KENWOOD TM-461A (01) PDF Document

The KENWOOD TM-461A transceiver includes the following features:

• **Memory Indexing:** Conveniently allows you to assign names to memory channels. You can use callsigns, repeater names, cities, persons’ names, etc.

• **In Memory Recall mode:** Memory channel numbers can be displayed instead of frequencies if you choose.

• **Innovative Menu Set-up method:** Combines sophisticated features with simple operation; ergonomic design places only the most frequently-used keys on the Front Panel without losing desired features.

• **Dual Tone Squelch System (DTSS):** Allows selective calling of specific stations.

• **Programmable with a RX Tone and TX Tone separately:** This enhances the optional Continuous Tone Coded Squelch System (CTCSS).

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

• When operating mobile, do not attempt to configure your transceiver while driving because it is simply too dangerous.

• 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.

• 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 KENWOOD documentation.

• Do not expose the transceiver to long periods of direct sunlight nor place the transceiver close to heating appliances.

• Do not place the transceiver in excessively dusty areas, humid areas, nor 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.

The writing conventions described below have been followed to simplify instructions. Most procedures require that you press an appropriate key in each step within approximately 10 seconds, or the previous mode will be restored.

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. Consider installing the transceiver under the dash in front of the passenger seat. Try to pick a well-ventilated location that is shielded from direct sunlight.

Installation Steps:

1. Install the mounting bracket in the vehicle using the supplied flat washers and self-tapping screws. There are 4 washers and 4 screws supplied. The bracket can be mounted with the opening 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 forward.

• If mounted with the bracket opening facing upward, position the bracket with the 3 holes facing the rear to angle the transceiver upward. Position the bracket with the 3 holes facing forward if you plan to angle the transceiver downward.

2. Position the transceiver, then insert 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.

The vehicle battery must have a nominal rating of 12 V. Never connect the transceiver to a 24 V battery.

1. Route the DC power cable supplied with the transceiver directly to the vehicle’s battery terminals using the shortest path from the transceiver.

• It is not recommended to use the cigarette lighter socket due to potential voltage drop.

• If the power cable must be routed through a hole in the vehicle chassis, use a rubber grommet to protect the cable from abrasion.

2. After the cable is in place, wind heat-resistant tape around the fuse holder to protect it from moisture. Tie down the full run of cable.

3. To prevent short circuits, disconnect other wiring from the negative (-) battery terminal before connecting the transceiver.

4. Confirm the correct polarity and attach the power cable to the battery terminals: red connects to the positive (+) terminal, black connects to the negative (-) terminal. Use the full length of the cable without cutting off excess. Never remove the fuse holders from the cable.

5. Reconnect any wiring removed from the negative terminal.

6. Connect the DC power cable to the transceiver’s power supply connector. Press the connectors firmly together until the locking tab clicks.

For fixed station operation, you will need a separate 13.8 V DC power supply (purchased separately). For the TM-461A, a power supply with a capacity of 10 A or more is required.

1. Connect the DC power cable to the regulated DC power supply and check that polarities are correct (Red: positive, Black: negative). DO NOT directly connect the transceiver to an AC outlet!

• Use the supplied DC power cable.

• Do not substitute a cable with smaller gauge wires.

2. 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: Before connecting the DC power supply to the transceiver, be sure to switch both the transceiver and the DC power supply OFF. Do not plug the DC power supply into an AC outlet until you make all connections.

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.

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

Before operating, you must install an efficient, well-tuned antenna. Your choice of antenna should have a 50 Ω impedance to match the transceiver input impedance. Use low-loss coaxial feed line that also has a characteristic impedance of 50 Ω.

CAUTION:

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

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

External Speaker:

If you plan to use an external speaker, choose one with an impedance of 8 Ω. The external speaker jack is on the rear panel and accepts a 3.5 mm diameter mono (2-conductor) plug.

Microphone:

To communicate in voice modes, plug a 600 Ω 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.

• VFO button: Selects the VFO mode. The Tuning control changes the frequency in this mode. Also used for Menu selection and starting/stopping VFO or Program Scan.

• MR button: Selects the Memory Recall mode. The Tuning control changes the memory channel in this mode. Also used for starting/stopping Memory Scan.

• Tuning control: Selects transmit/receive frequencies in VFO mode and memory channels in Memory Recall mode. Also used for Menu selection, setting Program Scan limits, changing scan direction, and selecting DTSS code.

• VOL control: Adjusts the level of receive audio from the speaker.

• MN button: Selects the Memory Name mode.

• POWER switch: Switches the transceiver ON or OFF.

• SQL (Squelch) control: Adjusts the squelch threshold level to mute speaker output when no stations are being received.

• Microphone connector: 8-pin modular connector for the microphone.

• MHz button: Selects the MHz mode, allowing frequency changes in 1 MHz steps.

• F (Function) button: Allows you to select the different functions that are available on multifunction buttons.

• TONE button: Switches the Tone function ON or OFF. With the optional TSU-8 installed, it also switches the CTCSS function ON or OFF.

• REV (Reverse) button: Switches the transmit and receive frequencies when operating with a transmit offset or a split memory channel.

The microphone functions are as follows (features may vary between MC-53DM and MC-45 models):

• UP/DWN buttons: Raises or lowers the VFO frequency, memory channel number, Tone/CTCSS frequency, or DTSS code. Holding either button down causes the action to be repeated.

• PTT (Push-to-talk) switch: Press to transmit; release to receive. Also used to exit various functions like Scan or DTSS code select.

• LOCK switch: Locks all microphone functions except [PTT] and the DTMF keypad (if equipped).

• CALL key: Recalls the Call channel. Pressing for more than 1 second initiates the Call/VFO Scan or Call/Memory Scan.

• VFO key / MR key: Identical to the Front Panel functions of the same names. Can be re-programmed.

• PF key: A programmable function key. Its function differs depending on the selection in Menu B.

• DTMF keypad (MC-53DM only): The 16-key keypad is used with DTMF functions, or to directly enter a frequency or memory channel number.

• Key icon: Indicates the Transceiver Lock function is ON.

• – +: Indicates the transmit frequency is offset from the receive frequency.

• R: Indicates the Reverse function is ON.

• T / CT: “T” indicates the Tone encoder is ON. “CT” indicates the CTCSS function is ON (requires optional TSU-8).

• DT: Indicates the Dual Tone Squelch System (DTSS) is ON.

• CO: Indicates Carrier-Operated Scan Resume is ON. When not visible, Time-Operated Scan is in effect.

• MENU: Visible while accessing Menu A or Menu B.

• Frequency Display: Shows frequency, step size, offset, and other data. The 1 MHz decimal point blinks during scanning.

• Channel Number Display: Shows the currently selected memory channel number.

• Star icon (★): Indicates the selected memory channel is locked-out from scanning.

• Spade icon (♠): (On some versions) Indicates AM receive mode is ON.

• TOT: Indicates the Time-out Timer function is ON.

• APO: Indicates the Automatic Power Off function is ON.

• L / M: Indicates whether Low (L) or Medium (M) transmit power is selected. No indicator means High power is selected.

• F: Appears when the [F] button is pressed, indicating alternate button functions can be accessed.

• BUSY: Indicates the squelch is open and the frequency is “busy”.

• S-meter/Power Meter: Bar graph that indicates received signal strength or relative transmit output power.

• ON AIR: Indicates the transceiver is in Transmit mode.

Switching Power ON/OFF:

1. If in a fixed station, switch ON the DC power supply.

2. Press the POWER switch to switch ON the transceiver.

3. To switch OFF, press the POWER switch again.

Adjusting Volume:

Turn the VOL control clockwise to increase the audio level and counterclockwise to decrease the level.

Adjusting Squelch:

The purpose of squelch is to silence audio output when no signals are present. Turn the SQL control clockwise until the background noise just disappears. You will then hear sound only when a station is being received.

Using the Tuning Control:

1. Press [VFO] to select VFO mode.

2. Turn the Tuning control to select a receive frequency.

• Clockwise rotation increases the frequency one step at a time.

• Counterclockwise rotation decreases the frequency one step at a time.

Using the Microphone [UP]/[DWN] Buttons:

Press [UP] or [DWN] once to change the receive frequency by one frequency step. Pressing and holding either button causes the frequency to step repeatedly.

Using the Microphone Keypad (MC-53DM only):

You can also enter frequencies directly using the keypad. This requires setting the microphone [PF] key to “ENTer” via Menu B.

Transmitting:

When ready to begin transmitting, press and hold the microphone [PTT] switch and speak in a normal tone of voice. Speaking too close to the microphone, or too loudly, may increase distortion.

Selecting Output Power:

It’s wise, and required by law, to select the lowest power that allows reliable communication. To select the transmit power you require, press [F], then [MN]. Each time this key operation is repeated, the transmit power changes as shown below:

High (No Indicator) → Medium (“M”) → Low (“L”)

The transmit power cannot be changed while transmitting.

Many functions on this transceiver are configured via software-controlled menus: Menu A for frequently changed functions and Menu B for less frequently changed functions.

To access Menu A:

1. Press [F] (1 s).

To access Menu B:

1. With the transceiver off, press and hold [F] while pressing POWER ON.

Navigating the Menus:

2. Select the desired menu function by turning the Tuning control or by pressing the microphone [UP]/[DWN] buttons.

3. The method for changing the setting differs:

• To toggle between two or three selections, press [VFO].

• To select from more than three selections, press [VFO], then turn the Tuning control or use the microphone [UP]/[DWN] buttons.

4. Press [F] or microphone [PTT] to exit the menu.

Note: If no action is taken for approximately 10 seconds, the transceiver automatically exits the menu.

To operate through a repeater, you need to set the receive frequency, the offset frequency, and the offset direction. Some repeaters also require a subaudible tone.

Flow Chart for Repeater Access:

1. Select a receive frequency: Tune to the repeater’s output frequency.

2. Select an offset frequency: Press [F] (1 s) to access Menu A. Select “O.S” and set the required offset (e.g., 5 MHz). Press [F] to exit.

3. Select an offset direction: Press [F], then [SHIFT] to cycle between simplex (no indicator), “+” (positive offset), and “-” (negative offset).

4. Activate the Tone function (if necessary): Press [TONE] until “T” appears on the display.

5. Select a Tone frequency (if necessary): Press [F] (1 s) to access Menu A. Select “TO” and choose the required tone frequency. Press [F] to exit.

6. Transmit: Press the microphone [PTT].

The default standard offset for the TM-461A is +5 MHz or -5 MHz (China: +10 MHz or -10 MHz).

You can store frequencies as either simplex (transmit and receive frequencies are the same) or split (transmit and receive frequencies are different).

Storing Simplex Memory Channels:

1. Select the desired frequency and associated data (Tone, CTCSS, etc.) using VFO mode.

2. Press [F] to enter Function Select mode. “F” and a memory channel number appear.

3. Turn the Tuning control or press microphone [UP]/[DWN] to select the desired memory channel.

4. Press [MR]. The data is stored in the memory channel.

Storing Split Memory Channels:

1. Select the desired receive frequency and associated data.

2. Press [F].

3. Select the desired memory channel.

4. Press [MR] (1 s). The “- +” icon appears.

5. Turn the Tuning control or press microphone [UP]/[DWN] to select the desired transmit frequency.

6. Press [MR]. The transmit frequency is stored, completing the split memory channel.

Note: You must execute each step within approximately 10 seconds or the previous mode will be restored.

Recalling Memory Channels:

1. Press [MR]. The memory channel used last is recalled.

2. Turn the Tuning control or use microphone [UP]/[DWN] to select the desired memory channel.

Erasing Memory Channels:

1. Press [MR] to select Memory Recall.

2. Select the memory channel you wish to erase.

3. Switch OFF the power to the transceiver.

4. Press and hold [MHz] while switching the POWER ON. The contents of the selected memory channel are erased. (Note: Memory channel 1 cannot be erased).

Naming Memory Channels:

You can assign a name of up to 6 characters to a memory channel.

1. Press [MR] to select Memory Recall.

2. Select the desired memory channel.

3. Switch OFF the power.

4. Press and hold [MN] while switching the POWER ON. The first digit of the name display blinks.

5. Turn the Tuning control or use microphone [UP]/[DWN] to select the first character.

6. Press [MN]. The second digit blinks.

7. Repeat steps 5 and 6 to enter up to 6 characters. Press [MHz], [F], [TONE], [REV], or [PTT] to complete the entry.

The transceiver offers several types of scanning. First, select a scan resume method (Time-Operated or Carrier-Operated) in Menu A under “SCN”.

• VFO Scan: Scans all frequencies on the band. In VFO mode, press [VFO] (1 s) to start or stop.

• Memory Scan: Scans all memory channels that contain data and are not locked out. In Memory Recall mode, press [MR] (1 s) to start or stop.

• Program Scan: Scans a specific frequency range you define. Set the scan limits in Menu B under “PGM.SCN”. To start, select a frequency within the limits and press [VFO] (1 s).

• Call/VFO Scan: Monitors the Call channel and the current VFO frequency. In VFO mode, press microphone [CALL] (1 s) to start or stop.

• Call/Memory Scan: Monitors the Call channel and the last used memory channel. In Memory Recall mode, press microphone [CALL] (1 s) to start or stop.

To reverse the scan direction during any scan, turn the Tuning control or press microphone [UP]/[DWN].

You can prevent memory channels that you prefer not to monitor from being scanned.

1. Press [MR] to select Memory Recall mode.

2. Select the memory channel to be locked out using the Tuning control or microphone [UP]/[DWN].

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

4. Select “MR.L” from the menu.

5. Press [VFO] to toggle the lockout status to ON. A star icon (★) appears, indicating the channel has been locked out.

6. Press [F] or microphone [PTT] to exit Menu A.

To cancel the lockout for a channel, repeat the procedure and toggle the status to OFF.

DTSS allows for selective calling using a 3-digit code (000-999).

Storing a DTSS Code:

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

2. Select “DT.C”. The current DTSS code appears.

3. If using the Tuning control: Press [VFO]. The first digit blinks. Use the Tuning control to select the digit. Repeat for the second and third digits, pressing [VFO] to move to the next digit and again to complete the selection.

4. If using the MC-53DM microphone keypad: Press [VFO]. The first digit blinks. Press the correct numeric keys to select the three digits.

5. Press [F] or [PTT] to exit the menu.

Using DTSS:

1. Store the appropriate DTSS code.

2. Press [F], then [DTSS]. The “DT” indicator appears when DTSS is ON.

• When you are called: The squelch of your transceiver opens only when the stored DTSS code is received.

• When you make a call: Press and hold microphone [PTT] to transmit your DTSS code. After establishing contact, you can switch the DTSS function OFF.

This function requires the MC-53DM microphone. You can store up to 16 digits in 10 dedicated DTMF memories (0-9).

Storing DTMF Numbers:

1. Access Menu B by pressing [F]+ POWER ON.

2. Select “DTMF.IN”.

3. Press [VFO]. The display for entering DTMF numbers appears.

4. Use the keypad to enter the digits of the number to be stored.

5. Press microphone [PF]. The display for selecting a memory channel appears.

6. Press a single key [0] ~ [9] to select a DTMF memory channel to store the number in.

7. Press [VFO] to exit.

Transmitting Stored DTMF Numbers:

1. Press microphone [PTT]+[PF]. The display for selecting a DTMF memory channel appears.

2. While holding [PTT], press a single key [0] ~ [9] to select a DTMF memory channel. The stored number will be transmitted.

There are two types of reset available.

Partial Reset (VFO):

This initializes all settings except the memory channels, the Call channel, and the Menu settings. To perform a partial reset, press and hold [VFO] while switching the POWER ON.

Full Reset (Memory):

This initializes all settings, including the VFO, memories, and Menu settings. Be aware that this will erase all your stored memory channel data.

1. To initialize all settings, press and hold [MR] while switching the POWER ON.

2. While the full display is visible, press [MR] again.

Note: After the display for the full reset appears, you must execute Step 2 within approximately 10 seconds or the reset will be aborted.

Choosing the correct step size is essential for selecting your exact receive frequency with the Tuning control or microphone buttons.

1. Select the VFO mode by pressing [VFO].

2. Access Menu A by pressing [F] (1 s).

3. Turn the Tuning control to select “F.S”.

4. Press [VFO] repeatedly to cycle through the available step sizes (e.g., 5, 10, 12.5, 15, 20, 25 kHz).

5. Press [F] to exit the menu and save the new step size.

The default step size for the TM-461A is 25 kHz.

These features can be toggled ON or OFF in Menu B.

• Time-Out Timer (TOT): Restricts a single transmission to a maximum time of 10 minutes. When TOT times out, the transceiver beeps and returns to Receive. To use, access “TOT” in Menu B and set it to ON.

• Busy Channel Lockout (BCL): Prevents you from transmitting on a channel that is already in use. Pressing [PTT] while the channel is busy will cause an audible warning tone and inhibit transmission. To use, access “BCL” in Menu B and set it to ON.

• Automatic Power Off (APO): Automatically turns the transceiver OFF after 3 hours of inactivity (no button presses or tuning). One minute before shutdown, “APO” starts blinking and warning tones sound. To use, access “APO” in Menu B and set it to ON.