21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 11

Operation

Controls and Indicators

Refer to controls, indicators and connectors as illustrated below:

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A. Front Panel

1. MICROPHONE CONNECTOR. Front panel microphone connector.

2. OFF/ON/VOLUME. Turn clockwise to turn power on and set the desired listening volume.

3. SQUELCH. This control is used to cut off or eliminate receiver back- ground noise in the absence of an incoming signal. For maximum receiver sensitivity it is desired that the control be adjusted only to the point where the receiver background noise or ambient background noise is eliminated. Adjust until the receiver noise disappears. This will require the incoming signal to be slightly stronger than the average receiver noise. Further clockwise rotation will increase the threshold level which a signal must overcome in order to be heard. Only strong signals will be heard at a maximum clockwise setting.

4. RF GAIN. Adjust as required to optimize signal. This control is used primarily to optimize reception in strong signal areas. Gain is reduced by counterclockwise rotation of the control.

5. CHANNEL SELECTOR SWITCH. This switch selects any one of forty Citizens Band channels desired. The selected channel is indicated by the LED readout, directly above the channel selector knob.

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Operation (Cont.)

6. RX/TX LED INDICATOR. When your radio is in the CB receive mode, the LED will be green. When in transmit mode, the LED will be red.

7. LED CHANNEL DISPLAY. The selected channel will be displayed.

8. CB-PA SWITCH: Selects the mode of operation. In the CB position, the PA function is disabled and the unit will transmit and receive on the selected frequency. The PA function should not be used unless a PA speaker is connected. NOTE: ANL (Automatic Noise Limiter) is a non-switchable feature that is always on to reduce background noise.

9. S-METER.Swings proportionally to the strength of the incoming signal during receiving.

RF-METER.Swings proportionally to the RF output power while transmitting.

10. SOUNDTRACKER™INDICATOR. Ared LED will illuminate when the SoundTracker system is engaged on your CB.

11. SOUNDTRACKER™ SWITCH. Depressing this button turns on the SoundTracker system in your CB.

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Cobra Electronics 21 LTD operating instructions Operation, Controls and Indicators, Front Panel
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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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