Cobra Electronics 21 LTD ユーザーズマニュアル

The Citizens Band lies between the shortwave broadcast and 10-meter Amateur
radio bands, and was established by law in 1949. The Class D two-way commu-
nications service was opened in 1959. (CB also includes a Class A citizens band

and Class C remote control frequencies.)
FCC regulations permit only “transmissions” (one party to another) rather than

“broadcasts” (to a wide audience). Thus, advertising is not allowed on CB
Channels because that is “broadcasting.”

Cobra proudly introduces the first Patent Pending technology that dramatically
improves the transmission and reception of CB radio signals.
This revolutionary system re c o n f i g u res the transmission signal which allows it to
be transferred more effectively through cluttered airwaves. It literally “punches”
your message through the hundreds of thousands of signals that are in the air. A t
the same time, S o u n d Tracker system dynamically adjusts the relationship between
the  signal  and  static  commonly  re f e r red  to  as  noise.  This  allows  Cobra’s
S o u n d Tr a c k e r system to significantly reduce the amount of static on all incoming
CB signals. The system can be further optimized when two SoundTracker CB’s are
used to talk to each other.
The end result is a clearer, cleaner sounding reception of signals and more
powerful transmissions which dramatically improve CB Communications

All transmitter adjustments other than those supplied by the manufacture r
as front panel operating controls, must be made by, or under the supervision
of, the holder of an FCC-issued general Radio-Telephone Operator’s License.
Replacement or substitution of transistors, regular diodes or other parts of
a unique nature, with parts other than those recommended by Cobra, may
cause violation of the technical regulations of Part 95 of the FCC Rules, or
violation of Type Acceptance requirements of Part 2 of the Rules.
You should read and understand Part 95 (included with this unit) of the
FCC Rules and Regulations, before operating your Cobra radio, even
though the FCC no longer requires you to obtain an operators license.

1

The CB Story ............................................................................................1
SoundTracker System ............................................................................1
Specifications ........................................................................................2,3
Installation

Location..................................................................................................4
Mounting Connections....................................................................4, 5
CB Antenna ..........................................................................................6
Ignition Noise Interference ................................................................7
In House Operation..............................................................................7

Controls and Indicators ............................................................8, 9, 10
Operating Procedure to Receive ......................................................11
Operating Procedure to Transmit ....................................................12

How SoundTracker Works................................................................13

Maintenance and Adjustment ............................................................14
Appendix

Ten Code..............................................................................................15
A Few Rules That Should Be Obeyed ............................................16
How Your CB Can Serve You ..........................................................16

Warranty Service Instructions ............................................................17
Limited Two Year Warranty ................................................................18
Accessories..................................................................Inside Back Cover

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