controls.

When optional band unit is

installed.

BAND SELECT keys (Press) / VOL controls {Rotate) These keys are used to select the transmit band. They are also used to select the band you wish to control with the front panel switches. When a key is pressed the ”PTT” indicator will flash as a visual signal to show which band has been selected.

SQL (Squelch) controls

These controls are used to separately adjust each squelch threshold level.

VOL controls (Rotate) These controls are used to adjust the volume.

I Function key Assignments

Press the F key for longer than 1 second so that the key indicator begins to flash, then press the key below.

Key

F 1 Sec, F 1 Sec, F1 Sec,

F 1 Sec,

F 1 Sec, F 1 Sec,

F 1 Sec, F 1 Sec, F 1 Sec,

F 1 Sec,

CONT SEL

F 1 Sec,

BANDSEL

VFO

MR MHz

CALL

SHIFT

TONE

REV DTSS LOW

Automatic Power off functior

Function

Change Scan Hold/

Resume mode

Memory channel lockout

will turn on or off

The lower limit of the

programmable VFO

The upper limit of the

programmable VFO

Tone frequency selection

Beep tone level adjustment

DTSS code selection

Time-out timer on or off

Select receive detection

output band from the

microphone connector

Band on or off

Refer to

P.36 4-5-2

P.40 P.52

P.23 4-2-4

P.42

P.53 P.44 4-7-2

P.28

P.18 4-1

P.25 4-2-6

4-5-10

4-10

4-6-3 4-12

4-3-3

• Press and hold the F key, then the key Key Function

F+ VFO

F+ MHz

F+ MR F+ TONE

F+ DTSS F+ LOW F+

CONT SEL F+

BAND SEL F+ PIT

Enter the programmable scan

lower frequency limit

Enter the programmable scan

upper frequency limit

Clear the displayed memory

channel data

Bank status display

DTSS delay time selection

Memory consolidation

Automatic Memory scan

Clear Memory Bank

TX Alert

DClow.

Refer to

P.38 4-5-4

P.35 4-4-8 P.32 4-4-7

P.45 4-7-4 P.32 4-4-7

P.39 4-5-9

P.35 4-4-8 P.27 4-3-2

• Press and hold the key below and turn on the power switch.

Key Function

MR +

Power ON

F+BANDSEL

+ Power ON

Memory reset of all bands

Memory reset of a band

Refer to

P.29 4-4-2

Key

VFO+

Power ON

VFO-i-BANDSEL

-I- Power ON

MHz+

Power ON

CALL+

Power ON

F+SHIFT+

Power ON

F+TONE+

Power ON

F+DTSS+

Power ON

F-I-LOW +

Power ON

Function

VFO reset of all bands

VFO reset of a band

All lock on or off during Lock

Demonstoration mode

on or off

Tone alert selection

Set the time and date

With optional DTU-2: The microphone PF key can be used to change the beep tone frequency.

Wide /Narrow selection

Refer to

P.30 4-4-2

P.54 4-14

P.40

P.51 4-9

P.55 5-1-2

P.66 7-3-1

P.28 4-3-4

4-1-2. Microphone

(2) ®

®d)UP/DWN switches

These switches can be used to increase or decrease the VFO frequency, the Memory channel number, and the Tone frequency, etc..

d)PTT (Push to Talk) switch

The transceiver will transmit whenever this switch is depressed. Scan operations may be canceled by pressing this switch without

transmitting.

0LOCK switch

This key will deactivate all functions of the

microphone except the PTT function and DTMF

keypad.

(Dl6-Tone DTMF keypad

These buttons are used to activate the DTMF

encoder.

(DPF(Programmable Function) key This key can be programmed to perform any of the following functions: BAND SEL (*^) key (Initial setting from the factory); or MHz, T.ALT, TONE, REV, DTSS,

LOW, MUTE, or CONT SEL (^) key.

To program the key use the following procedure:

1. Turn off the POWER switch on the transceiver.

2. Press and hold the key on the front panel of the set that corresponds with the function you wish to program the microphone key to perform.

3. Turn on the POWER switch while the key on the front panel is held in.

4. Release the front panel key.

(^) Press the PF key set in the CONT SEL or BAND

SEL key to cause the radio to switch from a band to the other. Pressing the PF key for longer than 1 second will not initiate scanning Press the PF key set in the CONT SEL or BAND SEL key to cause the radio to switch from one band to the other. Pressing the PF key for longer than 1 second will not initiate scanning.

Press and hold the F key on the front panel as you turn on the POWER switch of the transceiver and then release the F key.

(2X:ALL key VFO key MR key

These keys function are like the CALL, VFO,or MR key on the front of the radio. (See page 12.and page 14) These keys can be programmed to function as the PF key. To program the key :

1. Turn off the POWER switch on the transceiver.

2. Press and hold one of these keys.

3. Turn on the POWER switch. The PF-2/3/4 will appear in the display.

4. Press the key on the front panel that you wish to program the microphone key.

5. Release the microphone key.

To release the programming reset the VFO.

(saSffflSs issBBRBs ibbBBBBs^

iBBni I I

One additional function can be programmed that is not included on the front panel of the transceiver. This is known as the MONITOR function. This will allow you to open squelch of the selected band to check the band for a clear frequency. This will function even if you are operating in the CTCSS decode mode. MONITOR programming

Turn on

Press and hold MR key............................... PF2

MR key.............................. PF3

MR key.............................. PF4

(Dl750key (European version) The transceiver will transmitt with 1750 Hz repeater access tone whenever this switch is depressed.

►Microphone terminal connection

(Front view)

4-1-3. Display Panel

Receive audio for the selected TX band (100mV/l0kn)

Receive Audio Output Band Selection (RD) connector

The RD terminal will supply an audio signal during receive on the same band that has been selected for

transmit. Press the F key for longer than 1 second, and

then press the CONT SEL key for the desired band. An indicator will appear in the frequency display of the selected band.

-----

lOHS

Receive Audio output display The 100 kHz dot in the band lights

L, rr n n o

Wl /.u u u

(9>

—+

)REV

®CTCSS

)DTSS

)CO

/1 o o ^ c

LLCfO U.U:U.U

^Bgr

BU SY

SSRF—1 — B — a

(ij)

IlllllllllllllrS^

Indicates the TX band. Displays the selected transmitter offset direction. On when the Reverse function has been activated. With the optional CTCSS unit TSU-7: On when the Tone Decode function is active. On when the Tone Encode function is active.

With optional DTU-2

On when the DTSS function is active.

On when Carrier Operated scan is selected. On when the Tone Alert function is active.

L,M

—+

REV

CTCSS CO

DTSS ^

SO.

— +

REV

CTCSS CO

DTSS ^

Ts 8.8:8.8s Шв88:8.8.1 !Ts 88:8.8.

88 'Ш“!!1Ч“Ч!Ш SI 88 |ИРдаччч<Ш SI *88 в»'Ш!Ш|Ш! SI

^188 Displays the operating frequency to the ®

nearest kHz digit, or the tone frequency. f-------1—

• The indicator flashes when scanning.

*B 8

L M

On whenever the F key has been OFF depressed. © SLEEP Shows the last memory channel number that was selected. The ★ indicator is on © LOCK

when the Memory channel will be skipped during Memory channel scan. A,LOCK On in paging mode.

-On when the squelch opens. @ apo This level meter indicates the relative receiver signal strength or the relative @ TOT transmitter power output.

On during transmit. @ д.В.С. Indicates the relative output power setting for transmit. No indicator @> MUTE

indicates full power.

■4ЕШ^

CTCSS CO m ON

Чжг

_ A.LOC C AP

J TOT

A.B.C MUTE

1200MHz band only; On when the Automatic

-Lock Tuning function is active.

28/50 MHz band only; On when Attenuator is

on. On when the TIME ON/OFF function has been activated. On when the SLEEP TIMER function has been activated. On when the Lock function has been

activated. On when the All Lock function has been

activated. On when the Automatic Power Off

function has been activated. On when the Time-Out Timer function

has been activated.

On when the Automatic Band Change function has been activated. On when the volume of the RX band is reduced.

4-1-4. Rear Panel and Side Case

144MHz.

■ 144MHz

TM-741A/741E-

440/430MHZ

TM-641A

220MHz

(DANTENNA connector Attach an antenna with a low SWR and impedance of 50 ohms. (2) 13.8 VDC power input connector Connect the supplied DC power cable to this connector. Pay close attention to the polarity. Red is positive and black is negative. (DFuse holder Contains a 15A fuse. Do not use a larger fuse as damage might result to the transceiver. (3) External speaker jack (Rear panel) The speaker should have an impedance of 8 ohms. The audio is switched to the external speaker (no sound is output from the built-in transceiver speaker).

■TM-741A/741E 440/430MHZ

TM-641A

220MHz

Example

144MHz band

(5)External speaker jack (Side case) The speaker should have an impedance of 8 ohms. The audio is switched from the built-in transceiver speaker to the external speaker (no sound is output from the built-in transceiver speaker).

Example

We recommend the use of the optional external speaker

SP-50B.

Fig.l

2. Turn on the Power Supply, then turn on the transceiver’s POWER switch. The display should light after 1 second. Fig.l shows examples of frequencies that will appear on the various models. The frequencies shown above are the default frequencies after a microprocessor reset. If the display shows incomplete data or you think the displayed frequency is in error you should reset the microprocessor. ( Memory Initialization on page 29 )

Perform the following steps for each band.

so that the operating band indicator lights (green).

Rotate the VOL control clockwise until a signal or

noise is heard coming from the speaker.

4. Rotate the tuning control or press the microphone UP/DWN switches to select an open channel.

5. Rotate the SQL control clockwise until the noise just

disappears and the BUSY indicator turns off. This point is known as the Squelch Threshold point.

6. Select the desired operating frequency using the microphone or tuning control. When a signal is received the S-meter will deflect and the BUSY indicator will turn on.

7. Turn off the transceiver’s Power switch before you turn off the power supply, or in a vehicle, before you stop the engine.

4-2-2. Frequency Selection

You can change the dial frequency while in the VFO mode. The frequency can also be stored in memory, or in the call channel.

1. Press the VFO key to select the VFO mode.

2. Rotate the tuning control, or press the microphone UP/DWN switches to select the desired frequency.

Mode selection

You can select the VFO mode. Memory channel mode, or Call channel mode using the following keys.

1. Press the VFO key to select the VFO mode.

2. Press the F key momentarily. The F indicator should light on the display.

3. Press the REV/STEP key within 10 seconds of pressing the F key. The current frequency step size will be displayed.

4. Rotate the Tuning control or press the microphone UP/DWN keys until the desired tuning step size appears in the display.

CS)

tons

,1,. n o n n

GE)

step Size [kHz]

5^10^15?i20?=i12.5=i25i*

5. To complete the programming of the step size you can press any front panel key or simply wait 10 seconds and the microprocessor will automatically return to the normal frequency display.

4-2-3. Frequency Step Selection

T0 select the desired tuning or scan step size use the following procedure:

The chart below illustrates the way the displayed frequency will change when you change from one step size to another.

5,10,15,20 to 12.5,25

0,5,10,15 0 20,25,30,35 25 40,45,50,55 50

60,65,70,75,

80,85,90,95

12.5,25 to 5,10,15,20 0

12.5 25

37.5 50

62.5 60 75

87.5

0 10 20 30 50

70 80

For example: Assume you are presently displaying a frequency of

439.920 MHz and had previously selected a 20 kHz step size. If you were to change the step size to 12.5 kHz the display would then read 439.925 MHz.

1. Press the VFO key to select the VFO mode. Rotate the Tuning control until the desired lower

tuning range appears on the frequency display.

For example, you might want to select the 438 MHz

band and dial up 438.100 MHz.

2. Press the F key,for longer than 1 second, then press

the CALL key.

more than

1 sec

Rotate the Tuning control until the desired upper

/¿7VS

^unnn inn

iW i.uuu '<30. luu

tuning range appears on the frequency display.

Press the F key for longer than 1 second, then press the SHIFT key.

4-2-4. Programmable VFO Tuning Limits

The radio provides the capability of programming the VFO tuning range, in 1 MHz band segments, as well a providing a separate programmable band scan function. (See section 4-5.) For example, you could tell the transceiver that you only wish to tune the 438.000 MHz and 439.000 MHz band segment by specifying any frequency with these two segments. The Tuning controls would then only tune within these specific bands. The procedure for specifying the bands is described below.

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lore than

1 sec

(^3HIFT^

To confirm that the programming was properly

5. performed rotate the Tuning control. The transceiver should not go above or below the programmed band limits.

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To clear both programmed limits simultaneously, turn the Power off ,then;

ALL BAND mode

Press and hold the VFO key, then turn the Power switch on (VFO RESET See page 30).

INDIVIDUAL BAND mode

2. As soon as a signal is received on any band, the TX circuit will become active on that band.

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Press and hold the VFO key and the BAND SEL key for the band you want to clear, then turn the Power

switch on. You can reprogram either limit independently by fol lowing the appropriate instructions above.

4-2-5. A.B.C.(Automatic Band Change)

The A.B.C function allows you to exchange the RX band to the TX band automatically whenever a signal is received and the squelch is open.

1. Press the F key and then press the MUTE/ABC key.

The A.B.C. indicator will light on the display.

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A.B.C.

(^MUTE^

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3. If you press the PTT switch,

The A.B.C. function will be released. The band remains TX band.

If the PTT switch is not pressed,

Within 2 seconds after the signal goes off, the band will be returned to RX band.

If you press the BAND SEL key.

The A.B.C function will be released.

+ 53 hidden pages

Kenwood TM-741A User Manual

TM-641A

TM-741A

TM-741A

TM-741E

CONTENTS

1. BEFORE OPERATION To prevent electric shock, fire and other

2. SPECIFICATIONS and ACCESSORIES 2-1. SPECIFICATIONS

2-2. ACCESSORIES

3. INSTALLATION INSTRUCTIONS 3-1. INSTALLATION

■BACKUP SWITCH

3-2-1. Antenna

3-2-3. Fixed Station

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4-2-2. Frequency Selection

Mode selection

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