Оценок - 3, средний балл: 4.7
(
)
)
|
Фрагмент инструкции
The Class D two-way communications 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.” “Cuts Static coming in, adds Punch going out!” 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 21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 5 Specifications FREQUENCY RANGE The COBRA21 LTD ST transceiver represents one of the most advanced AM two- way radios ever designed for use as a Class D station in the Citizens Radio Service. This unit features advanced Phase Lock Loop (PLL) circuitry providing complete coverage of all 40 channels as shown below. Channel Channel Frequency Channel Channel Frequency in MHz in MHz 1 26.965 21 27.215 2 26.975 22 27.225 3 26.985 23 27.255 4 27.005 24 27.235 5 27.015 25 27.245 6 27.025 26 27.265 7 27.035 27 27.275 8 27.055 28 27.285 9 27.065 29 27.295 10 27.075 30 27.305 11 27.085 31 27.315 12 27.105 32 27.325 13 27.115 33 27.335 14 27.125 34 27.345 15 27.135 35 27.355 16 27.155 36 27.365 17 27.165 37 27.375 18 27.175 38 27.385 19 27.185 39 27.395 20 27.205 40 27.405 The COBRA21 LTD ST has a vastly superior receiver which includes noise blanker c i rcuitry and an automatic noise limiter. The receiver also features increased p rotection against cross modulation and strong adjacent channel signals. To obtain maximum performance please read carefully the descriptions and operating instructions in this manual. Fill out below; keep for your records. Serial No. Date of Purchase Dealer Name Keep this manual for detailed information about your Cobra CB radio. SAVE YOUR SALES RECEIPT, CARTON AND PACKING FOR POSSIBLE FUTURE USE. 2 Specifications (cont.) GENERAL Channels 40 Frequency Range 26.965 to 27.405 MHz. Frequency Control Phase Lock Loop (PLL) synthesizer. Frequency Tolerance 0.005%. Operating Temperature Range -30° C to + 50° C. Microphone Plug-in dynamic. Input Voltage 13.8VDC nom.(positive or negative ground). Current Drain Transmit: AM full mod., 1.5A(maximum) Receive: Squelched, 0.3A; full audio output, 1.2A Size (nominal). 5 3/4” W x 1 3/4” H x 7 1/2” D . Weight 1.2 lbs. Antenna Connector UHF, SO-239. Semiconductors 26 transistors, 26 diodes, 4 integrated circuits. Meter Illuminated; indicates relative power output and received signal strength. TRANSMITTER Power Output 4 watts. Modulation AM (Amplitude Modulation). Frequency Response 300 to 3000 Hz. Output Impedance 50 ohms, unbalanced. RECEIVER Sensitivity Less than 1 .V for 10dB (S+N)/N. Selectivity 6dB @ 7 KHz, 60 dB @ 10 KHz. Image Rejection 80 dB, typical. Adjacent-Channel Rejection 60 dB, typical. IF Frequencies Double Conversion: 1st: 10.695 MHz. 2nd: 455 KHz. Automatic Gain Control (AGC) Less than 10 dB change in audio output for inputs from 10 to 50,000 microvolts. RF Gain Control Adjustable for optimum signal reception. Noise Blanker RF type. Squelch Adjustable; threshold less than 1.V. Audio Output Power 4 watts. Frequency Response 300 to 3000 Hz. Distortion Less than 7% @ 3 watts @ 1000 Hz. Built-in Speaker 16 ohms, round. External Speaker (Not Supplied) 8 ohms; disables internal speaker when connected. PA SYSTEM Power Output 4 watts into external speaker. External Speaker for PA 8 ohms, when PA-CB switch is in PA, the PA speak...