KENWOOD TM-261A (01) PDF Document

The KENWOOD TM-261A has 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.

• The 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.

• It is programmable with a RX Tone and TX Tone separately. This enhances the optional Continuous Tone Coded Squelch System (CTCSS).

This manual covers the following models:

• TM-261A: 144 MHz FM transceiver (U.S.A./ Canada/ General market)

• TM-261EJ: 144 MHz FM transceiver (General market)

• TM-461A: 440 MHz FM transceiver (U.S.A./ Canada) and 430 MHz FM transceiver (China/ General market)

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.

¹ The MC-53DM and MC-45 microphones are sold as optional accessories also.

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. For example, consider installing the transceiver under the dash in front of the passenger seat so that knees or legs will not strike the radio during sudden braking of your vehicle. 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 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 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. The transceiver can be mounted horizontally, angled neither up nor down, with the bracket positioned either way.

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. 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.

1. Route the DC power cable supplied with the transceiver 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.

• If the power cable must be routed through a hole in the vehicle chassis or body, use a rubber grommet to protect the cable from abrasion. Dismantle the fuse holder to pass the cable through the firewall.

• The entire length of the cable must be dressed so it is isolated from heat and moisture.

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 the risk of short circuits, disconnect other wiring from the negative (-) battery terminal before connecting the transceiver.

4. Confirm the correct polarity of the connections, 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 even if the cable is longer than required. In particular, 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.

To use this transceiver for fixed station operation, you will need a separate 13.8 V DC power supply that must be purchased separately. The following table lists the recommended current capacity for power supplies:

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 to connect the transceiver to a regulated power supply.

• 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 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 or nearest Service Center for assistance.

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

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

Before operating, you must first install an efficient, well-tuned antenna. The success of your installation will depend largely on the type of antenna and its correct installation.

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. Coupling the antenna to the transceiver via feed lines having an impedance other than 50 Ω reduces the efficiency of the antenna system, and can cause interference to nearby broadcast television receivers, radio receivers, and other electronic equipment.

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 a speaker with an impedance of 8 Ω. The external speaker jack accepts a 3.5 mm diameter mono (2-conductor) plug. Recommended speakers include the SP-50B and SP-41.

Microphone

To communicate in the 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.

The front panel controls have the following functions:

1. VFO button: Selects the VFO mode. The Tuning control changes the transceiver frequency in this mode. Also provides:

• Menu A or Menu B selection of choices.

• VFO Scan start/stop to scan the entire VFO range.

• Program Scan start/stop to scan a programmed range of frequencies.

2. MR button: Selects the Memory Recall mode. The Tuning control changes the memory channel in this mode. Also provides Memory Scan start/stop.

3. Tuning control: Selects transmit/receive frequencies in VFO mode and memory channels in Memory Recall mode. Also provides:

• Menu A or Menu B selection of function or choices.

• Program Scan limits select to choose the boundaries for this type of scan.

• Scan direction select to choose if Scan progresses upward or downward in frequency.

• DTSS code select.

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

5. MN button: Selects the Memory Name mode.

6. POWER switch: Switches the transceiver ON or OFF.

7. SQL (Squelch) control: Adjusts the squelch threshold level. This allows you to mute speaker output while no stations are being received.

8. Microphone connector: Insert the 8-pin modular connector plug until the locking tab “clicks”.

9. MHz button: Selects the MHz mode. This allows you to use the Tuning control or the microphone [UP]/[DWN] buttons to change the transceiver frequency in 1 MHz steps. Also provides AM/FM mode select (some versions only).

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

11. TONE button: Switches the Tone function ON or OFF. When the optional TSU-8 is installed, also switches the CTCSS function ON or OFF. Also provides Automatic Tone frequency ID activate/deactivate.

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

1. Antenna cable: Connect an external antenna. When making test transmissions, connect a dummy load in place of the antenna. The antenna system or load should have an impedance of 50 Ω. The connector accepts a male PL-259 connector.

2. Power Input 13.8 V DC cable: Connect a 13.8 V DC power source. Use the supplied DC power cable.

3. Speaker jack: If you wish, connect an optional external speaker for clearer audio. Accepts a 3.5 mm diameter, 2-conductor plug.

1. UP button / 2. DWN button: Raises or lowers the VFO frequency, the memory channel number, the Tone/CTCSS frequency, or the DTSS code. Holding either button down causes the action to be repeated. Also, switches between values when selecting values for functions with multiple choices.

3. PTT (Push-to-talk) switch: Press to transmit; release to receive. Also used to exit various functions such as Scan, DTSS code select, or Tone/CTCSS frequency select.

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

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

6. VFO key / 7. MR key: Identical to the Front Panel functions of the same names. Both keys can be re-programmed, if desired.

8. PF key: Depending on which function you select by accessing “PF” in Menu B, the function of this key differs.

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

The display indicators have the following meanings:

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

• + -: Indicates the transmit frequency is offset (different) from the receive frequency. The symbol displayed (either “+” or “-“) indicates the direction of the offset. “- +” appears for a split-frequency memory channel.

• R: Indicates the Reverse function is ON. Transmit and receive frequencies are reversed.

• T/CT: “T” indicates the subaudible Tone encoder function 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 Resume is in effect.

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

• Frequency Display: Displays the transmit/receive frequency, frequency step, Offset frequency and other data. The 1 MHz decimal point blinks while the transceiver is scanning.

• Memory Channel Display: Displays the currently selected memory channel number. The first digit displays “A” or “B” depending on which Menu is being accessed.

• Star icon: Indicates the selected memory channel is locked-out and will not be scanned by Memory Scan.

• Spade icon: Indicates AM receive mode is ON (available only on some versions).

• TOT: Indicates the Time-out Timer function is ON. Blinks while accessing Menu B, “TOT”.

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

• LM: Indicates whether Low (L) or Medium (M) transmit output power is selected. When neither “L” nor “M” is visible, High output power is selected.

• F: Appears when the [F] button is pressed. Indicates alternate functions of multiple-function buttons can be accessed.

• BUSY: Indicates the squelch is open and the frequency is “busy”. If using CTCSS or DTSS, it indicates a signal with the correct code is being received.

• S-meter/RF power meter: In Receive, acts as an S-meter. In Transmit, acts as an RF power meter.

• ON AIR: Indicates the transceiver is in Transmit mode with a transmit frequency selected that is within a transmit band.

Switching Power ON/OFF

1. Switch ON the DC power supply (for fixed station operation).

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

3. To switch OFF the transceiver, 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 from the speaker when no signals are present. Turn the SQL control clockwise to just eliminate the background noise when no signal is present. You will hear sound only while a station is actually 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 frequency step at a time.

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

• If you cannot select a particular receive frequency, the frequency step size needs to be changed.

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

Press [UP] or [DWN] once to change the receive frequency by one frequency step in the direction indicated by the button. Pressing and holding either button causes the frequency to step repeatedly in one direction until the button is released.

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

Frequencies can also be selected via the microphone keypad using the Keypad Direct Entry feature.

Transmitting

When ready to begin transmitting, press and hold [PTT] and speak in a normal tone of voice. Speaking too close to the microphone, or too loudly, may increase distortion and reduce intelligibility of your signal at the receiving station.

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], [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 selected or configured via software-controlled menus (Menu A and Menu B). Menu A is used for frequently changed functions, while Menu B is for less frequently changed functions.

Menu Access

1. To access Menu A, press [F] (1 s).

To access Menu B, press [F]+ POWER ON.

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

3. The method for selecting the desired menu selection differs depending on the menu function:

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

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

• For specific functions like DTSS Code, Memory Channel Lockout, Program Scan, and DTMF Number Storing/Confirmation, refer to the corresponding sections in the manual for detailed instructions.

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

Note: If no action is taken for approximately 10 seconds after a menu is accessed, the frequency display is restored.

¹ Cannot be selected in the Memory Channel mode.

² The minimum selectable offset frequency is dependent on the current frequency step.

³ Cannot be selected in the VFO or Call Channel mode.

¹ Available on some TM-261A versions only.

² Available only when the optional TSU-8 is installed.

Operating through a repeater allows for communication over greater distances. Most repeaters use a separate receive and transmit frequency. You can set this up by selecting an offset frequency and direction. Some repeaters also require a subaudible tone to be transmitted.

Flow Chart for Repeater Access:

1. Select a receive frequency.

2. Select an offset frequency.

3. Select an offset direction.

4. Activate the Tone function, if necessary.

5. Select a Tone frequency, if necessary.

6. Press microphone [PTT] to transmit.

Selecting Offset Frequency:

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

2. Select “O.S”. The current offset frequency appears.

3. Select the appropriate offset frequency within 20 MHz of the receive frequency by turning the Tuning control or using the microphone [UP]/[DWN] keys.

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

Selecting Offset Direction:

Press [F], [SHIFT] to cycle through the offset directions: Simplex -> + -> -.

Activating Tone Function:

Each press of [TONE] switches through the choices: No Indicator -> TONE (“T”) -> CTCSS (“CT”).

Selecting a Tone Frequency:

To select the same Tone frequency for transmitting and receiving, access “TO” in Menu A. The available Tone frequencies are listed in the manual.

When used while monitoring a repeater, the Reverse function allows you to manually check the signal strength of a station accessing the repeater. If the station’s signal is strong, it’s best to move to a simplex frequency to continue the contact and free up the repeater.

Press [REV] to toggle the Reverse function ON or OFF.

• The receive frequency and the transmit frequency are exchanged. “R” appears on the display when the function is ON. The default is OFF.

• If any Tone frequency is selected for “TONE.RX” in Menu B, the RX Tone frequency and the TX Tone frequency also are reversed.

• If reversal would place the receive frequency outside the receive frequency range, an error beep sounds when [REV] is pressed. No reversal occurs.

• Automatic Repeater Offset does not function while Reverse is ON.

The transceiver has 62 memory channels (1 ~ 62) for storing frequencies and related data. The data listed in the table below can be stored in each memory channel.

Storing Simplex Memory Channels

1. Select the desired frequency and associated data (Tone, CTCSS, DTSS, etc.) using VFO mode, Memory Recall, or the Call channel.

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 selected frequency and associated data are stored in the memory channel.

Storing Split Memory Channels

1. Select the desired receive frequency and associated data.

2. Press [F] to enter Function Select mode.

3. Select the desired memory channel.

4. Press [MR] (1 s). “- +” appears.

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

6. Press [MR]. The frequencies are stored in the memory channel.

Recalling Memory Channels

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

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

Erasing Memory Channels

1. Press [MR] to select Memory Recall.

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

3. Switch OFF the power to the transceiver.

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

The Call channel can be used to store a frequency and related data that you want to recall frequently.

Recalling the Call Channel

Simply press microphone [CALL] to retrieve the contents of the Call channel. “C” appears on the Display.

Changing Call Channel Contents (Simplex)

1. Select the desired frequency and associated data using VFO mode or Memory Recall.

2. Press [F], microphone [CALL]. The selected frequency and data are stored in the Call channel.

Changing Call Channel Contents (Split)

1. Select the desired receive frequency and associated data.

2. Press [F], microphone [CALL] (1 s). “- +” appears.

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

4. Press microphone [CALL]. The frequencies are stored in the Call channel.

If your transceiver seems to be malfunctioning, initializing it may resolve the problem.

Partial Reset (VFO)

To initialize all settings except the memory channels, the Call channel, and the Menu settings, press [VFO]+ POWER ON.

Full Reset (Memory)

Remember that this erases all data from all memory channels.

1. To initialize all settings, press [MR]+ POWER ON.

2. While the full display is visible, press [MR] again. The VFO, memories, and Menu settings are reset.

Note: After the display appears in step 1, you must execute step 2 within approximately 10 seconds or the Full Reset will be aborted.

You can name memory channels using up to 6 characters and 5 dots. When you recall a named memory channel, its name appears on the display instead of the stored frequency.

Storing a Name in Memory

1. Press [MR] to select Memory Recall.

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

3. Switch OFF the power to the transceiver.

4. Press [MN]+ POWER ON. The first digit blinks.

5. Turn the Tuning control, or press microphone [UP]/[DWN], to select the first digit. To enter a dot after the first digit, press [MR].

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

7. Repeat Steps 5 and 6 to enter up to 6 digits. When you enter less than 6 digits, press [MHz], [F], [TONE], [REV], or microphone [PTT] to complete entry.

After storing a name, pressing [MN] toggles between name display and frequency display for the memory channel.

This transceiver provides several types of Scan for hands-off monitoring.

Scan Resume Methods

Before scanning, choose a resume method in Menu A (“SCN”).

• Time-Operated Scan: The transceiver stops on a signal for approximately 5 seconds, then continues scanning even if the signal is still present.

• Carrier-Operated Scan: The transceiver stops on a signal and remains there until the signal drops out. There is a 2-second delay before scanning resumes.

Performing a VFO Scan

Press [VFO] (1 s) to start or stop VFO scan. The 1 MHz decimal blinks while scanning. To reverse direction, turn the Tuning control or press microphone [UP]/[DWN].

Performing a Memory Scan

Press [MR] (1 s) to start or stop Memory Scan. Only unlocked channels containing data will be scanned. To reverse direction, turn the Tuning control or press microphone [UP]/[DWN].

Locking Out Memory Channels

1. Select the memory channel to be locked out.

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

3. Select “MR.L”.

4. Press [VFO] to toggle the lockout status ON or OFF. A star icon appears when the channel is locked out.

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

This scan is similar to VFO Scan but allows you to set frequency limits.

Setting Scan Limits

1. Press [F]+ POWER ON to access Menu B.

2. Select “PGM.SCN”.

3. Press [VFO]. “LO” and the current lower limit appear.

4. Turn the Tuning control, or press microphone [UP]/[DWN], to display the desired lower limit. Press [MHz] to change in 1 MHz steps.

5. Press [VFO]. “UP” and the current upper limit appear.

6. Turn the Tuning control, or press microphone [UP]/[DWN], to display the desired upper limit.

7. Press [VFO] to set the upper limit.

8. Press [F] or microphone [PTT] to exit Menu B.

Using Program Scan

1. Select a frequency between the programmed scan limits.

2. Press [VFO] (1 s) to start the scan.

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

4. To cancel Program Scan, press any key other than microphone [UP]/[DWN].

CTCSS is available only when the optional TSU-8 unit is installed. It allows you to choose which stations will receive your transmissions by using a subaudible tone.

Using CTCSS

1. Select the desired RX and TX Tone frequencies in the menu system (“TO” in Menu A for TX, “TONE.RX” in Menu B for RX).

2. Repeatedly press [TONE] until “CT” appears on the Display.

3. When you are called: The squelch of your transceiver opens only when the selected RX Tone is received.

4. When you make a call: Press and hold microphone [PTT]. The selected TX Tone is superimposed on your transmitted signal.

Automatic Tone Frequency ID

This function automatically identifies the incoming Tone frequency on a received signal.

1. Press [TONE] (1 s) to toggle the function ON or OFF. A Tone frequency display replaces the regular frequency display.

2. When a signal is received, the transceiver scans to identify the Tone frequency. When identified, an alarm beeps, and the Display blinks.

3. Press any key to cancel the function.

DTSS provides a method to selectively communicate with specific stations. The squelch opens only when the same 3-digit DTMF code (000 to 999) is received that is programmed in your transceiver.

Storing DTSS Codes (Using Tuning Control)

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

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

3. Press [VFO]. The first digit blinks.

4. Use the Tuning control or microphone [UP]/[DWN] to select the first digit.

5. Repeat Steps 3 and 4 to select the second and third digits.

6. Press [VFO] again to complete your selection.

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

Using DTSS

1. Store the appropriate DTSS code.

2. Press [F], [DTSS]. “DT” appears when DTSS is ON. Each press toggles the function ON and OFF.

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

4. When you make a call: Press and hold microphone [PTT] to transmit your DTSS code. The code is transmitted for about 0.5 second. After establishing contact, you can switch the DTSS function OFF.

DTMF functions require an MC-53DM microphone.

Making DTMF Calls

To make a DTMF call, hold down the microphone [PTT] and press [0] ~ [9], [A], [B], [C], [D], [*], or [#]. The corresponding DTMF tones are transmitted.

Storing DTMF Numbers for the Automatic Dialer

1. Press [F]+ POWER ON to access Menu B.

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 (up to 16 digits).

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.

Transmitting Stored DTMF Numbers

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

2. Press a single key [0] ~ [9] to select a DTMF memory channel. The stored number scrolls across the display accompanied by DTMF tones.

You can enter frequency or memory channel digits directly from the MC-53DM microphone.

Frequency Entry

1. Press [VFO] to select VFO mode.

2. Access “PF” in Menu B, and select “ENTer”.

3. Press microphone [PF]. The display for Direct Frequency Entry appears.

4. Use the microphone keypad to enter the desired frequency, from the most significant digit to the least significant.

Memory Channel Number Entry

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

2. Access “PF” in Menu B, and select “ENTer”.

3. Press microphone [PF]. The display for Direct Memory Channel Entry appears.

4. Use the microphone keypad to enter 2 digits. For example, to recall channel 3, enter “03”.

Choosing the correct step size is essential to select your exact receive frequency. To change the frequency step size, select the VFO mode, and access “F.S” in Menu A. You cannot use this function if you access Menu A after a memory channel or the Call channel is recalled. Changing between step sizes may result in a change of the displayed frequency, as shown in the accompanying tables.

Default Step Sizes:

Frequency Changes (from 5, 10, 15, 20, or 25 kHz to 12.5 kHz)

Frequency Changes (from 12.5 kHz to 5, 10, 15, 20, or 25 kHz)

Time-Out Timer (TOT)

This feature restricts a single transmission to a maximum of 10 minutes. When TOT times out, the transceiver beeps and returns to Receive. Access “TOT” in Menu B to toggle it ON or OFF.

Busy Channel Lockout (BCL)

This prevents you from transmitting on a channel that is already in use. Pressing [PTT] while the channel is busy causes an audible warning tone, and the transceiver will not transmit. Access “BCL” in Menu B to toggle it ON or OFF.

Automatic Power Off (APO)

APO turns off the transceiver’s power after 3 hours of inactivity (no button presses, no tuning control movement). One minute before shutdown, “APO” starts blinking and warning tones sound. Access “APO” in Menu B to toggle it ON or OFF.

Transceiver Lock

This mode prevents accidental changes to settings at the transceiver itself, suitable for mobile installations where you operate mainly from the microphone. Press [F], [LOCK] to toggle Transceiver Lock ON or OFF. When ON, a key icon appears and only the POWER switch, [F], [F], [LOCK], and microphone keys are enabled.

The Programmable Function keys are [PF], [MR], and [VFO] on the face of the microphone. You can change the default functions assigned to these keys.

Re-assignment Procedure:

1. Press one of the following key combinations depending on which key you want to re-assign:

• Microphone [PF]+ POWER ON (“PF1” appears)

• Microphone [MR]+ POWER ON (“PF2” appears)

• Microphone [VFO]+ POWER ON (“PF3” appears)

2. Press the key or key combination on the Front Panel that you want to assign to the Programmable Function key pressed in Step 1.

• The following types of Front Panel key functions can be assigned: [KEY], [KEY] (1 s), [F], [KEY].

• The following cannot be assigned: [KEY]+ POWER ON, [F], [F] (1 s), POWER switch, Tuning control, VOL control, SQL control.

To restore the default functions, perform a Full Reset.

You can use almost any computer to control a Terminal Node Controller (TNC) for packet operation.

• Connect your TNC to the microphone connector on the transceiver Front Panel using a cable with an 8-pin modular plug.

• Do not share a single power supply between the transceiver and the TNC.

• Keep as wide a separation as possible between the transceiver and computer to reduce noise-pickup.

1200 bps OPERATION

Using a modulator input level that is far different from the optimum 40 mVp-p specifications may result in deterioration of S/N ratio or signal distortion.

Note:

• Transmit data input sensitivity is 40 mVp-p. This is suitable for a typical 1200 bps TNC or other data communications equipment.

• The TX delay parameter on your TNC should be set for 300 ms by using your computer.

• Packet operation requires a full-scale S-meter reading for reliable communication.

Remove the controls from the transceiver when they become soiled and clean them with a neutral detergent and warm water. Use a neutral detergent (no strong chemicals) and a damp cloth to clean the case.

If the transceiver will not power up after connecting a 13.8 V DC power supply and pressing [POWER], and nothing appears on the Display, check the following:

1. Probable Cause: The power cable is connected backwards.

Corrective Action: Connect the supplied DC Power Cable correctly: Red to (+); Black to (–).

2. Probable Cause: One or more of the power cable fuses are open.

Corrective Action: Look for the cause of the blown fuse/fuses. After inspecting and correcting any problems, install new fuses with the same ratings.

3. Probable Cause: The connectorized cable has not been correctly connected.

Corrective Action: Connect the connectorized cable correctly.

Probable Cause: Memory Recall or the Call channel is selected.

Corrective Action: Press [VFO] to switch to VFO mode.

Probable Cause: The Transceiver Lock function is ON.

Corrective Action: Press [F], [LOCK] to unlock the transceiver.

If you cannot select memory channels by turning the Tuning control or pressing microphone [UP]/[DWN] when using Memory Recall, check the following:

1. Probable Cause: No data has been saved in any memory channels, or entered data was erased by a Full Reset.

Corrective Action: Store data in some memory channels.

2. Probable Cause: The Call channel is selected.

Corrective Action: Press [MR] to switch to Memory Recall.

If you cannot transmit even though you press [PTT], check the following:

1. Probable Cause: The microphone plug is not inserted completely in the Front Panel connector.

Corrective Action: Switch OFF the power, ensure the microphone connector on the Front Panel has no foreign objects in it, then insert the microphone plug until the locking tab clicks in place.

2. Probable Cause: You have selected a transmit offset that places the transmit frequency outside the transmit band range.

Corrective Action: Press [F], [SHIFT] one or two times so neither “+” nor “-” are visible.

If you are having trouble with packet connections, check the following:

1. Probable Cause: Your frequency differs from the target station’s frequency.

Corrective Action: Adjust your frequency using the Tuning control.

2. Probable Cause: The modulation level from the TNC is incorrect.

Corrective Action: Adjust the TNC modulation level according to the TNC instruction manual.

3. Probable Cause: There is multi-path distortion.

Corrective Action: Reorient or relocate the antenna. The strongest signal does not always provide the best operation on packet.

4. Probable Cause: The TX delay time parameter in your TNC is set incorrectly.

Corrective Action: Set the TX delay time to more than 300 ms.

CAUTION: Always switch OFF the power and unplug the DC power cable first.

1. Remove the two screws from the upper cover of the transceiver.

2. Remove the upper cover.

3. Hold the TSU-8 unit with the large IC facing downward, and insert the connector on the TSU-8 unit into the 8-pin connector as shown. Take care to keep the TSU-8 horizontal when inserting it into the 8-pin connector.

4. Replace the upper cover and screws.

Transmitter Specifications

Receiver Specifications