SELECTIVE CALL

CTCSS AND DCS

You may sometimes want to hear calls from only specific persons or groups. In this case, use Selective Call. This transceiver is equipped with CTCSS (Continuous Tone Coded Squelch System) and DCS (Digital Coded Squelch). These Selective Calls allow you to ignore (not hear) unwanted calls from other persons who are using the same frequency. The transceiver unmutes only when it receives a signal having the same CTCSS tone or DCS code.

Note: CTCSS and DCS do not cause your conversation to be private or scrambled. It only relieves you from listening to unwanted conversations.

CTCSS

A CTCSS tone is a sub-audible tone and is selectable from among the 42 tone frequencies listed in the table on page 47. The list includes 37 EIA standard tones and 5 non-standard tones.

To activate CTCSS, press [F], [CALL].

Received

TM-271

9

Rejected

CTCSS freq.: 82.5 Hz

Rejected

TM-271

CTCSS freq.: 82.5 Hz

TM-271

CTCSS freq.: 100 Hz

TM-271

¥As you press [F], [CALL], the selection cycles as follows:

ÒOFFÓ ÒTONEÓ ÒCTCSSÓ ÒDCSÓ ÒOFFÓ.

¥ÒCTÓ appears on the upper part of display, indicating that the CTCSS function is activated.

When CTCSS is ON, you will hear calls only when the selected CTCSS tone is received. To answer the call, press and hold Mic [PTT], then speak into the microphone.

Note:

You cannot use the CTCSS and Tone/ DCS functions

simultaneously. Switching the CTCSS function ON after having

activated the Tone/ DCS functions deactivates the Tone/ DCS

functions.

If you select a high CTCSS frequency, receiving audio or noise

that contains the same frequency portions may cause CTCSS to

function incorrectly. To prevent noise from causing this problem,

select an appropriate squelch level {page 14}.

While transmitting the 1750 Hz tone by pressing [CALL]

{page 25}, the transceiver does not transmit the CTCSS tone.

CTCSS OFF

46

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Image 53
Kenwood TM-271A, TM-271E instruction manual Selective Call, Ctcss and DCS, Rejected

TM-271A, TM-271E specifications

The Kenwood TM-271A and TM-271E are robust dual-band transceivers designed for amateur radio enthusiasts looking for reliability, functionality, and ease of use. Both models operate in the VHF and UHF bands, specifically covering 144-148 MHz and 430-450 MHz, respectively. This versatility allows users to communicate across varied frequencies, making them suitable for a wide range of applications, from casual conversations to emergency communications.

One of the standout features of the TM-271A and TM-271E is their compact size, making them an ideal choice for mobile operations. Despite their small footprint, these radios pack a punch with a maximum transmit power of 50 watts in the VHF band and 35 watts in the UHF band. This power output ensures clear and effective communication over long distances, essential for outdoor activities and emergency situations.

The user-friendly interface of the TM-271 models includes a large, backlit LCD display, which provides clear visibility in various lighting conditions. The controls are intuitively arranged, allowing users to navigate functions with ease. Moreover, both models come equipped with an alphanumeric memory, allowing for the storage of up to 200 memories for easy access to frequently used frequencies.

Advanced features such as a built-in CTCSS (Continuous Tone-Coded Squelch System) and DCS (Digital Coded Squelch) enhance communication clarity by minimizing unwanted noise and ensuring that only desired signals are received. The TM-271A and TM-271E also support a wide range of modulation modes, including FM, allowing versatility in communication styles.

In terms of durability and build quality, the Kenwood TM-271 series excels with a rugged design that withstands the rigors of mobile use. The units are also equipped with a front-facing speaker that delivers excellent audio quality, ensuring clear communications even in noisy environments.

Another notable feature is the wideband reception capability, allowing users to listen to signals outside of the amateur bands, making these transceivers more versatile for everyday monitoring of public safety channels and other broadcasts. Furthermore, the inclusion of a built-in diagnostic function aids users in troubleshooting, ensuring that the radio remains in optimal working condition.

In conclusion, the Kenwood TM-271A and TM-271E are outstanding choices for amateur radio operators seeking a powerful, feature-rich, and user-friendly dual-band transceiver. Their combination of advanced technology, compact design, and rugged reliability makes them a popular choice among both novice and experienced operators in the radio community.