Select the desired channel.
Set the DYNAMIKE control fully clockwise.

21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 15

Operation (Cont.)

Operating Procedure to Transmit

1. Be sure the operator has read and understands part 95, F.C.C. Rules and Regulations prior to operating the transmitter.

2.

3.

4. The receiver and transmitter are controlled by the press-to-talk switch on the microphone. Press the switch and the transmitter is activated; release switch to receive. When transmitting (on a clear channel), hold the microphone two inches from the mouth and speak clearly in a normal voice.

Be sure the antenna is properly connected to the radio before transmitting. Prolonged transmitting without an antenna, or a poorly matched antenna, could cause damage to the transmitter.

Operating Procedure for Public Address

1. Connect a PA speaker to the PA jack provided on the rear panel.

2. Place PA/CB/ANLswitch into the PA position.

3. Depress push-to-talk switch on mic—speak in normal voice.

4. Adjust PA speaker volume with front panel DYNAMIKE control.

When the Volume control is rotated clockwise, activity on the CB channel will be heard through the PA speaker.

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How SoundTracker Works

SOUNDTRACKER SYSTEM

While previous systems only “blanked out” or limited noise in higher sound frequencies, the revolutionary new SoundTracker System actually reduces noise while leaving the signal intact in the reception mode. In the transmission mode, it actually strengthens the signal, providing you with a significant reduction in noise on reception and transmission.

Sound clarity is measured by the ratio of the signal level to the noise level. The higher the signal-to-noise ratio, the better the sound.

HOW SOUNDTRACKER WORKS

On Reception–“Cuts Noise Coming In”

With a normal CB, distant signals fall below the squelch level and are unintelli- gible. With a SoundTracker CB, the noise level is cut by up to 90%, which increases the signal-to-noise ratio and dramatically improves signal clarity. This also allows you to significantly reduce the squelch level, which greatly expands your listening range.

On Transmission–“Strengthens Signals Going Out”

A SoundTracker CB strengthens the transmit signal by more effectively using the available RF power output of the CB. The result is improved transmission signal clarity and an expanded transmission range.

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Cobra Electronics 21 LTD operating instructions How SoundTracker Works, Operating Procedure to Transmit
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21 LTD specifications

Cobra Electronics 21 LTD is a versatile Citizen Band (CB) radio designed for seamless communication in a wide array of environments, making it a staple for truck drivers, outdoor enthusiasts, and hobbyists alike. Known for its reliability and quality, the 21 LTD combines advanced technology with user-friendly features, ensuring clear and efficient communication.

One of the standout features of the Cobra 21 LTD is its compact design, which makes it easy to install in trucks, cars, and even boats. Despite its small size, it accommodates a comprehensive 40-channel system, allowing users to select from various frequencies, ensuring they can find optimal communication channels regardless of their location.

Equipped with a powerful, built-in noise-canceling microphone, the 21 LTD is adept at minimizing background noise, producing crystal-clear audio even in noisy environments. This feature is particularly beneficial for truck drivers traversing busy highways, ensuring that both transmitted and received messages maintain high quality. Additionally, the radio boasts Automatic Noise Limiting (ANL) technology, which further enhances sound quality by reducing static and interference.

The Cobra Electronics 21 LTD also includes a front-firing speaker for improved audio clarity and a large, easy-to-read analog gauge for channel selection and signal strength monitoring. This design enhances operational convenience, allowing users to stay focused on the road while effortlessly adjusting settings.

Another notable characteristic is the inclusion of a PA (Public Address) feature, which enables users to connect an external speaker. This is especially useful for communicating with larger groups or providing instructions at job sites. Furthermore, the radio features a built-in SWR (Standing Wave Ratio) meter, an essential tool for ensuring proper antenna alignment and optimizing signal performance.

In terms of durability, the Cobra 21 LTD is designed to endure the rigors of outdoor use, featuring a robust construction that can withstand vibrations and varying weather conditions. With an easy installation process and compatibility with various microphones and accessories, this radio is perfect for both seasoned CB users and newcomers.

In conclusion, the Cobra Electronics 21 LTD is a powerful and reliable CB radio that boasts numerous user-friendly features, advanced technologies, and rugged characteristics. Whether for long hauls, outdoor adventures, or casual communication, the 21 LTD stands out as a top choice for those who value quality and convenience.
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