Kenwood TM-451A User Manual

TM-251A/251E TM-451A/451E

144, 430/440 MHz FM TRANSCEIVER

INSTRUCTION MANUAL

KENWOOD CORPORATION

©PRINTED IN JAPAN B62-0455-08(K, P, E, M)

94/12 11 10 9 8 7 6 5 4 3 2 1 93/12

Notice to the user:

One or more of the following statements may be applicable to this equipment.

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.

INFORMATION TO THE DIGITAL DEVICE USER REQUIRED BY THE FCC

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation.

This equipment generates, uses and can generate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that the interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

•Reorient or relocate the receiving antenna.

•Increase the separation between the equipment and receiver.

•Connect the equipment to an outlet on a circuit different from that to which the receiver is connected.

Models Covered by this Manual

TM-251A: 144 MHz FM transceiver {U.S.A./ Canada/ General)

TM-251E: 144 MHz FM transceiver (Europe)

TM-451A: 440 MHz FM transceiver (U.S.A./ Canada)

430 MHz FM transceiver (General)

TM-451E: 430 MHz FM transceiver (Europe)

Note:

►The TM-251 series is used for all illustrations and all LCD example displays.

►Functions requiring the microphone keypad, such as Remote Control, cannot be used without a keypad-equipped microphone. This type of microphone is optional for some transceiver versions.

•Consult the dealer for technical assistance.

THANK YOU

We are grateful you decided to purchase this KENWOOD FM transceiver. The TM-251/TM-451 series of mobile transceivers were developed to satisfy the requirement for a compact rig that’s simple to operate yet has superior performance. Users of this series will discover the transceiver’s Menu Set-up method for feature configuration recently incorporated in other KENWOOD products.

KENWOOD believes that the compact size coupled with the reasonable cost will guarantee your satisfaction with this product.

PRECAUTIONS

Please observe the following precautions to prevent fire, personal injury, and transceiver damage:

•Do not transmit with high output power for extended periods. The transceiver may overheat.

•Do not modify this transceiver unless instructed by this manual or by some other approved KENWOOD communication.

•Do not expose the transceiver to long periods of direct sunlight or place the transceiver close to heating appliances.

•Do not place the transceiver in excessively dusty or humid areas, or on unstable surfaces.

•If an abnormal odor or smoke is detected coming from the transceiver, turn OFF the power immediately. Contact a KENWOOD service station or your dealer.

•The transceiver is designed for a 13.8 V power source. Never use a 24 V battery to power the transceiver.

CONTENTS

FEATURES ................................................................	1
ACCESSORIES .........................................................	1
CONVENTIONS FOLLOWED IN THIS MANUAL ..	2
PREPARATION FOR MOBILE OPERATION ............	3
MOBILE INSTALLATION ......................................	3
Installation Example ............................................	3
DC POWER CABLE CONNECTION .....................	4
Replacing Fuses ..................................................	6
ANTENNA CONNECTION ....................................	6
PREPARATION FOR FIXED STATION
OPERATION .............................................................	7
DC POWER SUPPLY CONNECTION .................	7
Replacing Fuses ................................................	8
ANTENNA CONNECTION ...................................	8
ACCESSORY CONNECTIONS ...............................	9
EXTERNAL SPEAKER ........................................	9
MICROPHONE.....................................................	9
PACKET EQUIPMENT ........................................	9
Data Connector Pinout.......................................	10
YOUR FIRST QSO ...................................................	11
GETTING ACQUAINTED........................................	12
FRONT PANEL ....................................................	12

REAR PANEL ....................................................	15
MICROPHONE ..................................................	16
DISPLAY ............................................................	17
MENU SET-UP .......................................................	22
MENU DESCRIPTION .......................................	22
MENU A ACCESS..............................................	22
MENU A CONFIGURATION ..............................	23
MENU B ACCESS .............................................	24
MENU B CONFIGURATION ..............................	24
CONFIRMATION BEFORE OPERATION .............	26
REAR PANEL ....................................................	26
FRONT PANEL ..................................................	27
RECEIVING ............................................................	28
SWITCHING POWER ON/OFF..........................	28
VOLUME ADJUST .............................................	28
SQUELCH ADJUST............................................	28
Noise Squelch ..................................................	28
S-Meter Squelch ..............................................	29
SQUELCH HANG TIME .....................................	29
BAND SELECT ..................................................	30
Selecting AM/FM Mode (TM-251A/E only) ...	31
VFO MODE ........................................................	32
SELECTING FREQUENCIES ............................	32
Tuning Control .................................................	32

Programmable VFO .........................................	33
Microphone [UP]/[DWN] Buttons......................	34
FREQUENCY STEP SIZE .................................	35
Changes in Displayed Frequencies..................	36
TRANSMITTING .....................................................	37
MICROPHONE PTT ...........................................	37
SELECTING OUTPUT POWER ........................	37
TIME-OUT TIMER (TOT) ...................................	38
INHIBITING TRANSMIT ....................................	38
MEMORY CHANNELS ...........................................	39
STORING DATA IN MEMORY...........................	39
Simplex Memory Channels ..............................	39
Split Memory Channels ....................................	40
RECALLING MEMORY CHANNELS ................	41
Selecting Channels Sequentially .....................	41
Temporary Frequency Changes ......................	41
MEMORY —> VFO TRANSFERS .....................	42
ERASING MEMORY CHANNELS .....................	43
CALL CHANNEL.................................................	43
Recalling Call Channel.....................................	43
Changing Call Channel Contents (Simplex) ..	44
Changing Call Channel Contents (Split) ..........	45
CHANNEL DISPLAY FUNCTION ......................	45
INITIALIZING MEMORY.....................................	46
Partial Reset ....................................................	46
Full Reset .........................................................	46

OPERATING THROUGH REPEATERS ................	48
TRANSMIT OFFSETS .......................................	48
SELECTING OFFSET DIRECTION ..................	49
AUTOMATIC TRANSMIT OFFSET ...................	49
U.S.A. and Canada Versions ...........................	49
European Versions ..........................................	50
SELECTING OFFSET VALUES MANUALLY ..	50
REVERSE FUNCTION.......................................	51
TONE ACCESS .................................................	51
Selecting a Tone Frequency ............................	52
European Versions ..........................................	53
AUTOPATCH
(U.S.A. and Canada Versions) ..........................	53
Activating the Microphone Keypad...................	53
DUAL TONE MULTI-FREQUENCY
(DTMF) MEMORY ..............................................	54
Making DTMF Calls..........................................	54
Storing DTMF Numbers ...................................	54
Confirming Stored DTMF Numbers..................	55
Transmitting Stored DTMF Numbers ...............	55
SCAN ......................................................................	56
SCAN RESUME METHODS ..............................	57
Time-Operated Scan ........................................	57
Carrier-Operated Scan ....................................	57
SELECTING SCAN RESUME METHOD ..........	57
MEMORY SCAN ................................................	58
Locking-Out Memory Channels .......................	58
BAND SCAN ......................................................	59

PROGRAMMABLE BAND SCAN ......................	59
Setting Scan Limits...........................................	59
Using Programmable Band Scan ....................	60
CALLA/FO SCAN .............................................	61
CALLVMEMORY SCAN ...................................	61
AUXILIARY FUNCTIONS .......................................	62
LOCK .................................................................	62
Transceiver Lock ..............................................	62
Microphone Lock .............................................	62
AUTOMATIC POWER OFF (APO) ....................	63
BEEP TONE........................................................	64
DISPLAY DIMMER ............................................	64
DISPLAY MODE ................................................	65
DISPLAY DEMONSTRATION MODE ...............	66
REMOTE CONTROL..............................................	67
REMOTE FUNCTIONS USING
MC-45DM/DME ..................................................	68
Configuring the PF Keys ..................................	70
Monitor Function ..............................................	70
REMOTE FUNCTIONS USING TH-7 ...............	71
KEYPAD DIRECT ENTRY ................................	71
Frequency Entry ..............................................	71
Memory Channel Entry ....................................	73
CONTINUOUS TONE CODED SQUELCH SYSTEM
(CTCSS) .................................................................	74
SELECTING CTCSS FREQUENCIES ..............	74
USING CTCSS ...................................................	74

DUAL TONE SQUELCH SYSTEM (DTSS) ...........	75
ACTIVATING DTSS ...........................................	75
STORING DTSS CODES ..................................	76
DTSS AND REPEATERS ..................................	76
MESSAGE PLAYBACK CONTROL
VIA DTSS ...........................................................	77
Setting Message Playback DTSS Code ..........	78
PAGE .....................................................................	79
OVERVIEW ........................................................	79
PAGE CODE MEMORY ....................................	79
STORING PAGE CODES ..................................	79
CALLING ...........................................................	81
RECEIVING .......................................................	82
Receiving a Call with your Station Code.........	82
Receiving a Call with a Group Code ...............	82
PAGE ANSWER-BACK .....................................	83
PAGE CODE AND REPEATERS ......................	83
LOCKING-OUT CODES ....................................	84
AUTO PAGE CANCEL ......................................	84
OPEN PAGE ......................................................	85
TONE ALERT..........................................................	86
ACTIVATING TONE ALERT ..............................	86
CHANGING THE ALARM TONE .......................	87
MESSAGE RECORDING.......................................	88
ACTIVATING THE RECORD FUNCTION .........	88
SELECTING THE RECORDING TIME .............	88
SELECTING THE RECORDING MODE ...........	89

IV

PLAYBACK ........................................................	90
FULL DUPLEX OPERATION ..................................	91
PACKET OPERATION ...........................................	93
ENABLING THE DATA CONNECTOR ..............	93
MAINTENANCE .....................................................	94
GENERAL INFORMATION ................................	94
SERVICE.............................................................	94
SERVICE NOTE ................................................	95
CLEANING .........................................................	95
TROUBLESHOOTING ...........................................	96
OPTIONAL ACCESSORIES ..................................	102
INSTALLING OPTIONS .........................................	104
OPENING THE TRANSCEIVER .......................	104
INSTALLING THE TSU-8 CTCSS UNIT ...........	104
INSTALLING THE ME-1 EXPANSION
MEMORY UNIT................................................	105
SPECIFICATIONS ...............................................	106
GLOSSARY............................................................	108
QUICK REFERENCE GUIDE ................................	115

FEATURES

•Dual band receive capability on each model in the series:

TM-251A/E: 144 MHz plus 430/440 MHz TM-451A/E: 430/440 MHz plus 144 MHz

•Full Duplex allows “telephone-style" contacts; Transmit on the Main band with simultaneous Receive on the Sub-band.

•Digital Record extends the convenience of CTCSS, DTSS, Page, and Tone Alert by recording the audio of a station calling you.

•DTSS and Page allow selective calling of specific stations. In addition, combining Tone Alert with Page lets you know who called and when.

•Innovative Menu Set-up method combines sophisticated features with simple operation; ergonomic design places only the most frequentlyused keys on the Front Panel without losing desired features.

ACCESSORIES

	Accessory	Part Number	Quantity
	Microphone
	U.S.A., Canada, General’	T91-0517-XX	1
	Europe, General’	T91-0516-XX	1
	DC power cable	E30-2111-XX	1
	Fuse
	TM-251: 15 A	F51-0017-XX	1
	TM-451: 10 A	F51-0016-XX	1
	Mounting bracket	J29-0614-XX	1
	Stacking plate	J21-4469-XX	1 set
	Screws	N99-0384-XX	1 set
	Wrench	W01-0426-XX	1
	Warranty card	—	1
	(U.S.A., Canada, Europe^)
	Instruction manual	B62-0455-XX	1

’ Excluding some General market versions.

^ Excluding some European versions.

CONVENTIONS FOLLOWED IN THIS

MANUAL

The writing conventions described below have been followed to simplify key stroke instructions and avoid unnecessary repetition. This format is less confusing for the reader. Reviewing the following information now will reduce your learning period. That means less time will be spent reading this manual; more time will be available for operating.

Note: Basic procedures are numbered sequentially to guide you step-by- step. Additional information pertaining to a step, but not essential to complete the procedure, is provided in bulleted form following many steps for further guidance.

INSTRUCTION	MEANING	WHAT TO DO
Press	Press the key.	Press and release
[KEY].		KEY.
Prpqc;	Press the keys	Press and hold
[KEY1] + [KEY2].	simultaneously.	KEY1 down, then
		press KEY2.
Prpcq	Press the keys	Press KEY1
[KEY1], [KEY2].	in sequence.	momentarily,
		release KEY1,
		then press KEY2.
Press	Press the key	With the
[KEY]+ POWER ON.	while powering	transceiver power
	the transceiver.	OFF, press and
		hold KEY, then
		turn ON the
		transceiver power
		by pressing
		[PWR].
Press	Press the	Press and hold
[F] (1 s).	Function key for	the Function key
	longer than 1	until the "F"
	second.	indicator on the
		Display begins
		flashing.
Press	Press the key	Press and hold
[KEY] (1 s).	for longer than	KEY until the
	1 second.	function begins.

PREPARATION FOR MOBILE OPERATION

When operating mobile, do not attempt to configure your transceiver or change Menu settings while driving because it is simply too dangerous. Stop the car first, then make the necessary changes. Also, be aware of local laws pertaining to the use of headphones/headsets while driving on public roads. If in doubt, do not wear headphones while mobiling.

MOBILE INSTALLATION

Install the transceiver in a safe, convenient position inside your vehicle that minimizes danger to your passengers and yourself while the vehicle is in motion. For example, consider installing the transceiver under the dash in front of the passenger seat so that knees or legs will not strike the transceiver during sudden braking of your vehicle. Try to pick a well-ventilated location that is shielded from direct sunlight.

Installation Example

1Install the mounting bracket using the supplied flat washers and self-tapping screws. There are 4 washers and 4 screws supplied.

•The bracket can be mounted with the bracket opening for the transceiver facing down for underdash mounting, or with the opening facing up.

•If mounted underdash, the bracket must be installed so that the 3 screw holes on the edge of each bracket side are facing forward. This allows you to mount the transceiver horizontally or to angle it upward.

•If mounted with the bracket opening facing upward, position the bracket with the 3 holes facing forward to angle the transceiver upward. Position the bracket with the 3 holes facing the rear if you plan to angle the transceiver downward. The transceiver can be mounted horizontally, angled neither up nor down, with the bracket positioned either way.

2Position the transceiver in the bracket to determine the best viewing angle.

3Insert and tighten the supplied hexagon SEMS screws and washers. There are 2 screws and

2 washers supplied for each side of the bracket.

• Double check that all hardware is tightened to prevent vehicle vibration from loosening the bracket or transceiver.

Mounting bracket

liiSl

A 3EE1

SEMS screws <

Stacking plate-'

DC POWER CABLE CONNECTION

Route the DC power cable supplied with the transceiver, or an optional DC cable equipped with a noise filter, directly to the vehicle’s battery terminals using the shortest path from the transceiver. If using a noise filter, it should be installed with an insulator to prevent it from touching metal on the vehicle. It is not recommended to use the cigarette lighter socket since some cigarette lighter sockets introduce an unacceptable voltage drop.

Passenger compartment

I'Joise filter supplied with PG-3B

Power supply connector

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

	,Red ( + ) Fuse holders
Vehicle chassis	with 20 A fuses

Black ( - )

Engine compartment

Double check cable connections at the battery to confirm correct polarities (Red ^ Positive, Black ^ Negative).

Dismantle fuse holder.

Passenger compartment

To prevent the risk of short circuits, disconnect other wiring from the negative { —) battery terminal before connecting the transceiver. Confirm the correct polarity of the connections before attaching the power cable; red connects to the positive ( +) terminal, black connects to the negative ( —) terminal. Use the full length of the cable without cutting off excess even if the cable is longer than required. In particular, never remove the fuse holders from the cable. After completing transceiver connections to the battery, then reconnect any wiring removed from the negative terminal.

If the power cable must be routed through a hole in the vehicle chassis or body, for example in the firewall at the front of the passenger compartment, use a rubber grommet to protect the cable from abrasion. The entire length of the cable must be dressed so it is isolated from heat and moisture. After the cable is in place, wind heatresistant tape around the fuse holder to protect it from moisture. Tie down the full run of cable.

The vehicle battery must have a nominal rating of 12 V. Never connect the transceiver to a 24 V battery. Be sure to use a 12 V vehicle battery that has sufficient current capacity. If the current to the transceiver is insufficient, the Display may darken during transmission, or transmit output power may drop excessively.

Only after completing the installation, connect the transceiver’s power supply connector to the DC power cable. Press the connectors firmly together until the locking tab clicks.

Replacing Fuses

If the fuse blows, determine the cause then correct the problem. After the problem is resolved, then replace the fuse. If newly installed fuses continue to blow, disconnect the power cable and contact your dealer or nearest Service Center for assistance.

	Fuse Location	Fuse Current Rating
	TM-251A/E	15 A
	TM-451A/E	10 A
	Supplied Accessory	20 A
	DC Power Cable

CAUTION: Only use fuses of the specified type and rating.

Note: If you use the transceiver for a long period when the vehicle battery has not been fully charged, or when the engine has been stopped, the battery may become discharged, and will not have sufficient reserves to start the vehicle. Avoid using the transceiver under these conditions.

ANTENNA CONNECTION

Before operating mobile, you must first install an efficient, well-tuned antenna. The success of your mobile installation will depend largely on the type of antenna and its correct installation. The transceiver can give excellent results if the antenna system and its installation is given careful attention.

Your choice of antenna should have a 50 ohm impedance to match the transceiver input impedance. Use low-loss coaxial feed line that also has a characteristic impedance of 50 ohms. Coupling the antenna to the transceiver via feed lines having an impedance other than 50 ohms reduces the efficiency of the antenna system, and can cause interference to nearby broadcast television receivers, radio receivers, and other electronic equipment.

ANT connector Feed line connector

CAUTION: Transmitting without first connecting an antenna or other matched load may damage the transceiver. Always connect the antenna to the transceiver before transmitting.

PREPARATION FOR FIXED STATION OPERATION

The following diagram illustrates how to make connections to the rear panel of the transceiver.

Connect all cables securely so they will not come loose if pulled.

DC POWER SUPPLY CONNECTION

In order to use this transceiver for fixed station operation, you will need a separate 13.8 V DC power supply that must be purchased separately. DO NOT directly connect the transceiver to an AC outlet! Use the supplied DC power cable to connect the transceiver to a regulated power supply. Do not substitute a cable with smaller gauge wires.

The following table lists the current capacity recommended for power supplies used with each type of transceiver.

Transceiver Model	Power Supply Capacity
TM-251A/E	11 A or more
TM-451A/E	10 A or more

First connect the DC power cable to the regulated DC power supply and check that polarities are correct (Red: positive, Black: negative). Then connect the transceiver’s DC power connector to the connector on the DC power cable. Press the connectors firmly together until the locking tab clicks.

Note:

►For your transceiver to fully exhibit its performance capabilities, the following optional power supply is recommended:

PS-33 (20.5 A. 25% duty cycle).

►Before connecting the DC power supply to the transceiver, be sure to switch the transceiver and the DC power supply off.

►Do not plug the DC power supply Into an AC outlet until you make all connections.

■Replacing Fuses

If the fuse blows, determine the cause then correct the problem. After the problem is resolved, only then replace the fuse. If newly installed fuses continue to blow, disconnect the power plug and contact your dealer or nearest Service Center for assistance.

Fuse Location	Fuse Current Rating
TM-251A/E	15 A
TM-451A/E	10 A
Supplied Accessory	20 A
DC Power Cable

CAUTION: Only use fuses of the specified type and rating.

ANTENNA CONNECTION

The type of the antenna system, consisting of the antenna, ground, and feed line, will greatly affect the successful performance of the transceiver. Use a properly adjusted 50 ohm antenna of good quality designed for operation at your operating frequency to let your transceiver perform at its best.

Install low-loss 50 ohm coaxial cable and a first quality connector for the connection to the transceiver. For longer feed line runs, especially for operation at UHF frequencies, you might consider investing in "hardline" transmission line. Flardline is available in larger diameters and has much lower loss than coaxial cable. The lower loss can make a significant difference for those interested in weak signal operation. In all cases, match the impedance of the feed line and antenna so that the SWR is minimum. Generally, an SWR measurement of 1.5:1 or less is considered satisfactory. All connections must be clean and tight. Coupling the antenna to the transceiver via feed line having an impedance other than 50 ohms reduces the efficiency of the antenna system. It also can cause interference to nearby broadcast television receivers, radio receivers, and other electronic equipment.

CAUTION:

►All fixed stations should be equipped with a lightning arrester to reduce the risk of fire, electric shock, and transceiver damage.

►Transmitting without first connecting an antenna or other matched load may damage the transceiver. Always connect the antenna to the transceiver before transmitting.

ACCESSORY CONNECTIONS

EXTERNAL SPEAKER

Use an external speaker with 8 ohms impedance. The jack accepts a 3.5 mm diameter mono (2-conductor) plug. Recommended speakers include the SP-50B and SP-41. Connecting an external speaker automatically cuts off audio to the internal speaker.

MICROPHONE

To communicate in the voice modes, plug a 600 ohm microphone equipped with an 8-pin modular connector into the modular socket on the Front Panel of the transceiver. Press firmly on the plug until the locking tab clicks.

Microphone modular socket

PACKET EQUIPMENT

If you intend to use this transceiver for Packet operation, you will need the following equipment:

•Personal computer with communications software (Alternatively, a "dumb" terminal capable of sending ASCII commands)

•TNC (Terminal Node Controller)

•TNC power supply

•RS-232C cable

•6-pin mini DIN plug (PG-5A)

Refer to the accompanying diagram and the associated instruction manuals to configure the equipment as shown. Connect your TNC to the DATA connector on the transceiver Rear Panel using a cable equipped with a 6-pin mini DIN plug. Do not share a single power supply between the transceiver and the TNC. Keep as wide a separation between the transceiver and computer as practical to reduce noise-pickup by the transceiver.

DATA Connector Pinout

Personal computer/dumb terminal

	Pin	Pin	Function
	Number	Name
			Packet data input
	1	PKD	• Transmit data from TNC to
			transceiver
	2	DE	Ground for PKD
			Packet standby
	3	PKS	• TNC can use this pin to
			inhibit the transceiver
			microphone input while
			transmitting packet signals.
	4	9600D	Detects 9600 bps data.
	5	1200D	Detects 1200 bps data.
			Squelch control output
	6	SQC	• Inhibits TNC data transmit
			while transceiver squelch is
			open.

10

GETTING ACQUAINTED

The following sections describe basic functions of the Front Panel controls and buttons, Rear Panel jacks and connectors, microphone buttons and Display indicators. For full explanations of functions mentioned, refer to the appropriate section elsewhere in the manual.

FRONT PANEL

®(D

12

YOUR FIRST QSO

If you tend to discard instruction manuals along with the packaging material....please don’t. The 5 steps below will get you on the air in your first QSO within minutes to allow you to experience the exhilaration that comes with opening a brand new transceiver.

After trying the rig for a while, settle back in your most comfortable operating chair with this manual and your favorite drink for an hour or two. The time spent will be worthwhile.

1Connect a 13.8 V DC power source to the power connector, and a suitable antenna to the antenna connector.

2Turn the VOL and SQL controls to approximately 9 o’clock.

3Press [PWR].

•The default frequency appears on the Display.

4 Turn the Tuning control to select a frequency.

5If accessing a repeater, press [SHIFT] to select a standard positive transmit offset. Repeat to select a negative offset.

•Either" +" or" -" appears.

•If a subaudible tone is required to access the repeater:

a)Press [F], [TONE/CTCSS].

b)Turn the Tuning control to select a Tone frequency.

c)Press [TONE/CTCSS] to exit from Tone Select.

d)Press [TONE/CTCSS] again to turn ON the TONE function.

6When the frequency is clear, press [PTT] and begin communicating.

•Release [PTT] to receive.

11

® VFO button

Provides the following 5 functions:

•VFO mode select {page 32}

•Menu function select (descending order) {page 22}

•VFO Scan {page 59}

•Memory/Call channel transfer to VFO {page 42}

•Partial reset {page 46}

(2)MR (Memory Recall) button

Provides the following 5 functions:

•Memory Recall select {page 41}

•Menu function select (ascending order) {page 22}

•Memory Scan {page 58}

•Memory Write {page 39}

•Full reset {page 46}

(DF (Function) button

Provides the following 3 functions:

•Multiple key function select

•Menu Set-up enter {page 22}

•Menu Set-up exit {page 22}

@ VOL (Volume) control

Adjusts the level of receive audio from the speaker {page 28}.

(DPWR (Power) switch

Switches the transceiver ON or OFF {page 28}. Also used in conjunction with other keys to access Menu B {page 24} or initialize the microprocessor and its memory {page 46}.

(DTUNING control

Provides the following 6 functions:

•Selects transmit/receive frequencies {page 32} and frequency limits {pages 33 and 59}.

•Selects memory channels in Memory Recall {page 41}.

•Selects available choices when configuring Menu functions {page 22}.

•Selects subaudible Tone frequency {page 52} and transmit offset {page 50}.

•Selects scan direction {page 58}.

•Selects DTSS/page codes {pages 76 and 79}.

13

® SHIFT button

Selects the transmit frequency offset with respect to the receive frequency {page 491. Also toggles Tone Alert ON or OFF {page 86).

(DTONE/CTCSS button

Switches Tone and CTCSS ON or OFF {pages 51 and 74). Also used for selecting the subaudible Tone frequency {page 52}.

d) REV (Reverse) button

Switches the transmit frequency and receive frequency when operating with a transmit offset or split frequency {page 51). Also toggles the transceiver between the Main band or the Sub-band (page 30}.

®DTSS button

Toggles DTSS and Page ON or OFF. Also used for setting the DTSS code and Page codes {page 75}.

©SQL (Squelch) control

Adjusts the squelch threshold level {page 28). This allows you to mute speaker output while no stations are being received.

©Microphone connector

Insert the 8-pin modular microphone plug until the locking tab "clicks".

C]

OWN

RD: Oo0f> squelch audio(100 mV/ 10 kfi)

MIC

GND (MIC)

STBY (Pm

GND

DC 8 V. 100 mA max.

UP

(© LOW button

Selects High, Mid, or Low transmit output power. Also activates Lock {page 62} and memory channel lock-out {page 58} functions.

14

1

REAR PANEL

-d)

® ANT connector

Connect an external antenna designed for operation on the same band as this transceiver. When making test transmissions, connect a dummy load in place of the antenna. The antenna system or load should have an impedance of 50 ohms. All models accept a male PL-259 coaxial plug except the TM-451E which accepts a male Type N plug.

(D DATA connector

Connect a Terminal Node Controller (TNC) for Packet operation. Accepts a 6-pin mini DIN plug. See page 10 for pinout details.

©Power Input DC 13.8 V connector

Connect a 13.8 V DC power source. Use the supplied DC power cable.

@ EXT. SP jack

Connect an optional external speaker for clearer audio. Accepts a 3.5 mm diameter (2-conductor) plug.

15

MICROPHONE

MC-45DM/45DME

©

©UP button

(D DWN button

Raises or lowers the VFO frequency, the memory channel number, the Tone/CTCSS frequency, the DTSS/Page code, or the Page memory number. Holding either button down causes the action to be repeated, and "fuzzy" logic increases the rate of repetition with time. Also, in Menu Set-up, switches among available menu selections for each menu function.

® PTT (Push-to-talk) switch

Press to transmit; release to receive. Also, press to exit Scan and Menu Set-up functions, DTSS/Page code setting, or Tone/CTCSS frequency setting.

© LOCK switch

Locks all microphone functions except [PTT] and the DTMF keypad, if equipped.

® PF (Programmable Function) key

Activates the Monitor function to open and close the squelch regardless which squelch system is being used. The key function can be re-programmed, if desired {page 70}, On European versions, activates the

1750 Hz tone for repeater access.

(DCALL key, 1750 key

Recalls the Call channel. Pressing for more than

1 second initiates a Call Scan. The Call function can be re-programmed, if desired (page 70}. On European versions, sends a 1750 Hz tone for repeater access.

©VFO key, MR key

Identical to the Front Panel functions of the same name. Both functions can be re-programmed, if desired

{page 70}.

(D DTMF keypad (some versions only)

The 16-key keypad is used to transmit DTMF tones.

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DISPLAY

® (D (D ®

LOCK\+V+U :L0W

....

DUP/^nnO O O

CO

S»RF 1 3 5 7

©LOCK

Indicates the Lock function is ON; most Front Panel and microphone buttons and keys are locked {page 62}.

Indicates AM receive mode is ON. Blinks while accessing Menu A, AM/FM Mode {page 23}. AM/FM mode is available only on some versions of the TM251A/E {page 31}.

MID i REV/—\— +;■< O O O O O O O:

^ V# Ct O 0.0 O 0.0;

	APO
	DIM PAG
	. w* -iSEEP-----------
	DTSS
	; U l.fSTEP TONE
9 OVER	‘ U m U ^ T O T CTCSS

©LOW, MID

Indicates Low or Mid transmit output power is selected (page 37). When "LOW" or "MID" are not visible, High output power is selected.

©REV

Indicates the Reverse function is ON {page 51}. Transmit and receive frequencies are reversed.

(D +v +u

Indicates the 144 MHz Sub-band (" +V") or 430/440 MHz Sub-band (" +U") is selected {page 30}.

(DQ

Appears when [F] is pressed. Indicates that alternate functions of multiple-function buttons can be accessed now.

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		® (D (D ® (S)
L0CK:+V+U :L0W MID:	REV/- r.:^ilk		O it ó Q O O:
r^!3|Q[i0i			U $I,U Q U,U:
DUP/ Wi n O O U C<Wg2			nii / APÓ
			DIM------' PAG
CO	nil	,«-«BEEP		DTSS
i¿»cttfiw nilfcva I		^ W	M^TEP	TONE
SARF	OVER	3:LI«S.fWTOT CTCss

@ - - +

Indicates the transmit frequency is offset (different) from the receive frequency {page 49}. The symbol displayed indicates the direction that the transmit frequency is offset from the receive frequency. Also indicates a splitfrequency memory channel is selected (page 41}. " blinks while Menu A, Transmit Offset is selected

{page 23}.

Indicates Tone Alert is ON {page 86}. When using Tone Alert, blinks after receipt of a signal. Also blinks while Menu A, Tone Alert Alarm Tone is selected

{page 23}.

Indicates the selected memory channel is locked-out {page 58}.

MENU

Blinks while accessing Menu A {page 23}. Remains ON while accessing Menu B {page 24}.

® DIM

Blinks when selecting the level of Display illumination in Menu A, Display Brightness {page 23}.

This indicator is not currently used.

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LOCK: +V +U : LOW MID! REV/--------------------	+/.^ O Q O O O O O:
r«	Wi	. { m m Apo
DUP.ijWm O O O O		DIM PAG
CO ! ItldO.Cl.O OMB		-¿ii-BEEP DTSS

Ufcy»lM IslIkIM■ ■ ■ ■ ■ ■ ■ ■ ■ llll ElZi 'V P ^TEP TON E
SARF	1 3 5 7 9 OVER EUD ;!.l« £ff«TOT CTCSS

DUP

Indicates Full Duplex mode is ON {page 91}. Blinks while accessing Menu A, Full Duplex {page 23}.

®CO

Indicates Carrier-operated Scan Resume is ON {page 57}. When not visible, Time-operated Scan Resume is in effect. Blinks while accessing Menu A, Scan Resume {page 23}.

Indicates S-meter squelch is ON {page 29}. Blinks while accessing Menu A, S-meter Squelch {page 23}.

® liilkUi

Indicates the squelch is open due to a receive signal or noise that is greater in strength than the noise squelch threshold level {page 28}. Also appears when the noise squelch is set to minimum by turning the SQL control fully counterclockwise. If using either CTCSS or DTSS, indicates the squelch is open due to a received signal that contains a CTCSS tone or DTSS code that matches the tone or code programmed in your transceiver.

ntip

®ISSOXLO uM

Displays the transmit/receive frequency, frequency step {page 35}, and Tone frequency {page 52}. Also displays the available selections when using Menu Set-up {page 22}. The decimal point blinks while the transceiver is scanning {page 59}.

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In Receive, acts as an S-meter to indicate the signal strength of received signals. In Transmit, acts as an RF power meter to indicate the relative transmit output power {page 37}. Full scale represents High transmit power.

Indicates the transceiver is in Transmit mode with a transmit frequency that is within the transmit band.

:0 O ':

Displays the currently selected memory channel number {page 41} or Menu B number {page 24}. The dots beside the memory channel numbers are used only by the ME-1 Expansion Unit. The right dot appears when the 100s digit of the channel number is 1 (memory channels 100-199). The left dot appears when the 100s digit of the channel number is 2 (memory channel 200).

Indicates the Time-out Timer is ON {page 38}. Blinks while accessing Menu A, Time-Out Timer {page 23}.

® STEP

Blinks while accessing Menu A, Frequency Step {page 23}.

@ BEEP

Blinks while accessing Menu A, Confirmation Beep {page 23}.

Acts as a Sub-display to show receive frequency. Tone frequency, etc.

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LOCKiJfV+u’rLOw 'WDi REV/--			0
	--- ------------------------------		y tf.tf V !J^U:
DUP	n 'U O O U'nip		^.\ssm APo-
			Hw DIM PAG
CO /			..-—-—-BEEP DTSS
UM»T isiiiaM I		II	iJsTEP TONE
	SARF		ER ESo :Lh LUTOT CTCSS

© APO

Indicates Automatic Power Off is ON {page 63}. Blinks while accessing Menu A, Automatic Power Off

(page 23}.

@ PAG

Indicates Page is ON (page 79}.

@ DTSS

Indicates the Dual Tone Squelch System is ON (page 75}.

@TONE

Indicates the subaudible Tone encoder is ON {page 52}.

(i) CTCSS

Indicates the Continuous Tone Coded Squelch System is ON when the CTCSS option (TSU-8) is installed

{page 74}.

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MENU SET-UP

MENU DESCRIPTION

Many functions on this transceiver are selected or configured via software-controlled menus instead of physical controls on the transceiver. Once familiar with the Menu system, you will appreciate the versatility it offers. No longer is the number and complexity of features restricted by the physical size of transceiver.

The Menus are identified as Menu A and Menu B. Menu A is used to access functions that are frequently changed while Menu B is used for less frequently changed functions.

MENU A ACCESS

Anytime that you want to change a function that is controlled by Menu A, use the following procedure:

1 Press [F] (1 s) to enter Menu A.

• "MENU" begins blinking and the menu selected last appears.

2 Select the desired menu function by pressing either [MR] or [VFO].

•Press [VFO] to cycle through functions in a downward direction on the chart.

•Press [MR] to cycle through functions in an upward direction on the chart.

Microphone [MR] or [VFO] may be used if more convenient.

Select the desired menu selection by turning the Tuning control or by pressing microphone [UP] or [OWN].

When selecting from a group of numeric menu selections, turning the Tuning control clockwise or pressing microphone [UP] selects in ascending order, and turning the Tuning control counterclockwise or pressing microphone [OWN] selects in descending order.

4After selecting the desired menu selection, press [SHIFT] or [TONE/CTCSS] or [REV] or [DTSS] to exit Menu A.

Note: The Automatic Power Off timer stops counting while you are

in Menu Set-up.

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MENU A CONFIGURATION

Menu	Description	Selections		Default	Page
Label
DIM	Display Brightness	OFF/d4/d3/d2/d1		d2	64
	• 5 illumination levels (d1: brightest)
BEEP	Confirmation Beep	OFF/ON		ON	64
STEP	Frequency Step Size	12.5kHz/25kHz/5kHz/		TM-251A/E: 12.5 kHz’	35
		10kHz/15kHz/20kHz		TM-451A/E: 25 kHz
TOT	Time-Out Timer	OFF/3/5/10/20/30		OFF	38
		minutes
APO	Automatic Power Off	OFF/60/120/180		OFF	63
		minutes
DUP	Full Duplex	OFF/ON		OFF	91
CO	Scan Resume	TO/CO		TO	57
S.SQL	S-meter Squelch	OFF/ON		OFF	29
+ —	Transmit Offset (Shift)	d, 5 kHz to 40 MHz		d^	50
	Tone Alert Alarm Tone	Bel1/Bel2/Bel3		Bell	87
	Display Mode during CTCSS, DTSS, or Page	OFF/Sub1/Sub2		OFF	65
A	AM/FM Mode^	A/F		FM (AM: 118 to 136 MHz)	31

^ TM-251A (U.S.A. and Canada): 5 kHz

2 TM-251A/E: 600 kHz. TM-451A: 5 MHz, TM-451E; 1.6 MHz

^ Only on Main Band of TM-251A/E with expanded receive coverage outside the Amateur bands.

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